diff --git a/code/file-preview/.trae/documents/task_fix_plan.md b/code/file-preview/.trae/documents/task_fix_plan.md
new file mode 100644
index 00000000..fbd5be70
--- /dev/null
+++ b/code/file-preview/.trae/documents/task_fix_plan.md
@@ -0,0 +1,45 @@
+# Task 关闭按钮修复计划
+
+## 问题分析
+
+根据代码审查，`g3-task-close` 点击无反应的核心问题在于：
+
+1. **事件绑定方式错误**：使用直接绑定而非事件委托
+2. **taskId 未绑定到 DOM**：无法通过 DOM 获取当前任务 ID
+3. **closeTask 方法不完善**：只删除数据，未删除对应的 DOM 元素
+
+## 修复方案
+
+### 1. 修改 renderTaskCenter 方法
+- 在 DOM 元素上添加 `data-task-id` 属性
+- 移除直接的事件绑定
+
+### 2. 修改 closeTask 方法
+- 同时删除数据和对应的 DOM 元素
+
+### 3. 添加事件委托（在初始化时绑定）
+- 使用事件委托绑定 `.g3-task-close` 点击事件
+
+### 4. 检查 pointer-events 样式
+- 确保 `.g3-task-close` 按钮可点击
+
+## 修改文件
+
+- `d:\workspace\code\file-preview\g3-file\index.js`
+
+## 修改步骤
+
+1. 在 `renderTaskCenter` 的 HTML 模板中添加 `data-task-id`
+2. 移除 `renderTaskCenter` 中的直接事件绑定
+3. 修改 `closeTask` 方法，添加 DOM 删除逻辑
+4. 在初始化时添加事件委托绑定
+
+## 风险评估
+
+- 低风险：修改局部代码，不影响其他功能
+- 需确保事件委托只绑定一次
+
+## 验证方式
+
+1. 点击关闭按钮，检查控制台是否输出正确的 taskId
+2. 确认任务数据和 UI 都被正确移除
\ No newline at end of file
diff --git a/code/file-preview/g3-file/.trae/documents/optimize-g3file-plan.md b/code/file-preview/g3-file/.trae/documents/optimize-g3file-plan.md
new file mode 100644
index 00000000..6d9c7e00
--- /dev/null
+++ b/code/file-preview/g3-file/.trae/documents/optimize-g3file-plan.md
@@ -0,0 +1,425 @@
+# G3File 组件结构优化和缺陷修复计划
+
+## 一、P0 必须修复的问题
+
+### 1. 避免整列表重渲染（核心性能问题）
+
+**问题**：`updateFileStatus` 调用 `renderFileList()`，导致整个列表重新渲染 + 重新绑定事件
+
+**解决方案**：新增 `updateFileItem(fileId)` 方法，仅更新单个文件项
+
+```javascript
+updateFileItem: function (fileId) {
+  var file = this.getFileById(fileId);
+  var $item = this.$fileList.find(`.g3-file-item[data-id="${fileId}"]`);
+  if (!file || !$item.length) return;
+
+  // 更新 checkbox
+  $item.find(".g3-file-checkbox").prop("checked", this.selectedFiles.has(fileId));
+
+  // 更新 badge
+  var $badge = $item.find(".g3-status-badge");
+  if (file.status === "pending") {
+    $badge.attr("class", "g3-status-badge g3-status-pending").text(this.language.pending);
+  } else if (file.status === "uploading") {
+    $badge.attr("class", "g3-status-badge g3-status-uploading").text(this.language.uploading);
+  } else if (file.status === "failed") {
+    $badge.attr("class", "g3-status-badge g3-status-failed").text(this.language.uploadFailed);
+  } else if (file.status === "uploaded") {
+    $badge.attr("class", "g3-status-badge g3-status-uploaded").text(this.language.uploaded);
+  }
+
+  // 更新权限状态
+  var canDownload = this.hasPermission(file, "download");
+  var canView = this.hasPermission(file, "view");
+  var canDelete = this.hasPermission(file, "delete");
+  $item.find(".g3-action-download").toggleClass("is-disabled", !canDownload);
+  $item.find(".g3-action-preview").toggleClass("is-disabled", !canView);
+  $item.find(".g3-file-delete-btn").toggleClass("is-disabled", !canDelete);
+}
+```
+
+**修改点**：
+- `updateFileStatus` 方法中移除 `renderFileList()` 调用，改为 `updateFileItem(fileId)`
+
+---
+
+### 2. 预览逻辑设计缺陷（previewIndex 问题）
+
+**问题**：使用 `previewIndex` 作为预览定位，删除/新增文件会导致错位
+
+**解决方案**：改为使用 `currentPreviewFileId`
+
+**修改点**：
+1. 构造函数中：`this.previewIndex = 0` → `this.currentPreviewFileId = null`
+2. 新增方法 `getPreviewFileIndex()` 用于兼容 prev/next 导航
+3. `previewPrev()` 和 `previewNext()` 改为基于 `currentPreviewFileId` 计算
+4. `updatePreview()` 改为使用 `currentPreviewFileId` 获取文件
+5. `setPreviewFile()` 直接设置 `currentPreviewFileId`
+6. `setFiles()` 中：`this.previewIndex = 0` → `this.currentPreviewFileId = null`
+
+---
+
+### 3. Task Center 多任务支持
+
+**问题**：`this.currentTask` 只能存在一个任务，上传/下载会互相覆盖
+
+**解决方案**：改为 `this.tasks = new Map()` 多任务模型
+
+```javascript
+startTask: function (options) {
+  var task = {
+    id: options.id || G3FileUtils.generateUniqueId(),
+    title: options.title,
+    total: options.total || 0,
+    current: options.current || 0,
+    currentItem: options.currentItem || "",
+    success: 0,
+    failed: 0,
+    status: "running"
+  };
+  this.tasks.set(task.id, task);
+  this.renderTaskCenter(task.id);
+  this.lockUI();
+  return task.id;
+}
+
+updateTask: function (options) {
+  var task = this.tasks.get(options.id);
+  if (!task) return;
+  if (options.current !== undefined) task.current = options.current;
+  if (options.currentItem !== undefined) task.currentItem = options.currentItem;
+  this.updateTaskCenter(options.id);
+}
+
+finishTask: function (options) {
+  var task = this.tasks.get(options.id);
+  if (!task) return;
+  task.status = "finished";
+  task.total = options.total !== undefined ? options.total : task.total;
+  task.success = options.success || 0;
+  task.failed = options.failed || 0;
+  task.current = task.total;
+  this.updateTaskCenter(options.id);
+  this.tasks.delete(options.id);
+  if (this.tasks.size === 0) {
+    this.unlockUI();
+  }
+}
+```
+
+**修改点**：
+- `this.currentTask` → `this.tasks = new Map()`
+- `renderTaskCenter(taskId)` 和 `updateTaskCenter(taskId)` 接收 taskId 参数
+- `closeTask(id)` 从 `this.tasks` 中删除任务
+
+---
+
+## 二、P1 重要优化
+
+### 4. 事件绑定优化
+
+**问题**：每次 `renderFileList` 后都调用 `bindFileItemEvents` 重新绑定
+
+**解决方案**：使用事件委托，在 `bindEvents` 中统一绑定一次
+
+```javascript
+bindEvents: function () {
+  var self = this;
+
+  // 文件列表事件委托（只在 init 时绑定一次）
+  this.$fileList
+    .on("click", ".g3-action-preview", function (e) { ... })
+    .on("click", ".g3-action-download", function (e) { ... })
+    .on("change", ".g3-file-checkbox", function (e) { ... })
+    .on("click", ".g3-file-delete-btn", function (e) { ... })
+    .on("click", ".g3-file-item", function (e) { ... })
+    .on("click", ".g3-action-more", function (e) { ... });
+
+  // 其他事件保持不变...
+}
+```
+
+**修改点**：
+- `renderFileList()` 中移除 `bindFileItemEvents()` 调用
+- `bindFileItemEvents()` 方法可移除或保留（如果外部需要单独调用）
+
+---
+
+### 5. 上传并发控制
+
+**问题**：`handleUpload` 中 forEach 并发无限制
+
+**解决方案**：使用 async pool 实现并发控制
+
+```javascript
+handleUpload: function (files) {
+  var self = this;
+  var concurrency = 3;
+  var pendingFiles = files.filter((file) => file.status === "pending");
+  if (pendingFiles.length === 0) return;
+
+  var total = pendingFiles.length;
+  var taskId = this.startTask({
+    title: this.language.batchUpload || "批量上传",
+    total: total
+  });
+
+  var successCount = 0;
+  var failCount = 0;
+  var index = 0;
+
+  var uploadOne = async function () {
+    while (index < pendingFiles.length) {
+      var file = pendingFiles[index++];
+      self.updateFileStatus(file._id, "uploading");
+
+      try {
+        var uploadedFile = await self.internalUpload(file);
+        successCount++;
+        self.updateFileStatus(file._id, "uploaded", uploadedFile);
+        if (typeof self.options.onUploadSuccess === "function") {
+          self.options.onUploadSuccess(uploadedFile);
+        }
+      } catch (error) {
+        failCount++;
+        self.updateFileStatus(file._id, "failed");
+        if (typeof self.options.onUploadError === "function") {
+          self.options.onUploadError(file, error);
+        }
+      }
+
+      self.updateTask({
+        id: taskId,
+        current: successCount + failCount,
+        currentItem: file.name
+      });
+    }
+  };
+
+  Promise.all(Array.from({ length: concurrency }, uploadOne)).then(function () {
+    self.finishTask({ id: taskId, total: total, success: successCount, failed: failCount });
+    if (typeof self.options.onUploadComplete === "function") {
+      self.options.onUploadComplete(successCount, failCount);
+    }
+  });
+}
+```
+
+**修改点**：
+- `handleUpload` 方法重写，实现并发控制
+
+---
+
+### 6. ObjectURL 生命周期管理
+
+**问题**：组件销毁时未释放 ObjectURL
+
+**解决方案**：`destroy` 方法中统一释放
+
+```javascript
+destroy: function () {
+  // 清理事件
+  this.$container.off();
+  $(document).off(".g3file");
+
+  // 清理 ObjectURL
+  this.objectUrls.forEach(function (url) {
+    try {
+      URL.revokeObjectURL(url);
+    } catch (e) {
+      console.warn("释放ObjectURL失败:", e);
+    }
+  });
+  this.objectUrls.clear();
+
+  // 清理文件列表 DOM
+  this.$fileList.empty();
+
+  // 销毁 UI
+  this.$container.find(".g3-global-menu").remove();
+  this.$container.find(".g3-toast-container").remove();
+  this.$container.find(".g3-task-center").remove();
+  this.$container.find(".g3-ui-lock").remove();
+
+  // 重置状态
+  this.files = [];
+  this.selectedFiles.clear();
+  this.tasks.clear();
+  this.currentPreviewFileId = null;
+
+  console.log("G3File 组件已销毁");
+}
+```
+
+---
+
+### 7. 权限系统统一入口
+
+**问题**：globalPermission 和 filePermissionResolver 分散使用
+
+**解决方案**：新增 `resolvePermission(file, action)` 统一方法
+
+```javascript
+resolvePermission: function (file, action) {
+  var globalPermission = this.options.globalPermission;
+  var filePermissionResolver = this.options.filePermissionResolver;
+
+  if (typeof filePermissionResolver === "function") {
+    var result = filePermissionResolver({ file: file, action: action });
+    if (result !== undefined) return !!result;
+  }
+
+  if (typeof globalPermission === "function") {
+    return !!globalPermission({ file: file, action: action });
+  } else if (typeof globalPermission === "object") {
+    return !!globalPermission[action];
+  }
+
+  return true;
+}
+```
+
+**修改点**：
+- `hasPermission` 重命名为 `resolvePermission` 或新增方法，原方法保留为别名
+- 所有调用 `hasPermission` 的地方改为调用 `resolvePermission`
+
+---
+
+## 三、P2 UI/交互修复
+
+### 8. 点击文件项行为优化
+
+**问题**：点击整个 file-item 会触发预览，容易误触
+
+**解决方案**：改为双击触发预览
+
+```javascript
+this.$fileList.on("dblclick", ".g3-file-item", function (e) {
+  if ($(e.target).closest(".g3-file-action, .g3-file-checkbox, .g3-file-delete-btn").length) {
+    return;
+  }
+  var id = $(this).data("id");
+  var file = self.getFileById(id);
+  if (!file) return;
+  self.setPreviewFile(id);
+  if (typeof self.options.onPreview === "function") {
+    self.options.onPreview([file]);
+  }
+});
+```
+
+**修改点**：
+- `bindEvents` 中的 `.g3-file-item` 点击事件改为双击
+
+---
+
+### 9. UI 锁机制完善
+
+**解决方案**：在关键操作开始时检查锁状态
+
+```javascript
+handleUpload: function (files) {
+  if (this.uiLocked) {
+    console.warn("UI is locked, please wait...");
+    return;
+  }
+  // ... 原有逻辑
+}
+
+internalDelete: function (files) {
+  if (this.uiLocked) {
+    console.warn("UI is locked, please wait...");
+    return;
+  }
+  // ... 原有逻辑
+}
+```
+
+---
+
+### 10. 批量删除安全控制
+
+**解决方案**：增加 confirm 回调支持
+
+```javascript
+internalDelete: function (files) {
+  var self = this;
+
+  if (typeof this.options.onBeforeDelete === "function") {
+    var result = this.options.onBeforeDelete(files);
+    if (result === false) return;
+    if (typeof result === "function") {
+      // 异步确认
+      result(function (confirmed) {
+        if (confirmed) self.doDelete(files);
+      });
+      return;
+    }
+  }
+  self.doDelete(files);
+}
+
+doDelete: function (files) {
+  // 原 internalDelete 逻辑
+}
+```
+
+**修改点**：
+- 新增 `onBeforeDelete` 回调选项
+- 重构删除逻辑
+
+---
+
+## 四、CSS 优化
+
+### 11. 文件列表布局优化
+
+**问题**：使用 calc 写死宽度
+
+**解决方案**：改为 flex: calc(50% - 26px) 或 grid
+
+```css
+.g3-main {
+  display: flex;
+  flex-wrap: wrap;
+  align-content: flex-start;
+}
+
+.g3-file-item {
+  flex: 0 0 calc(50% - 20px);
+  max-width: calc(50% - 20px);
+}
+```
+
+---
+
+### 12. z-index 规范化
+
+**解决方案**：建立层级规范
+
+```css
+:root {
+  --g3-z-dropdown: 100;
+  --g3-z-modal: 200;
+  --g3-z-toast: 300;
+  --g3-z-task: 400;
+  --g3-z-lock: 500;
+}
+```
+
+---
+
+## 五、实施步骤
+
+1. **P0-1**: 新增 `updateFileItem()` 方法，修改 `updateFileStatus()`
+2. **P0-2**: 替换 `previewIndex` 为 `currentPreviewFileId`
+3. **P0-3**: 重构 Task Center 为多任务模型
+4. **P1-4**: 事件委托优化
+5. **P1-5**: 上传并发控制
+6. **P1-6**: 完善 `destroy()` 方法
+7. **P1-7**: 新增 `resolvePermission()` 方法
+8. **P2-8**: 双击预览
+9. **P2-9**: UI 锁检查
+10. **P2-10**: 删除确认回调
+11. **CSS**: 布局优化和 z-index 规范化
diff --git a/code/file-preview/g3-file/index.css b/code/file-preview/g3-file/index.css
index 74ea21ab..aa6278ff 100644
--- a/code/file-preview/g3-file/index.css
+++ b/code/file-preview/g3-file/index.css
@@ -5,6 +5,11 @@
   overflow: hidden;
   border: 1px solid #eef0f2;
   border-radius: 8px;
+  --g3-z-dropdown: 100;
+  --g3-z-modal: 200;
+  --g3-z-toast: 300;
+  --g3-z-task: 400;
+  --g3-z-lock: 500;
 }
 
 .g3-file-container.drag-over {
@@ -32,15 +37,13 @@
 .g3-main {
   flex: 1;
   min-height: 0;
-  padding: 4px 0px;
+  padding: 10px;
   overflow: auto;
-  display: flex;
-  flex-wrap: wrap;
+  display: grid;
+  grid-template-columns: repeat(2, 1fr);
+  gap: 10px;
   align-content: flex-start;
-}
-
-.g3-main > * {
-  margin: 10px;
+  box-sizing: border-box;
 }
 
 .g3-empty-tip {
@@ -143,13 +146,15 @@
 }
 
 .g3-file-item {
-  width: calc(50% - 26px);
+  flex: none;
+  width: 100%;
   position: relative;
   cursor: pointer;
   border: 1px solid #eef0f2;
   border-radius: 8px;
   background: #fff;
   box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
+  box-sizing: border-box;
 }
 
 .g3-file-item:hover {
@@ -379,7 +384,7 @@
   align-items: center;
   justify-content: center;
   cursor: pointer;
-  z-index: 100;
+  z-index: var(--g3-z-dropdown);
   font-size: 12px;
   border: 1px solid #e8e8e8;
   transition: all 0.2s ease;
@@ -537,7 +542,7 @@
 
 .g3-global-menu {
   position: fixed;
-  z-index: 9999;
+  z-index: var(--g3-z-dropdown);
   width: 160px;
   background: #fff;
   border: 1px solid #eee;
@@ -578,7 +583,7 @@
   position: fixed;
   top: 20px;
   right: 20px;
-  z-index: 9999;
+  z-index: var(--g3-z-toast);
   display: flex;
   flex-direction: column;
   gap: 12px;
@@ -734,7 +739,7 @@
   border: 1px solid #eef0f2;
   border-radius: 8px;
   box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
-  z-index: 9999;
+  z-index: var(--g3-z-task);
   display: none;
   animation: taskCenterSlideIn 0.3s ease-out;
 }
@@ -857,23 +862,6 @@
   color: #ff4d4f;
 }
 
-.g3-complete-button {
-  width: 100%;
-  margin-top: 12px;
-  padding: 8px;
-  border: none;
-  background: #165dff;
-  color: #fff;
-  font-size: 13px;
-  border-radius: 4px;
-  cursor: pointer;
-  transition: all 0.2s ease;
-}
-
-.g3-complete-button:hover {
-  filter: brightness(1.1);
-}
-
 .g3-ui-lock {
   position: fixed;
   top: 0;
@@ -881,7 +869,7 @@
   right: 0;
   bottom: 0;
   background: rgba(0, 0, 0, 0.05);
-  z-index: 9998;
+  z-index: var(--g3-z-lock);
   display: none;
 }
 
diff --git a/code/file-preview/g3-file/index.js b/code/file-preview/g3-file/index.js
index cbf47bed..2f9ab38e 100644
--- a/code/file-preview/g3-file/index.js
+++ b/code/file-preview/g3-file/index.js
@@ -9,6 +9,7 @@
     this.$container = $(container);
     this.options = $.extend({}, this.defaults, options);
     this.instanceId = G3FileUtils.generateUniqueId();
+    this.documentNamespace = ".g3file_" + this.instanceId;
     this.files = [];
     this.selectedFiles = new Set();
     this.objectUrls = new Map();
@@ -24,7 +25,7 @@
     };
 
     // 当前任务（单个任务实例）
-    this.currentTask = null;
+    this.tasks = new Map();
 
     // UI锁定状态
     this.uiLocked = false;
@@ -32,8 +33,8 @@
     // 阿里云 OSS 凭证缓存
     this.aliyunKeyCache = null;
 
-    // 预览相关状态
-    this.previewIndex = 0;
+    // 预览相关状态（基于 fileId 定位，避免删除/新增导致错位）
+    this.currentPreviewFileId = null;
 
     this.init();
   }
@@ -64,6 +65,7 @@
        */
       data: [],
       mode: "aliyun",
+      onBeforeDelete: null,
       onDelete: null,
       onDownload: null,
       onSelect: null,
@@ -205,14 +207,6 @@
     // 工具方法
     // ============================================================================
 
-    /**
-     * 生成唯一ID
-     * @returns {string} 唯一ID
-     */
-    generateUniqueId: function () {
-      return "file_" + Math.random().toString(36).slice(2) + Date.now();
-    },
-
     /**
      * 获取文件图标
      * @param {string} filename - 文件名
@@ -558,7 +552,6 @@
       });
 
       this.$fileList.html(html);
-      this.bindFileItemEvents();
     },
 
     /**
@@ -620,11 +613,52 @@
       });
     },
 
+    updateFileItem: function (fileId) {
+      var file = this.getFileById(fileId);
+      var $item = this.$fileList.find(`.g3-file-item[data-id="${fileId}"]`);
+      if (!file || !$item.length) return;
+
+      $item
+        .find(".g3-file-checkbox")
+        .prop("checked", this.selectedFiles.has(fileId));
+
+      var $badge = $item.find(".g3-status-badge");
+      if (file.status === "pending") {
+        $badge
+          .attr("class", "g3-status-badge g3-status-pending")
+          .text(this.language.pending)
+          .show();
+      } else if (file.status === "uploading") {
+        $badge
+          .attr("class", "g3-status-badge g3-status-uploading")
+          .text(this.language.uploading)
+          .show();
+      } else if (file.status === "failed") {
+        $badge
+          .attr("class", "g3-status-badge g3-status-failed")
+          .text(this.language.uploadFailed)
+          .show();
+      } else if (file.status === "uploaded") {
+        $badge.attr("class", "g3-status-badge g3-status-uploaded").hide();
+      }
+
+      var canDownload = this.hasPermission(file, "download");
+      var canView = this.hasPermission(file, "view");
+      var canDelete = this.hasPermission(file, "delete");
+      $item
+        .find(".g3-action-download")
+        .toggleClass("is-disabled", !canDownload);
+      $item.find(".g3-action-preview").toggleClass("is-disabled", !canView);
+      $item.find(".g3-file-delete-btn").toggleClass("is-disabled", !canDelete);
+    },
+
     /**
      * 获取已上传的文件列表（仅status为uploaded的文件）
      */
     getUploadedFiles: function () {
-      return this.files;
+      return this.files.filter(function (file) {
+        return file.status === "uploaded";
+      });
     },
 
     isPreviewableFile: function (fileName) {
@@ -658,47 +692,34 @@
       return !nonPreviewableExts.includes(ext);
     },
 
-    /**
-     * 预览上一个文件
-     */
+    getPreviewFileIndex: function (fileId) {
+      var uploadedFiles = this.getUploadedFiles();
+      return uploadedFiles.findIndex(function (f) {
+        return f._id === fileId;
+      });
+    },
+
     previewPrev: function () {
       var uploadedFiles = this.getUploadedFiles();
       if (uploadedFiles.length === 0) return;
 
-      if (this.previewIndex > 0) {
-        this.previewIndex--;
-      } else {
-        this.previewIndex = uploadedFiles.length - 1;
-      }
-
+      var currentIndex = this.getPreviewFileIndex(this.currentPreviewFileId);
+      var newIndex =
+        currentIndex > 0 ? currentIndex - 1 : uploadedFiles.length - 1;
+      this.currentPreviewFileId = uploadedFiles[newIndex]._id;
       this.updatePreview();
     },
 
-    /**
-     * 预览下一个文件
-     */
     previewNext: function () {
       var uploadedFiles = this.getUploadedFiles();
       if (uploadedFiles.length === 0) return;
 
-      if (this.previewIndex < uploadedFiles.length - 1) {
-        this.previewIndex++;
-      } else {
-        this.previewIndex = 0;
-      }
-
+      var currentIndex = this.getPreviewFileIndex(this.currentPreviewFileId);
+      var newIndex =
+        currentIndex < uploadedFiles.length - 1 ? currentIndex + 1 : 0;
+      this.currentPreviewFileId = uploadedFiles[newIndex]._id;
       this.updatePreview();
     },
-    base64Encode: function (str) {
-      return btoa(
-        encodeURIComponent(str).replace(
-          /%([0-9A-F]{2})/g,
-          function (match, p1) {
-            return String.fromCharCode("0x" + p1);
-          },
-        ),
-      );
-    },
     /**
      * 更新预览区域显示
      */
@@ -716,28 +737,35 @@
         this.$previewCounter.text("0/0");
         this.$btnPrev.prop("disabled", true);
         this.$btnNext.prop("disabled", true);
+        this.currentPreviewFileId = null;
         return;
       }
 
-      if (this.previewIndex >= total) {
-        this.previewIndex = total - 1;
-      }
-      if (this.previewIndex < 0) {
-        this.previewIndex = 0;
+      if (
+        !this.currentPreviewFileId ||
+        !this.getFileById(this.currentPreviewFileId)
+      ) {
+        this.currentPreviewFileId = allFiles[0]._id;
       }
 
-      var currentFile = allFiles[this.previewIndex];
+      var currentFile = this.getFileById(this.currentPreviewFileId);
+      if (!currentFile) {
+        this.currentPreviewFileId = allFiles[0]._id;
+        currentFile = allFiles[0];
+      }
+
+      var currentIndex = this.getPreviewFileIndex(this.currentPreviewFileId);
       var isUploaded = currentFile.status === "uploaded";
       var isPreviewable = this.isPreviewableFile(currentFile.name);
       var fileUrl =
         currentFile.url && currentFile.url !== "" ? currentFile.url : null;
 
-      this.$btnPrev.prop("disabled", this.previewIndex === 0);
-      this.$btnNext.prop("disabled", this.previewIndex === total - 1);
+      this.$btnPrev.prop("disabled", currentIndex === 0);
+      this.$btnNext.prop("disabled", currentIndex === total - 1);
 
       this.$previewName.text(currentFile.name);
       var counterText = this.language.previewCount
-        .replace("{current}", this.previewIndex + 1)
+        .replace("{current}", currentIndex + 1)
         .replace("{total}", total);
       this.$previewCounter.text(counterText);
 
@@ -776,18 +804,10 @@
       this.$previewContent.html(previewContent);
     },
 
-    isPreviewContentChanged: function (newContent) {
-      var currentContent = this.$previewContent.html();
-      return currentContent !== newContent;
-    },
-
     setPreviewFile: function (fileId) {
-      var uploadedFiles = this.getUploadedFiles();
-      var index = uploadedFiles.findIndex(function (f) {
-        return f._id === fileId;
-      });
-      if (index >= 0) {
-        this.previewIndex = index;
+      var file = this.getFileById(fileId);
+      if (file) {
+        this.currentPreviewFileId = fileId;
         this.updatePreview();
       }
     },
@@ -801,6 +821,9 @@
      */
     bindEvents: function () {
       var self = this;
+      var documentActionMenuEvent =
+        "click.g3file_actionmenu_" + this.instanceId;
+      var documentPasteEvent = "paste" + this.documentNamespace;
 
       // 选择全部
       this.$checkAll.off("change").on("change", function () {
@@ -819,6 +842,7 @@
 
       // 批量下载
       this.$btnDownload.off("click").on("click", function () {
+        if (!self.hasPermission(null, "download")) return;
         var selectedFiles = self.getSelectedFiles();
         if (selectedFiles.length === 0) return;
 
@@ -827,6 +851,7 @@
 
       // 批量删除
       this.$btnDelete.off("click").on("click", function () {
+        if (!self.hasPermission(null, "delete")) return;
         var selectedFiles = self.getSelectedFiles();
         if (selectedFiles.length === 0) return;
 
@@ -835,11 +860,13 @@
 
       // 选择文件
       this.$btnSelect.off("click").on("click", function () {
+        if (!self.hasPermission(null, "select")) return;
         self.$fileInput.click();
       });
 
       // 上传
       this.$btnUpload.off("click").on("click", function () {
+        if (!self.hasPermission(null, "upload")) return;
         var pendingFiles = self.files.filter(
           (file) => file.status === "pending",
         );
@@ -864,8 +891,8 @@
 
       // 点击其他地方关闭菜单
       $(document)
-        .off("click.g3file_actionmenu")
-        .on("click.g3file_actionmenu", function (e) {
+        .off(documentActionMenuEvent)
+        .on(documentActionMenuEvent, function (e) {
           if (
             !$(e.target).closest(".g3-action-more").length &&
             !$(e.target).closest(".g3-global-menu").length
@@ -909,8 +936,8 @@
 
       // 粘贴文件
       $(document)
-        .off("paste.g3file")
-        .on("paste.g3file", function (e) {
+        .off(documentPasteEvent)
+        .on(documentPasteEvent, function (e) {
           var clipboardData = e.originalEvent.clipboardData;
           var files = clipboardData.files;
           if (files && files.length > 0) {
@@ -928,81 +955,53 @@
       this.$btnNext.off("click").on("click", function () {
         self.previewNext();
       });
-    },
 
-    /**
-     * 绑定文件项事件
-     */
-    bindFileItemEvents: function () {
-      var self = this;
-
-      // 预览
+      // 文件列表事件委托（只在 init 时绑定一次）
       this.$fileList
-        .off("click", ".g3-action-preview")
+        // 预览按钮
         .on("click", ".g3-action-preview", function (e) {
           e.preventDefault();
           e.stopPropagation();
-
           var id = $(this).closest(".g3-file-item").data("id");
-          var file = self.files.find((f) => f._id === id);
-
+          var file = self.getFileById(id);
           if (!file) return;
-
+          if (!self.hasPermission(file, "view")) return;
           self.setPreviewFile(id);
-
           if (typeof self.options.onPreview === "function") {
             self.options.onPreview([file]);
           }
-        });
-
-      // 下载
-      this.$fileList
-        .off("click", ".g3-action-download")
+        })
+        // 下载按钮
         .on("click", ".g3-action-download", function (e) {
           e.preventDefault();
           e.stopPropagation();
-
           var id = $(this).closest(".g3-file-item").data("id");
-          var file = self.files.find((f) => f._id === id);
-
+          var file = self.getFileById(id);
           if (!file) return;
-
+          if (!self.hasPermission(file, "download")) return;
           self.handleDownload([file], { batch: false });
-        });
-
-      // 复选框
-      this.$fileList
-        .off("change", ".g3-file-checkbox")
+        })
+        // 复选框
         .on("change", ".g3-file-checkbox", function () {
           var id = $(this).closest(".g3-file-item").data("id");
-
           if ($(this).is(":checked")) {
             self.selectedFiles.add(id);
           } else {
             self.selectedFiles.delete(id);
           }
-
           self.updateUI();
-        });
-
-      // 删除
-      this.$fileList
-        .off("click", ".g3-file-delete-btn")
+        })
+        // 删除按钮
         .on("click", ".g3-file-delete-btn", function (e) {
           e.preventDefault();
           e.stopPropagation();
-
           var id = $(this).closest(".g3-file-item").data("id");
-          var file = self.files.find((f) => f._id === id);
-
+          var file = self.getFileById(id);
           if (!file) return;
-
+          if (!self.hasPermission(file, "delete")) return;
           self.handleDelete([file]);
-        });
-
-      // 文件项点击
-      this.$fileList
-        .off("click", ".g3-file-item")
+        })
+        // 文件项单击预览
         .on("click", ".g3-file-item", function (e) {
           if (
             $(e.target).closest(
@@ -1011,32 +1010,23 @@
           ) {
             return;
           }
-
           var id = $(this).data("id");
-          var file = self.files.find((f) => f._id === id);
-
+          var file = self.getFileById(id);
           if (!file) return;
-
+          if (!self.hasPermission(file, "view")) return;
           if (typeof self.options.onPreview === "function") {
             self.options.onPreview([file]);
           }
-
           self.setPreviewFile(id);
-        });
-
-      // 更多按钮
-      this.$fileList
-        .off("click", ".g3-action-more")
+        })
+        // 更多按钮
         .on("click", ".g3-action-more", function (e) {
           e.preventDefault();
           e.stopPropagation();
-
           var $el = $(this).closest(".g3-file-action");
           var id = $el.closest(".g3-file-item").data("id");
           var file = self.getFileById(id);
-
           if (!file) return;
-
           if (
             self.actionMenuState.open &&
             self.actionMenuState.fileId === file._id
@@ -1044,9 +1034,16 @@
             self.closeActionMenu();
             return;
           }
-
           self.openActionMenu($el, file);
         });
+
+      // 任务关闭按钮事件委托
+      this.$container.on("click", ".g3-task-close", function (e) {
+        e.preventDefault();
+        e.stopPropagation();
+        var taskId = $(this).closest(".g3-task-center").data("task-id");
+        self.closeTask(taskId);
+      });
     },
 
     // ============================================================================
@@ -1156,7 +1153,27 @@
     handleDelete: function (files) {
       var self = this;
 
-      if (typeof this.options.onDelete === "function") {
+      if (this.uiLocked) {
+        console.warn("UI is locked, please wait...");
+        return;
+      }
+
+      if (typeof this.options.onBeforeDelete === "function") {
+        var result = this.options.onBeforeDelete(files);
+        if (result === false) return;
+        if (typeof result.then === "function") {
+          result.then(function (confirmed) {
+            if (confirmed) self.internalDelete(files);
+          });
+          return;
+        }
+        if (typeof result === "function") {
+          result(function (confirmed) {
+            if (confirmed) self.internalDelete(files);
+          });
+          return;
+        }
+      } else if (typeof this.options.onDelete === "function") {
         this.options.onDelete(files, function (success) {
           if (success) {
             self.internalDelete(files);
@@ -1372,8 +1389,7 @@
         if (data) {
           Object.assign(file, data);
         }
-        this.renderFileList();
-        this.updateUI();
+        this.updateFileItem(fileId);
       }
     },
 
@@ -1383,8 +1399,6 @@
      * @param {Function} callback - 上传完成回调
      */
     internalUpload: async function (file, callback) {
-      const self = this;
-
       try {
         const keyData = await this.getValidAliyunKey();
 
@@ -1417,25 +1431,10 @@
           uploadDate: new Date().toISOString(),
         };
 
-        self.updateFileStatus(file._id, "uploaded", {
-          url: uploadedFile.url,
-          uploadDate: uploadedFile.uploadDate,
-        });
-
-        if (typeof self.options.onUploadSuccess === "function") {
-          self.options.onUploadSuccess(uploadedFile);
-        }
-
         callback(null, uploadedFile);
       } catch (error) {
         console.error("[G3File] 上传失败:", error);
 
-        self.updateFileStatus(file._id, "failed");
-
-        if (typeof self.options.onUploadError === "function") {
-          self.options.onUploadError(file, error);
-        }
-
         callback(error);
       }
     },
@@ -1445,117 +1444,111 @@
      * @param {Array} files - 文件数组
      */
     handleUpload: function (files) {
-      const self = this;
-      const customUpload = this.options.uploadConfig.customUpload;
-      let successCount = 0;
-      let failCount = 0;
+      var self = this;
 
-      // 过滤出未上传的文件
-      const pendingFiles = files.filter((file) => file.status === "pending");
+      if (this.uiLocked) {
+        console.warn("UI is locked, please wait...");
+        return;
+      }
+
+      var customUpload = this.options.uploadConfig.customUpload;
+      var concurrency = 3;
+      var pendingFiles = files.filter(function (file) {
+        return file.status === "pending";
+      });
 
       if (pendingFiles.length === 0) {
-        // 触发上传完成回调
         if (typeof self.options.onUploadComplete === "function") {
           self.options.onUploadComplete(0, 0);
         }
         return;
       }
 
-      const total = pendingFiles.length;
-      const taskId = G3FileUtils.generateUniqueId();
-
-      // 启动上传任务
-      this.startTask({
-        id: taskId,
+      var total = pendingFiles.length;
+      var taskId = this.startTask({
+        id: G3FileUtils.generateUniqueId(),
         title: this.language.batchUpload || "批量上传",
         total: total,
         current: 0,
         currentItem: "",
       });
 
-      // 逐个上传文件
-      pendingFiles.forEach((file) => {
-        // 更新文件状态为上传中
+      var successCount = 0;
+      var failCount = 0;
+      var completedCount = 0;
+      var index = 0;
+
+      function uploadNext() {
+        if (index >= pendingFiles.length) return Promise.resolve();
+
+        var file = pendingFiles[index++];
         self.updateFileStatus(file._id, "uploading");
 
-        if (typeof customUpload === "function") {
-          // 使用自定义上传方法
-          customUpload(file)
-            .then((uploadedFile) => {
-              // 更新任务进度
-              self.updateTask({
-                id: taskId,
-                current: successCount + failCount,
-                currentItem: file.name,
-              });
-
-              // 更新文件状态
-              self.updateFileStatus(file._id, "uploaded", uploadedFile);
-
-              // 触发上传成功回调
-              if (typeof self.options.onUploadSuccess === "function") {
-                self.options.onUploadSuccess(uploadedFile);
-              }
-
-              successCount++;
-              checkComplete();
-            })
-            .catch((error) => {
-              // 更新任务进度
-              self.updateTask({
-                id: taskId,
-                current: successCount + failCount,
-                currentItem: file.name,
-              });
-
-              // 更新文件状态为失败
-              self.updateFileStatus(file._id, "failed");
-
-              // 触发上传失败回调
-              if (typeof self.options.onUploadError === "function") {
-                self.options.onUploadError(file, error);
-              }
-
-              failCount++;
-              checkComplete();
-            });
-        } else if (this.options.mode === "aliyun") {
-          // 使用阿里云内部上传方法
-          self.internalUpload(file, (error, uploadedFile) => {
-            // 更新任务进度
-            self.updateTask({
-              id: taskId,
-              current: successCount + failCount,
-              currentItem: file.name,
-            });
+        return new Promise(function (resolve) {
+          function handleResult(error, uploadedFile) {
+            completedCount++;
 
             if (error) {
               failCount++;
+              self.updateFileStatus(file._id, "failed");
+              if (typeof self.options.onUploadError === "function") {
+                self.options.onUploadError(file, error);
+              }
             } else {
               successCount++;
+              self.updateFileStatus(file._id, "uploaded", uploadedFile);
+              if (typeof self.options.onUploadSuccess === "function") {
+                self.options.onUploadSuccess(uploadedFile);
+              }
             }
-            checkComplete();
-          });
-        }
-      });
 
-      // 检查是否所有文件都上传完成
-      function checkComplete() {
-        if (successCount + failCount === pendingFiles.length) {
-          // 完成任务
-          self.finishTask({
-            id: taskId,
-            total: total,
-            success: successCount,
-            failed: failCount,
-          });
+            self.updateTask({
+              id: taskId,
+              current: completedCount,
+              currentItem: file.name,
+            });
 
-          // 触发上传完成回调
-          if (typeof self.options.onUploadComplete === "function") {
-            self.options.onUploadComplete(successCount, failCount);
+            if (completedCount === total) {
+              self.finishTask({
+                id: taskId,
+                total: total,
+                success: successCount,
+                failed: failCount,
+              });
+              if (typeof self.options.onUploadComplete === "function") {
+                self.options.onUploadComplete(successCount, failCount);
+              }
+            }
+
+            resolve();
           }
-        }
+
+          if (typeof customUpload === "function") {
+            customUpload(file)
+              .then(function (uploadedFile) {
+                handleResult(null, uploadedFile);
+              })
+              .catch(function (error) {
+                handleResult(error, null);
+              });
+          } else if (self.options.mode === "aliyun") {
+            self.internalUpload(file, function (error, uploadedFile) {
+              handleResult(error, uploadedFile);
+            });
+          } else {
+            handleResult(new Error("No upload method configured"), null);
+          }
+        }).then(function () {
+          return uploadNext();
+        });
       }
+
+      var runners = [];
+      for (var i = 0; i < concurrency && i < pendingFiles.length; i++) {
+        runners.push(uploadNext());
+      }
+
+      Promise.all(runners);
     },
 
     // ============================================================================
@@ -1654,21 +1647,20 @@
      * @param {string} options.currentItem - 当前处理项
      */
     startTask: function (options) {
-      const { id, title, total = 0, current = 0, currentItem = "" } = options;
-
-      this.currentTask = {
-        id: id || G3FileUtils.generateUniqueId(),
-        title: title,
-        total: total,
-        current: current,
-        currentItem: currentItem,
+      var task = {
+        id: options.id || G3FileUtils.generateUniqueId(),
+        title: options.title,
+        total: options.total || 0,
+        current: options.current || 0,
+        currentItem: options.currentItem || "",
         success: 0,
         failed: 0,
         status: "running",
       };
-
+      this.tasks.set(task.id, task);
       this.lockUI();
-      this.renderTaskCenter();
+      this.renderTaskCenter(task.id);
+      return task.id;
     },
 
     /**
@@ -1679,20 +1671,12 @@
      * @param {string} options.currentItem - 当前处理项
      */
     updateTask: function (options) {
-      const { id, current, currentItem } = options;
-
-      if (!this.currentTask || this.currentTask.id !== id) {
-        return;
-      }
-
-      if (current !== undefined) {
-        this.currentTask.current = current;
-      }
-      if (currentItem !== undefined) {
-        this.currentTask.currentItem = currentItem;
-      }
-
-      this.updateTaskCenter();
+      var task = this.tasks.get(options.id);
+      if (!task) return;
+      if (options.current !== undefined) task.current = options.current;
+      if (options.currentItem !== undefined)
+        task.currentItem = options.currentItem;
+      this.updateTaskCenter(options.id);
     },
 
     /**
@@ -1704,21 +1688,18 @@
      * @param {number} options.failed - 失败数量
      */
     finishTask: function (options) {
-      const { id, total, success = 0, failed = 0 } = options;
-
-      if (!this.currentTask || this.currentTask.id !== id) {
-        return;
+      var task = this.tasks.get(options.id);
+      if (!task) return;
+      task.status = "finished";
+      task.total = options.total !== undefined ? options.total : task.total;
+      task.success = options.success || 0;
+      task.failed = options.failed || 0;
+      task.current = task.total;
+      this.updateTaskCenter(options.id);
+      this.tasks.delete(options.id);
+      if (this.tasks.size === 0) {
+        this.unlockUI();
       }
-
-      this.currentTask.status = "finished";
-      this.currentTask.total =
-        total !== undefined ? total : this.currentTask.total;
-      this.currentTask.success = success;
-      this.currentTask.failed = failed;
-      this.currentTask.current = this.currentTask.total;
-
-      this.unlockUI();
-      this.updateTaskCenter();
     },
 
     /**
@@ -1726,23 +1707,33 @@
      * @param {string} id - 任务ID
      */
     closeTask: function (id) {
-      if (this.currentTask && this.currentTask.id === id) {
-        this.$taskCenter.removeClass("is-visible");
-        this.currentTask = null;
+      var task = this.tasks.get(id);
+      if (task) {
+        task.status = "closed";
+        this.tasks.delete(id);
+      }
+
+      var taskCenter = this.$container.find(
+        `.g3-task-center[data-task-id="${id}"]`,
+      );
+      if (taskCenter.length) {
+        taskCenter.remove();
+      }
+      this.$taskCenter = null;
+
+      if (this.tasks.size === 0) {
+        this.unlockUI();
       }
     },
 
-    /**
-     * 渲染任务中心 UI
-     */
-    renderTaskCenter: function () {
-      const task = this.currentTask;
+    renderTaskCenter: function (taskId) {
+      var task = this.tasks.get(taskId);
       if (!task) return;
 
       let taskCenter = this.$container.find(".g3-task-center");
       if (!taskCenter.length) {
         this.$container.append(`
-          <div class="g3-task-center">
+          <div class="g3-task-center" data-task-id="${taskId}">
             <div class="g3-task-header">
               <span class="g3-task-title">${task.title}</span>
               <button class="g3-task-close">&times;</button>
@@ -1767,31 +1758,19 @@
                   <div class="g3-result-label">${this.language.task.failed}</div>
                 </div>
               </div>
-              <button class="g3-complete-button" style="display: none;">${this.language.task.close}</button>
             </div>
           </div>
         `);
         taskCenter = this.$container.find(".g3-task-center");
-
-        const self = this;
-        taskCenter
-          .find(".task-close, .complete-button")
-          .off("click")
-          .on("click", function () {
-            self.closeTask(self.currentTask?.id);
-          });
       }
 
       this.$taskCenter = taskCenter;
       this.$taskCenter.addClass("is-visible");
-      this.updateTaskCenter();
+      this.updateTaskCenter(taskId);
     },
 
-    /**
-     * 更新任务中心 UI
-     */
-    updateTaskCenter: function () {
-      const task = this.currentTask;
+    updateTaskCenter: function (taskId) {
+      var task = this.tasks.get(taskId);
       if (!task || !this.$taskCenter) return;
 
       const progress =
@@ -1812,7 +1791,6 @@
 
       if (task.status === "finished") {
         this.$taskCenter.find(".g3-result-section").show();
-        this.$taskCenter.find(".g3-complete-button").show();
         this.$taskCenter
           .find(".g3-result-item:first .g3-result-value")
           .text(task.total);
@@ -1824,7 +1802,6 @@
           .text(task.failed);
       } else {
         this.$taskCenter.find(".g3-result-section").hide();
-        this.$taskCenter.find(".g3-complete-button").hide();
       }
     },
 
@@ -1902,10 +1879,13 @@
      * @returns {boolean} 是否有权限
      */
     hasPermission: function (file, action) {
+      return this.resolvePermission(file, action);
+    },
+
+    resolvePermission: function (file, action) {
       var globalPermission = this.options.globalPermission;
       var filePermissionResolver = this.options.filePermissionResolver;
 
-      // 1. 优先判断单文件权限解析函数
       if (typeof filePermissionResolver === "function") {
         var fileResult = filePermissionResolver({ file: file, action: action });
         if (fileResult !== undefined) {
@@ -1913,14 +1893,12 @@
         }
       }
 
-      // 2. 判断全局权限
       if (typeof globalPermission === "function") {
         return !!globalPermission({ file: file, action: action });
       } else if (typeof globalPermission === "object") {
         return !!globalPermission[action];
       }
 
-      // 默认返回 true
       return true;
     },
 
@@ -1979,11 +1957,9 @@
      * @returns {G3File} 实例
      */
     setFiles: function (files) {
-      var self = this;
-
       this.files = files.map(function (file) {
         return {
-          _id: file._id || self.generateUniqueId(),
+          _id: file._id || G3FileUtils.generateUniqueId(),
           name: file.name,
           size: file.size,
           uploadDate: file.uploadDate || new Date().toISOString(),
@@ -1995,7 +1971,7 @@
       });
 
       this.selectedFiles.clear();
-      this.previewIndex = 0;
+      this.currentPreviewFileId = null;
       this.renderFileList();
       this.updateUI();
       this.updatePreview();
@@ -2012,10 +1988,11 @@
       if (partialState.files) {
         this.setFiles(partialState.files);
       } else {
-        // 其他状态更新时关闭当前任务
-        if (this.currentTask) {
-          this.closeTask(this.currentTask.id);
-        }
+        // 其他状态更新时关闭所有运行中的任务
+        var self = this;
+        this.tasks.forEach(function (task, taskId) {
+          self.closeTask(taskId);
+        });
       }
 
       if (partialState.selectedFiles) {
@@ -2024,8 +2001,14 @@
       }
 
       if (
-        partialState.globalPermission ||
-        partialState.filePermissionResolver
+        Object.prototype.hasOwnProperty.call(
+          partialState,
+          "globalPermission",
+        ) ||
+        Object.prototype.hasOwnProperty.call(
+          partialState,
+          "filePermissionResolver",
+        )
       ) {
         this.updatePermissions({
           globalPermission: partialState.globalPermission,
@@ -2040,10 +2023,13 @@
      * 销毁
      */
     destroy: function () {
-      this.$container.off();
+      // 清理 document 事件
+      $(document).off(this.documentNamespace);
+      $(document).off(".g3file_actionmenu_" + this.instanceId);
 
-      // 清理ObjectURL
-      this.objectUrls.forEach((url) => {
+      // 清理 ObjectURL
+      var self = this;
+      this.objectUrls.forEach(function (url) {
         try {
           URL.revokeObjectURL(url);
         } catch (e) {
@@ -2052,10 +2038,24 @@
       });
       this.objectUrls.clear();
 
-      // 清理引用
+      // 清理任务
+      this.tasks.forEach(function (task, taskId) {
+        self.closeTask(taskId);
+      });
+
+      // 清理 DOM
+      this.$container.find(".g3-global-menu").remove();
+      this.$container.find(".g3-toast-container").remove();
+      this.$container.find(".g3-task-center").remove();
+      this.$container.find(".g3-ui-lock").remove();
+      this.$container.empty();
+
+      // 重置状态
       this.files = [];
       this.selectedFiles.clear();
-      this.$container.empty();
+      this.tasks.clear();
+      this.currentPreviewFileId = null;
+      this.uiLocked = false;
 
       console.log("G3File 组件已销毁");
     },
@@ -2085,6 +2085,10 @@
       }
     });
 
+    if (typeof options === "string") {
+      return methodResult !== undefined ? methodResult : this;
+    }
+
     return instance || this;
   };
 })(jQuery);