c# winform e.Handled = true; 键盘不受限，怎么回事？高手解答一下

Question

namespace WindowsFormsApplication32
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

    private void Form1_KeyDown(object sender, KeyEventArgs e)
    {
          e.Handled = true;

    }
}

}

Answer 1

Form1_KeyDown事件注册了么？