Why does asp.net onclick event not change the button text when the button is clicked?_问答_开发者

Why does asp.net onclick event not change the button text when the button is clicked?

开发者 https://www.devze.com 2023-01-15 09:54 出处：网络

Obviously I am a total noob and this is simple to some of you, but I can not figure out why the rest of the sub works, but thebutton1.Text=\"Uploading, Please Wait...\" seems to be completely ignored.

相关专题：asp.net

Obviously I am a total noob and this is simple to some of you, but I can not figure out why the rest of the sub works, but the button1.Text="Uploading, Please Wait..." seems to be completely ignored.

The button is supposed to change text when clicked but no method I have tried works with my page.

Any ideas? Here is my simple upload form page:

<%@ Page aspcompat=true %>

<% ' import all relevant namespaces %>
<%@ import namespace="System" %>
<%@ import namespace="System.Drawing" %>
<%@ import namespace="System.Drawing.Imaging" %>
<%@ import namespace="System.IO" %>

<html>    
<head>

<title>Photo 1 Upload</title>

</head>
<body bgcolor="#000000">

<p>
<table align="center" bgcolor="white" cellpadding="5" cellspacing="2" border="2" width="">
    <tr>
        <td align="center" valign="middle" nowrap bgcolor="554aa1">
            <font face="arial" color="white" size="5">
            <b>Click the "Browse..." button to select your
            <br>photo then click "Upload"</b>
            <p>
            </font>
            <font face="arial" color="white" size="4">
            Note: Image must be .jpg format and less than 4MB
            </font>
        </td>
    </tr>
    <tr>
        <td align="center" valign="middle" bgcolor="#cccccc">

            <form id="form1" runat="server">
            <div>
            <asp:FileUpload ID="FileUpload1" runat="server" /><br />
            <br />
            <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Upload Photo" />&nbsp;<br />
            <br />
            <asp:Label ID="Label1" runat="server"></asp:Label></div>
            </form>
            <p>
        </td>
    </tr>
</table>

</body>
</html>

<script runat="server">

Protected Sub Button1_Click(ByVal sender As Object,ByVal e As System.EventArgs)

    button1.Text="Uploading, Please Wait..."

    If FileUpload1.HasFile Then
        Try
            Dim Ext
            Ext = Lcase(Right(FileUpload1.PostedFile.F开发者_StackOverflow社区ileName, 3)) 
            If Ext = "jpg" or Ext = "peg" Then

            FileUpload1.SaveAs(Server.MapPath("..\" & Session("user_name") & "\photos\photo1_raw.jpg"))
            response.redirect("done.asp?action=done&photo=1#photos")
            Label1.Text = "File name: " & _
            FileUpload1.PostedFile.FileName & "<br>" & _
            "File Size: " & _
            FileUpload1.PostedFile.ContentLength & " kb<br>" & _
            "Content type: " & _
            FileUpload1.PostedFile.ContentType

            Else
            Label1.Text = "ERROR: Nothing Saved - Photo must be a .jpg or .jpeg format."
            end if

        Catch ex As Exception
            Label1.Text = "ERROR: " & ex.Message.ToString()
        End Try
    Else
        Label1.Text = "You have not specified a file."
    End If
End Sub

</script>

The button click event method is executing on the server, not in the browser.
To get the effect you are looking for you will need to write a client side function in javascript, ideally using a javascript framework such as jquery, so this button text change occurs in the browser before the event is fired back to the server for processing.