Validation:How to remove special characters from textbox?

The KeyPress Event could miss scenarios such as when a user pastes something into a textbox using only the mouse. In my opinion, John's suggesion of using the TextChanged is a better event to use. Also, you may want to research Regular Expressions.

Here[^] is a C# article that could help give you an idea of how to use them.

Or here are some Google[^] links that could help.

Try this may this help you
Inside Class Declare this Function:

Public Sub txtValidation(ByVal e)
        If (Asc(e.KeyChar)) < 65 Or (Asc(e.KeyChar)) > 90 And (Asc(e.KeyChar)) < 97 Or (Asc(e.KeyChar)) > 122 Then

            If (Asc(e.KeyChar) <> 32) Then
                e.Handled = True
            End If
        End If
        If (Asc(e.KeyChar) = 8) Then
            e.Handled = False
        End If
    End Sub

The above will avoid you to enter Special Character but allow you to Input Alphabets Only.And the Below given function will avoid you to enter Special Characters but allow you to Enter Numbers only

Public Sub txtNumberValidation(ByVal e)
        If (Asc(e.KeyChar) < 48) Or (Microsoft.VisualBasic.Asc(e.KeyChar) > 57) Then
            e.Handled = True

        End If
        If (Asc(e.KeyChar) = 8) Then
            e.Handled = False
        End If
    End Sub

Call this Function from your Class to your Form In the Keypress event of your TextBoxes if having Problem follow
this Link [^]

I have used ASCII codes to detect the Entered Value.Research on it You Will definitely get your Required Solution.Try it

Or Finally Try This Function

Public Sub txtAlphaNumericValidation(ByVal e)
        If (Asc(e.KeyChar) < 48) Or (Microsoft.VisualBasic.Asc(e.KeyChar) > 57) And (Asc(e.KeyChar)) < 65 Or (Asc(e.KeyChar)) > 90 And (Asc(e.KeyChar)) < 97 Or (Asc(e.KeyChar)) > 122 Then
            e.Handled = True

        End If
        If (Asc(e.KeyChar) = 8) Then
            e.Handled = False
        End If
    End Sub

Good Luck !!

Hi

use this expression ^[A-Za-z0-9]$
in asp:RegularExpressionValidator

Use replace method

textbox1.text = textbox1.text.replace("*","").replace("&","")

like this you can remove all special character