AsyncFileUpload回传导致双上传 [英] AsyncFileUpload postback causes double upload

问题描述

我实现了一个网页上的 AsyncFileUpload 控制。此网页需要上传的文件出现在的GridView 。
该的GridView 包含以下栏目：文件名的，保密的复选框，以及删除的按钮来删除上传的文件。

I implemented the AsyncFileUpload control on a web page. This web page requires uploaded files to appear in a GridView.
The GridView contains the following columns: "File Name", "Confidential" Check Box, and a "Remove" button to remove the uploaded file.

由于 AsyncFileUpload 回传没有做的全页的回传，我需要逼回发的 OnClientUploadComplete 事件，以便上传文件后，呈现在GridView的AsyncFileUpload控制。
在 OnClientUploadCompleteEvent ，我使用JavaScript来调用 __ doPostBack 。在这回发，我只能绑定我的GridView和显示文件信息（我不要再保存文件）。

Since the AsyncFileUpload postback does not do a full page postback, I need to "force" a postback on the OnClientUploadComplete event of the AsyncFileUpload control in order to render the gridview after uploading a file.
In the OnClientUploadCompleteEvent, I use javascript to call __doPostBack. In this postback, I only bind my GridView and display the file information (I don’t re-save the file).

问题：在 AsyncFileUpload 第一个局部回传，该文件被上传成功，符合市场预期。在我与强制__ doPostBack 第二回传，该文件重新上传。
您可以通过使用谷歌浏览器，显示上传进度验证这一点。的行为如下：
  - 选择文件后，进度增量从0％到100％，并且该文件被上传
。   - 在此之后， __ doPostBack 执行，你可以再次看到上传进度增量从0％到100％

The problem: On the AsyncFileUpload’s first "partial" postback, the file is successfully uploaded, as expected. On the second postback that I force with __doPostBack, the file is re-uploaded.
You can verify this by using Google Chrome, which displays the upload progress. The behaviour is as follows:
- After selecting the file, the progress increments from 0% to 100% and the file is uploaded.
- After this, the __doPostBack executes, and you can see the upload progress increment again from 0% to 100%.

我怎样才能确保在GridView填充正常，但该文件没有上传过两次？

How can I make sure the Gridview is properly populated, but that the file is not uploaded twice?

我连接包含问题的样品溶液： https://www.yousendit.com/download/ MzZFc2ZBNDRrYUN4dnc9PQ

I attached a sample solution which contains the issue: https://www.yousendit.com/download/MzZFc2ZBNDRrYUN4dnc9PQ

推荐答案

也许难看，但作品：

1） 添加CSS隐藏的asp：按钮娄ASP：AsyncFileUpload AsyncFileUpload1 控制

1) Add a css-hidden asp:Button bellow the asp:AsyncFileUpload AsyncFileUpload1 control.

<asp:Button runat="server" ID="btnClick" Text="Update grid" style="display:none"/>

2） 在的Page_Load 法，删除如果（Request.Params.Get（__ EVENTTARGET）==UploadPostback）并把它挡在一个简单的其他至previous 如果。

2) On the Page_Load method, remove the if (Request.Params.Get("__EVENTTARGET") == "UploadPostback") and put its block in a simple else to the previous if.

3） 在 AsyncFileUpload1_UploadedComplete 功能，还删除如果（Request.Params.Get（__ EVENTTARGET）！=UploadPostback）行，但留下完整的一切，在它里面。

3) On the AsyncFileUpload1_UploadedComplete function, also remove the if (Request.Params.Get("__EVENTTARGET") != "UploadPostback") line, but leave intact everything that was inside it.

4） 回到ASPX。将一个ASP：UpdatePanel中电网GridView1外

4) Back to the aspx. Put a asp:UpdatePanel outside the grid GridView1.

<asp:UpdatePanel runat="server" UpdateMode="Conditional">
     <Triggers>
         <asp:AsyncPostBackTrigger ControlID="btnClick" EventName="Click" />
     </Triggers>
     <ContentTemplate>

     <asp:GridView ID="GridView1" ...
     YOUR GRID CODE REMAINS THE SAME
     </asp:GridView>

    </ContentTemplate>
</asp:UpdatePanel>

5） 最后一步是修改 AjaxUploadComplete 客户端的JavaScript功能，使之触发回发。 用以下替换它：

5) The last step is to change the AjaxUploadComplete client-side javascript function to make it trigger the postback. Replace it with the following:

function AjaxUploadComplete() {
    var btnClick = document.getElementById("btnClick");
    btnClick.click();
}

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用户选择上传一次的任何文件。
所有的变化在这里是为了在AjaxUpload.aspx和放大器来进行;您AjaxUpload.zip的AjaxUpload.aspx.cs。

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Any file the user selects is uploaded only once.
All changes here are meant to be made in AjaxUpload.aspx & AjaxUpload.aspx.cs of your AjaxUpload.zip.

这篇关于AsyncFileUpload回传导致双上传的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！