I have a one problem for backspaces in c#(windows)

I have written following code in keyup event for textbox i.e (Text Box is placed On 5 th panel)

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if(e.keydata==keys.back)

{
sendkeys.send=("+{BS}");
Sendkeys.send={Break};
}
It will delete ONLY ONE char. When I'm pressing backspace button but when I'm holding backspace button it will not delete the complete chars. Just it will deldete one char for one pressing. Could you please give me the solution. and I was tried keydown and key press event also.Thanks in advance

private void textBox1_KeyPress(object sender, KeyPressEventArgs e) {
    // Do whatever here
    e.Handled = true;
}