I try to validate FileUpload
control to check the extension of files by this regular expression
<asp:RegularExpressionValidator ID="RegularExpressionValidator5" ValidationGroup="PersonalGroup"
ControlToValidate="FileUpload1" Runat="Server"
ErrorMessage="Only .pdf & .doc files are allowed" ValidationExpression="[^\.]\.pdf\.docx\.doc$" />*</asp:RegularExpressionValidator>
my problem to check the FileUpload already has file or not before i click the button submit because i got NullReferenceException
if don't have file i try to make this
if (FileUpload1.HasFile)
{
book.Book_File = System.IO.Path.GetPathRoot(FileUpload1.PostedFile.FileName);
}
but the problem still exist if the user didn't uploaded any file. How to check the FileUpload
is required filed before submit?
Use RequiredFieldValidator
. Its available in the controls list.
Something like :
<asp:RequiredFieldValidator ID="rfvFileupload" runat="server" Display="Dynamic" ErrorMessage="Image is Required !" ControlToValidate="yourFileUploadID"></asp:RequiredFieldValidator>
You could also use below condition check behind your button:
If (page.isValid) {
//here goes your code behind button
}
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