示例代码：

protected override bool ProcessCmdKey(ref Message msg,Keys keyData)
{
    // look for the expected key
    if (keyData == Keys.A)
    {
        // take some action
        MessageBox.Show("The A key was pressed");
 
        // eat the message to prevent it from being passed on
        return true;
 
        // (alternatively,return FALSE to allow the key event to be passed on)
    }
 
    // call the base class to handle other key events
    return base.ProcessCmdKey(ref msg,keyData);
}

至于为什么this.Focus()不起作用,这是因为表单本身不能具有焦点.特定控件必须具有焦点,因此当您将焦点设置到窗体时,它实际上将焦点设置为可以接受具有最低TabIndex值的焦点的第一个控件.在这种情况下,那是你的按钮.