How to Validate a TextBox to accept only String - Not any numeric(int ,decimal...)

[Behseini]

Hi guys,
I just wonder how i can validate a TextBox( like txtName) to accept just string value and not any numeric value?
Cloud u please let me know how I can do it? should I use a try and catch block?
Thanks

[BigEd781]

No, for the love of God, don't use a try/catch block to control the flow of your program

This is easily done one of two ways.

1. Use a MaskedTextBox if you need a specific format.
2. Handle the KeyDown event and check the input. If it is numeric, set e.Handled to true and nothing will appear in the TextBox.

[DataMiser]

In this case you would want to set e.handled to true if it is numeric since the goal is to not allow numeric characters. If you are going for names then you may also want to trap most other characters and allow only A-z as well as backspace.

[BigEd781]

yes, data is right. I must have read the first post backward.

[shail2k4]

You may use the following code to validate,

//Keypress event of your textbox
private void txtTarget_KeyPress(object sender, KeyPressEventArgs e)
        {
            int x = (int)e.KeyChar;
            e.Handled = !ValidateAlpha(x);
        }

//Validation function
public static bool ValidateAlpha(int keyAscii)
        {
            if (keyAscii >= 65 && keyAscii <= 90)
                return true;
            else if (keyAscii >= 97 && keyAscii <= 122)
                return true;
            else if (keyAscii == 8 || keyAscii == 13)
                return true;
            return false;
        }

[Alsvha]

There is a .net regular expression validator control to use in asp.net.

[CuteAssistant]

There is a .net regular expression validator control to use in asp.net.

Iam sure the code above would have helped you in ASP.net or C#. Why dont you reply or atleast mark it as resolved?

Regards,
CT.

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[CuteAssistant]

KeyDOwn event should work. You can check for an ascii range, else set e.cancel = true, so the key will not be processed. It works well.

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[partho]

A simple textbox to handle this.

public class TextOnlyBox:TextBox
{

protected override void OnKeyPress(KeyPressEventArgs e)
{
//Mark the event as handled, the base method won't process this.
e.Handled = (char.IsNumber(e.KeyChar));
base.OnKeyPress(e);
}

protected override void OnValidating(CancelEventArgs e)
{
//Validation is required, as someone can copy paste the data
//I even override the Text property to format the values
//Remove any number, if there
char[] CharsInTheText = this.Text.ToCharArray();
//use a stringbuilder, it is very efficient for appeding string
StringBuilder StringBuilder = new StringBuilder(CharsInTheText.Length, CharsInTheText.Length);

foreach (char CharInTheText in CharsInTheText)
{
if (! char.IsNumber(CharInTheText))
{
StringBuilder.Append(CharInTheText);
}

}
Text = StringBuilder.ToString();

base.OnValidating(e);
}

}