fix:下载PPT时，取消后，然后再次点击下载失败

src/hooks/useDownLoadFile.js

@@ -13,14 +13,17 @@ import { PDFDocument } from "pdf-lib";
  *  cancelDownload  取消下载
  * }
  */
+
 export function useDownLoadFile() {
   let progress = ref(0); //进度 0-1
   let fileSize = ref(0); //文件大小
-
-  const controller = new AbortController();
-
+  let controller = ''
   // 开始下载
   const startDownload = (url, filename) => {
+    if(controller){
+      controller = null
+    }
+    controller = new AbortController();
     axios({
       url: url,
       method: "get",