can't determine '.' keychar for a textbox KeyPress event

Question

I use below code to not allowing any character except numbers in a textbox ... but it allows '.' character! I don't want it to allow dot.

    private void txtJustNumber_KeyPress(object sender, KeyPressEventArgs e)
    {
        if (!char.IsDigit((char)(e.KeyChar)) &&
            e.KeyChar != ((char)(Keys.Enter)) &&
            e.KeyChar != (char)(Keys.Delete) &&
            e.KeyChar != (char)(Keys.Back)&&
            e.KeyChar !=(char)(Keys.OemPeriod))
        {
            e.Handled = true;
        }
    }

Answer 1

use this:

    if (!char.IsDigit((char)(e.KeyChar)) &&
            e.KeyChar != ((char)(Keys.Enter)) &&
            (e.KeyChar != (char)(Keys.Delete) || e.KeyChar == Char.Parse(".")) &&
            e.KeyChar != (char)(Keys.Back) 
            )

it is because Keys.Delete's char value is 46 which is the same as '.'. I do not know why it likes this.

Answer 2

You could try this instead (where textBox1 would be your textbox):

// Hook up the text changed event.
textBox1.TextChanged += textBox1_TextChanged;

...

private void textBox1_TextChanged(object sender, EventArgs e)
{
    // Replace all non-digit char's with empty string.
    textBox1.Text = Regex.Replace(textBox1.Text, @"[^\d]", "");
}

Or

// Save the regular expression object globally (so it won't be created every time the text is changed).
Regex reg = new Regex(@"[^\d]");

private void textBox1_TextChanged(object sender, EventArgs e)
{
    if (reg.IsMatch(textBox1.Text))
        textBox1.Text = reg.Replace(textBox1.Text, ""); // Replace only if it matches.
}

Answer 3

//This is the shortest way
private void txtJustNumber_KeyPress(object sender, KeyPressEventArgs e)
{
    if(!char.IsControl(e.KeyChar) && !char.IsDigit(e.KeyChar))
    {
        e.Handled = true; 
    }
}

Answer 4

try this code for your problem in keypress event :

   private void txtMazaneh_KeyPress(object sender, KeyPressEventArgs e)
    {
        if (!char.IsDigit(e.KeyChar) && (int)e.KeyChar != 8 ||(e.KeyChar= .))
            e.Handled = true;
    }