validating textbox in windows form applications

Question

My scenario is:

Not allowing spaces at starting position of textbox after enter one or more characters text box allows spaces

Below not applicable to my sce

Answer 1

you should use the regex

        string strRegex = @"^([\w]+.*)$";
        string strTargetString =  textBox1.Text;

        if (!Regex.IsMatch(strTargetString, strRegex))
        {
            // show error that spase not allow at the bigin of string
        }