C#中怎么调用API函数keyboard_event函数？介绍一下用法？

[DllImport("user32.dll", EntryPoint = "keybd_event", SetLastError = true)]
private static extern void keybd_event(byte bVk, byte bScan, uint dwFlags, uint dwExtraInfo);

...

private void button1_Click( object sender, EventArgs e )
{
const byte VK_F1 = 0x70;
const int KEYEVENTF_KEYUP = 0x02;
keybd_event(VK_F1, 0, 0, 0);
keybd_event(VK_F1, 0, KEYEVENTF_KEYUP, 0);
}