Checking File Upload Size using Custom Validator in ASP.NET and Javascript

ASP.NET, Javascript Comments Off on Checking File Upload Size using Custom Validator in ASP.NET and Javascript

The following snippet uses custom validator control  and javascript to check the file upload size and disabling the form submission if the file size exceeds the limit. The form will not submit if the validator fails.

ASPX.PAGE

<asp:FileUpload ID=”fileUpload” runat=”server” />
<br />
<asp:CustomValidator ID=”customValidatorUpload” runat=”server” ErrorMessage=”Files is too large” ControlToValidate=”fileUpload” ClientValidationFunction=”ValidateFileSize” />
<br />
<asp:Button ID=”button_fileUpload” runat=”server” Text=”Upload File” OnClick=”button_fileUpload_Click” />

Javascript custom validate function

<script type=”text/javascript”>
function ValidateFileSize(sender, args) {
var maxFileSize = 1 // 1MB -> 1 * 1024 – to check in KB – Kilo Bytes
var fileUpload = document.getElementById(“<%=fileUpload.ClientID%>”);
if (typeof (fileUpload.files) != “undefined”) {
var size = parseFloat(fileUpload.files[0].size / 1024).toFixed(2);

if (size < maxFileSize) {

args.IsValid = true;
} else {

args.IsValid = false;
}

} else {
alert(“You have an outdated browser”);

}

}

</script>

This snippet will not work in old browsers.



Author

Search

Back to Top