Asp.net button onclick not working in updatepanel

Question

My problem is, the asp button's onclick is not working inside the updatepanel. Basically what my code does is, I have an asp fileupload control to upload a file. And then afterwards, the user can now click the button and the filename of the uploaded file will be displayed in the asp label control.

But when i tried it, it is not displaying the filename in the label. It does nothing.

Here is the aspx:

   <asp:UpdatePanel runat="server" UpdateMode="Always" ID="updPnlName" 
    ChildrenAsTriggers="true">
                         <ContentTemplate>
                              <asp:FileUpload runat="server" ID="Image1"/>
                                   <asp:Button ID="Button2" runat="server" 
                                    Text="Upload" OnClick="Button2_Click"/>
                             </ContentTemplate>
                            <Triggers>
                               <asp:AsyncPostBackTrigger ControlID="Button2" 
                                    EventName="Click"/> 
                            </Triggers>
                     </asp:UpdatePanel>
                     <asp:Label ID="Label3" runat="server" Text="Label">
  </asp:Label>

Here is the code-behind:

public void Button2_Click(Object sender, EventArgs e)
{
    var filename1 = Image1.FileName;
    Label3.Text = "Upload successfull - " + filename1;
}

By the way, the reason why i wanted to use updatepanel is to avoid refreshing the entire page when the user clicked the button. Please kindly help me on this one.

Answer 1

将标签放在UpdatePanel内，这将更新标签控件的文本值。