Question

i want to make a TextBox numeric. The Idea is to check the pressed Key before the Text is shown in the TextBox. I implement the Method KeyDown() of the TextBox.
Here is my Code:

private void txtX_KeyDown(object sender, KeyEventArgs e)
{
    if (!char.IsDigit(e.KeyChar) && !char.IsControl(e.KeyChar))
    {
        e.Handled = true;
    }
}

KeyEventArgs has no KeyChar (I got this from a tutorial)

I use WPF

Answer 1

For windows form

e.SuppressKeyPress = !(e.KeyValue >= 48 && e.KeyValue <= 57);
For wpf

e.Handled = !("D1D2D3D4D5D6D7D8D9D0".Contains(e.Key.ToString()));

Im using VS2010
Using the same logic U can do a better solution, more elegant 🙂