Merge pull request #12604 from dataease/pr@dev-v2@fix_event-v3

fix(仪表板、数据大屏): 修复导出事件因仪表板或数据大屏特殊命名导致没有图片文件后缀问题 #12198

core/core-frontend/src/utils/imgUtils.ts

@@ -81,12 +81,9 @@ export function download2AppTemplate(downloadType, canvasDom, name, attachParams
 export function downloadCanvas2(type, canvasDom, name, callBack?) {
   toPng(canvasDom)
     .then(dataUrl => {
-      const a = document.createElement('a')
-      a.setAttribute('download', name)
-      a.href = dataUrl
       if (type === 'img') {
         const a = document.createElement('a')
-        a.setAttribute('download', name)
+        a.setAttribute('download', name + '.png')
         a.href = dataUrl
         document.body.appendChild(a)
         a.click()