I want to write temperature in my textbox for example:"38.8". But I dont want to use maskedTextbox.

My code:

  private void textBox_TextChanged() 
  {
     if(textbox. text. length() == 3)
     {
       textbox. Text  = "." ;
     } 
  }

But it doesnt work. I would like that the backspace key avoid comma. How to do that?

CodePudding user response：

Not the best way but will do the job. You can use KeyPress event for your textbox

        private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (!char.IsControl(e.KeyChar) && !char.IsDigit(e.KeyChar))
            {
                e.Handled = true;
            }
            if ((e.KeyChar != (char)System.Windows.Forms.Keys.Back))
            {

                if ((sender as TextBox).Text.Length == 2)//set dot(.) after 2 numbers.
                {
                    (sender as TextBox).Text  = ".";
                    (sender as TextBox).SelectionStart = this.Text.Length;
                }
            }
        }