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

Try

 private void textBox1_KeyPress(object sender, KeyPressEventArgs e)         
 {             
     if (e.Handled = (e.KeyChar == (char)Keys.Space))             
     {                 
        if(((TextBox)sender).Text.Replace(" ","") == "")
        {
             MessageBox.Show("Spaces are not allowed");  
             ((TextBox)sender).Text = string.Empty;
        }           
     }          
 }