VB.NET email validation with Regex

Question

I've tried implementing a rather simple email validation function that seems return a false match even though the input is a valid email. I have searched for any issues with the existing regex but it seems to be correct.

Even though the match returns a false value the program is stepping to the next validation level (which it shouldn't).

Here is the email validation function.

Function EmailAddressChecker(ByVal emailAddress As String) As Boolean
        Dim regExPattern As String = "^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}$"
        Dim emailAddressMatch As Match = Regex.Match(emailAddress, regExPattern)
        If emailAddressMatch.Success Then
            Return True
        Else
            Return False
        End If
End Function

And for the form validation that calls upon the email validation function.

If (String.IsNullOrEmpty(EmailTextBox.Text) OrElse EmailAddressChecker(EmailTextBox.ToString)) Then
            MessageBox.Show("Please enter a valid email addresss")
            Return False
End If

The call for all of this happens on an click event which triggers a cascading serious of If statements checking to see if all the fields are set.

Skipping a large chunk of code the click event asks if "AreFieldsSet <> True". Inside of the "AreFieldsSet" function contains all the validation for multiple inputs; one of which is the email validation if statement.

Solution

Are the emails in UpperCase? If they aren't, they won't match.

If you want to modify the Regex so that it is Case insensitive, use this:

"^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$"

Comments

[covertCoder]

I haven't tested this, but isn't this functionally equivalent to what the original code does? Less code, but both should do the same thing.

[Admin]

I did notice however that the email address is equal to ""System.Windows.Forms.TextBox, Text: abc@aosdf". This obviously needs to be dealt with. I think I had a problem with this before.. Fix is something like "public override string ToString()" ????

[covertCoder]

Accessing the textbox via txtMyTextbox.Text should return the email string in its purest form. Calling txtMyTextBox.ToString() should return the string you provided "System.Windows.Forms.TextBox, Text: abc@aosdf".