Validating WinForms TextBox (in C#)

Question

In TextBox_Leave event i need to check whether numbers entered in textbox is in serial number or not.If it is not in order then i need to display a message as \"number\" is

Answer 1

I will show you how to validate Validating WinForms TextBox (in C#).

1. Create a function:

   public static void ChkBlankTextBoxes(object sender, string type)
   {
   
       if (sender is TextBox)
       {
           TextBox textbox = sender as TextBox;
           if (string.IsNullOrEmpty(textbox.Text))
           {
               MessageBox.Show("Please enter correct value value..");
               textbox.Focus();
   
           }
       }
   }
   

2. Call to created function:

   ChkBlankTextBoxes(txt_userID, textBoxtype);
   
   ChkBlankTextBoxes(txt_password, textBoxtype);