Upload: create blob URL when picture displays (#12402)

* Upload: create blob URL when picture displays

* Update index.vue

packages/upload/src/index.vue

@@ -146,12 +146,14 @@ export default {
         raw: rawFile
       };
 
+      if (this.listType === 'picture-card' || this.listType === 'picture') {
         try {
           file.url = URL.createObjectURL(rawFile);
         } catch (err) {
-        console.error(err);
+          console.error('[Element Error][Upload]', err);
           return;
         }
+      }
 
       this.uploadFiles.push(file);
       this.onChange(file, this.uploadFiles);
@@ -241,6 +243,14 @@ export default {
     }
   },
 
+  beforeDestroy() {
+    this.uploadFiles.forEach(file => {
+      if (file.url && file.url.indexOf('blob:') === 0) {
+        URL.revokeObjectURL(file.url);
+      }
+    });
+  },
+
   render(h) {
     let uploadList;