文件上传在FormView控件的UpdatePanel内 [英] FileUpload in FormView inside an UpdatePanel

问题描述

的情景：结果
我有一个ASP.Net网页，我打算用于让用户（不是真正的用户，但内容基本上经理）插入和使用一个FormView在表格编辑记录。这FormView控件是一个UpdatePanel内，因为我还使用级联dropdownlists让用户选择一些值。

The Scenario:
I have an ASP.Net webpage which I intend to use for letting the user(not the real users, but content manager basically) insert and edit the records in a table using a FormView. This FormView is inside an UpdatePanel, as I'm also using cascading dropdownlists to let the user select some values.

现在，这个FormView控件还包含4的FileUpload控件，并且你可能知道，这些文件上传控件需要一个完整的回发，因为大多数浏览器，不要让JavaScript中访问磁盘。所以，这个问题会一直做类似解决：

Now, this FormView also contains 4 FileUpload controls, and as you might know that these fileupload controls require a full postback since most browsers do not let Javascript access the disk. So, this problem would have been solved by doing something like:

<asp:UpdatePanel ID="UpdatePanel1" runat="server">
           <Triggers>
           <asp:PostBackTrigger ControlID="InsertButton" />
           <asp:PostBackTrigger ControlID="UpdateButton" />
           </Triggers>
                    <ContentTemplate>....</ContentTemplate>
</asp:UpdatePanel>

编辑：忘了补充一点，fileuploading发生在代替 OnUpdating 和 OnInserting 在SqlDataSource事件

Forgot to add that the fileuploading takes place in the OnUpdating and OnInserting events of the SqlDataSource.

问题：结果
因为 InsertButton 和 UpdateButton 位于FormView控件里面，我不能直接通过标记访问他们的ID。和MSDN 说说：

The Problem:
Since the InsertButton and the UpdateButton reside inside the Formview, I cannot directly access their ID's through markup. And MSDN says that:

编程添加
  PostBackTrigger控制不
  支持。

Programmatically adding PostBackTrigger controls is not supported.

请提出了一些解决方案，以使这项工作。对此事的任何见解是非常AP preciated。谢谢你。

Please suggest some solution to make this work. Any insight on the matter is highly appreciated. Thanks.

P.S.-我一个可行的解决方案是建立在UpdatePanel的PostBackTrigger作为整个FormView控件本身：

P.S.- A workable solution for me was to set the UpdatePanel's PostBackTrigger as the whole FormView itself:

<asp:UpdatePanel ID="UpdatePanel1" runat="server">
           <Triggers>
           <asp:PostBackTrigger ControlID="FormView1" />
           </Triggers>
                    <ContentTemplate>....</ContentTemplate>
</asp:UpdatePanel>

但现在由于位需求的变化，此解决方案（如果你把它叫做一个解决方案）是不能接受的。

But now due to a bit of change in requirements, this solution(if you call it a solution) is not acceptable.

推荐答案

耶！终于得到它的工作！

Yay!! Finally got it to work!

下面是如何：

好了相反的是MSDN说，我们其实可以添加回发触发器编程。不一定是的UpdatePanel ，但对的ScriptManager 。

Well contrary to what MSDN says, we can in fact add PostBack Triggers Programmatically. Not necessarily to the UpdatePanel, but to the ScriptManager.

后的玩耍时间，这里是什么工作：

After hours of playing around, here's what worked:

我们不能够访问一个FormView内控制，直到该模板已经呈现，所以我们只能添加回发触发后FormView的 OnDataBound 事件。

We are not able to access controls inside a FormView, untill the template has been rendered, so we can only add postback triggers after the formview's OnDataBound Event.

protected void FormView1_DataBound(object sender, EventArgs e)
    {
        if (FormView1.CurrentMode == FormViewMode.Edit)
        {
            LinkButton lb = (LinkButton)FormView1.FindControl("UpdateButton");
            ScriptManager.GetCurrent(Page).RegisterPostBackControl(lb);
        }

        //Similarily you can put register the Insert LinkButton as well.
    }

现在，如果您的UpdatePanel导致 ConditionalUpdate ，你可以做这样的事情，使其工作：

And now, if your UpdatePanel causes ConditionalUpdate, you can do something like this to make it work:

标记：

<asp:UpdatePanel ID="UpdatePanel1" runat="server">
           <ContentTemplate>..
            <EditItemTemplate>
              ...
            <asp:LinkButton ID="UpdateButton" runat="server" CausesValidation="True" OnClick="Cause_PostBack"CommandName="Update">Update</asp:LinkButton>
             ...
            </EditItemTemplate>
           ..</ContentTemplate>
</asp:UpdatePanel>

codeBehind：

CodeBehind:

//call this function as the OnClick Event Handler for the Controls you want to register as
//triggers.
protected void Cause_PostBack()
    {
        UpdatePanel1.Update();
    }

否则，如果条件允许它（如我的一样），只需设置在UpdatePanel的的UpdateMode =始终

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