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home / developersection / forums / is there a way to check fileupload has file or not in client side.if it has i want to enable button
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Is there a way to check Fileupload has file or not in client side.If It has i want to enable button

Nattapong Unaregul 8326 21 Jul 2012
Here is my code in default.aspx .The default.aspx is in the content place
<%@ Page Language="VB" MasterPageFile="~/MasterPage.master" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="_Default" title="Untitled Page" %>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
   <tr> <td><asp:FileUpload ID="FileUpload1" runat="server" " /></td>
           <td> <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ErrorMessage="Task cannot be blank"
        InitialValue="" ControlToValidate="FileUpload1"> </asp:RequiredFieldValidator></td></tr>
   <tr><td><asp:Button ID="SaveBT" runat="server" Text="Button" Enable = "False"  /></td></tr> 
  </table>    
  

</asp:Content>


vb.net vb.net
Updated 15 May 2026
Nattapong Unaregul
Nattapong Unaregul

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2 Answers

Nattapong Unaregul
Nattapong Unaregul 22 Jul 2012
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Thank for your advice.Here is my solution

<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">
    <asp:FileUpload ID="FileUpload1" runat="server" onchange="FileUpload_OnChange(this,event);"   />  &nbsp; &nbsp; &nbsp;
<table>
   <tr>  <td> <input type="button" value = "Preview" /></td> </tr> 
    </table>
    
    <script  language="javascript" type ="text/javascript" >
        function Alert(myButton) {
            alert(myButton)
}
            function changeColor(myButton) {
            myButton.value = "OK";
        }
        function FileUpload_OnChange(sender, e) {

            document.getElementById('<%=Button1.ClientID %>').disabled = false;
        }
    </script>
</asp:Content>
Anonymous User
Anonymous User 21 Jul 2012
Report Abuse
Hi Nattapong Unaregul,
Check out the following link it might be resolve your problem.....
https://www.mindstick.com/Articles/331/validating-fileupload-control-for-specific-file-type-and-required-field
https://www.mindstick.com/Articles/176/fileupload-control-in-asp-dot-net
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