模拟键盘按键，将字符转换为虚拟键码

通过oemKeyScan和MapVirtualKey函数

oemKeyScan可以获得扫描码以及转换状态，状态有shift被按下，ctrl被按下，alt被按下等等。

MapVirtualKey将一虚拟键码翻译（映射）成一扫描码或一字符值，或者将一扫描码翻译成一虚拟键码。

 1 DWORD   sc, shift;
 2 unsigned   char   vkey;
 3 char   a;
 4 CString str = "abc";
 5 for (int i = 0; i<str.GetLength(); i++)//模拟键盘输出str中的字符
 6 {
 7     a = str.GetAt(i);
 8     sc = OemKeyScan(a);
 9     shift = sc >> 16;
10     vkey = MapVirtualKey(sc & 0xffff, 1);
11     if (shift)
12         keybd_event(VK_SHIFT, 0, 0, 0);
13     keybd_event(vkey, 0, 0, 0);
14     keybd_event(vkey, 0, KEYEVENTF_KEYUP, 0);
15     if (shift)
16         keybd_event(VK_SHIFT, 0, KEYEVENTF_KEYUP, 0);
17 }