update

js/Desktop/DeskTop.js

@@ -3729,16 +3729,19 @@ U.MD.D.I.openApplicationJie = function (str, cid, stage, task, tool) {
                 U.MD.D.I.getContent(cid, stage, task, tool, _userid, '2', _iframe)
             })
         } else if (str == 'whiteboard') {
-            try {
-                _iframe.onload = () => {
-                    _iframe.contentWindow.document.body.appendChild(script1);
-                    _iframe.contentWindow.document.body.appendChild(script2);
-                    _iframe.contentWindow.document.body.appendChild(script4);
-                    U.MD.D.I.getContent(cid, stage, task, tool, _userid, '3', _iframe)
-                };   
-            } catch (error) {
+            let onloadListener = _iframe.onload = () => {
+                _iframe.contentWindow.document.body.appendChild(script1);
+                _iframe.contentWindow.document.body.appendChild(script2);
+                _iframe.contentWindow.document.body.appendChild(script4);
                 U.MD.D.I.getContent(cid, stage, task, tool, _userid, '3', _iframe)
-            }
+            };   
+            if (onloadListener) {  
+                // iframe 已经加载完成  
+              } else {  
+                // iframe 还没有加载完成  
+                U.MD.D.I.getContent(cid, stage, task, tool, _userid, '3', _iframe)
+              }  
+              
         } else {
             _iframe.onload = () => {
                 _iframe.contentWindow.document.body.appendChild(script1);