发送按键的有关问题

发送按键的问题
如何向一个不是当前窗口的窗体发送按键啊，比如发送个alt+a过去，如何实现啊，研究了好久都以失败告终，有没有高手能帮帮小弟的。

[解决办法]

C# code

// 声明部分[StructLayout(LayoutKind.Sequential)]internal struct MOUSEINPUT{    public int dx;    public int dy;    public int mouseData;    public int dwFlags;    public int time;    public IntPtr dwExtraInfo;}[StructLayout(LayoutKind.Sequential)]internal struct KEYBDINPUT{    public short wVk;    public short wScan;    public int dwFlags;    public int time;    public IntPtr dwExtraInfo;}[StructLayout(LayoutKind.Sequential)]internal struct HARDWAREINPUT{    public int uMsg;    public short wParamL;    public short wParamH;}[StructLayout(LayoutKind.Explicit)]internal struct Input{    [FieldOffset(0)]    public int type;                  // Mouse: 0; Keyboard: 1; hardware: 2    [FieldOffset(4)]    public MOUSEINPUT mi;    [FieldOffset(4)]    public KEYBDINPUT ki;    [FieldOffset(4)]    public HARDWAREINPUT hi;}[DllImport("user32.dll")]private static extern uint SendInput(uint nInputs, Input[] pInputs, int cbSize);//使用部分Input[] input = new Input[T_CartonID.Text.Length * 2 + 4];int i = 0;foreach (char nChar in MyText){    input[i].type = 1;    input[i].ki.wVk = Convert.ToInt16(nChar);    i++;    input[i].type = 1;    input[i].ki.wVk = Convert.ToInt16(nChar);    input[i].ki.dwFlags = 2;    i++;}// Enter keyinput[input.Length - 4].type = 1;input[input.Length - 4].ki.wVk = 0x0D;input[input.Length - 3].type = 1;input[input.Length - 3].ki.wVk = 0x0D;input[input.Length - 3].ki.dwFlags = 2;input[input.Length - 2].type = 1;input[input.Length - 2].ki.wVk = 0x0A;input[input.Length - 1].type = 1;input[input.Length - 1].ki.wVk = 0x0A;input[input.Length - 1].ki.dwFlags = 2;SendInput((uint)input.Length, input, Marshal.SizeOf(input[0]));
[解决办法]
如果向非当前窗体发送，则需要先找到目标窗体的句柄，然后发送对应的消息即可
[解决办法]
可以用API的FindWindow 和 SetForegroundWindow来强制聚焦到其他应用程序上


private void Form1_Load(object sender, EventArgs e)
{
     KeyboardHook keyboardHook = new KeyboardHook();//全局按键
      keyboardHook.KeyDown += new KeyEventHandler(keyboardHook_KeyDown);
     keyboardHook.Start();
}

void keyboardHook_KeyDown(object sender, KeyEventArgs e)
{
      if (e.KeyCode == Keys.F2)
     {
          SendKeys.Send("%A");//发送ALT+A
      }
}
[解决办法]
不好意思，SendKeys.Send("%A");//发送ALT+A
A应该是小写，大写不行，写错了。