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Number of Uploaded files function does not show the error message

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User351619809 posted

am trying to limit the number of files that can be uploaded to 2. I have the following validator and code to resolve this issue:

  <asp:ValidationSummary runat="server" ID="ValidationSummary1" 
                   DisplayMode="BulletList" ShowMessageBox="false" ShowSummary="True" CssClass="alert alert-danger" />

     <asp:FileUpload runat="server" ID="UploadPDF" AllowMultiple="true" accept=".pdf"  /> 
    
     <asp:CustomValidator Display="None" ID="customValidatorUpload" runat="server" ErrorMessage="Only five files can be uploaded" ControlToValidate="UploadPDF" ClientValidationFunction="ValidateFile2();" />

Below is the ValidateFile2() function:

   <script>
        function ValidateFile2(sender, args) {
            
            var fileCount = document.getElementById('UploadPDF').files.length;
            if (fileCount > 2) 
            {
                args.IsValid = false;
               
            }
            else if (fileCount <= 0) 
            {
                args.IsValid = false;
            }

            args.IsValid = true; 
        }
    </script>

When I try to upload more than 2 files, I dont see any error message. I am not sure what am I doing wrong.

Any help will be greatly appreciated.

Monday, September 14, 2020 12:28 AM

Answers

User-939850651 posted

Hi anjaliagarwal5,

I created a simple example using the code you provided, and I modified part of the code to fix your problem.

Please refer to the following code:

<head runat="server">
    <title></title>
    <script> 
        function ValidateFile2(sender, args) {
            var fileCount = document.getElementById('UploadPDF').files.length;
            console.log(fileCount)
            if (fileCount > 2) {
                args.IsValid = false;
            }
            else if (fileCount <= 0) {
                args.IsValid = false;
            } else {
                args.IsValid = true;
            }
        }
    </script>
</head>
<body>
    <form id="Form1" runat="server">
        <asp:ValidationSummary runat="server" ID="ValidationSummary1"
            DisplayMode="BulletList" ShowMessageBox="false" ShowSummary="True" CssClass="alert alert-danger" />

        <asp:FileUpload runat="server" ID="UploadPDF" AllowMultiple="true" accept=".pdf" />

        <asp:CustomValidator ID="customValidatorUpload"
            Display="Static" runat="server"
            ErrorMessage="Only five files can be uploaded"
            ControlToValidate="UploadPDF"
            ClientValidationFunction="ValidateFile2" />
    </form>
</body>

Result:

The value of the ClientValidationFunction attribute is just the function name.
In your code, args.IsValid is always true in the function.

Please check them.

Best regards,

Xudong Peng

Marked as answer by Anonymous Thursday, October 7, 2021 12:00 AM

Monday, September 14, 2020 5:40 AM

Answered by:

Number of Uploaded files function does not show the error message

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