Question

I have input constraints on textbox that it will only accept the int and until it can be parsed by Int64. The question is it clears out because he is assigning to String.Empty but what if its is not parsable by Int64 then i want to suppress that keypress. I tried adding code to keydown event that i have but it will also suppress the Int keys.

public static void SetInt64Input(Control tb)
    {
       tb.KeyDown += (sender, e) => {
        if (!IsIntKeyOrAlwaysAcceptableKey(e))
       //if not int key suppress it; Ex: A,B,.etc
            e.SuppressKeyPress = true;
       };
       tb.TextChanged += (s, e) => ClearAllNonInt64Inputs(tb);

    }

    private static void ClearAllNonInt64Inputs(Control tb)
    {
        long i;
        if (!Int64.TryParse(tb.Text, out i))
            tb.Text = String.Empty;
        else
            tb.Text =  Int64.Parse(tb.Text).ToString();
    }

i tried doing

 if(!Int64.TryParse(((TextBox)sender).Text,out junk)
    e.SuppressKeyPress = true;

but it dint work.

Answer 1

i am not sure whats the question.sorry.
But if the input is not parsable due to its out of length of Int64 (more than 4 bytes), then i think restricting the numbers of characters in the Textbox may help. And if its not parsable due to a non-integer value, then use of IsNotDigit function will be helpfull in keypress event.