网上扒来的代码，保存下，以便下次查找
HWND hWnd;
hWnd = GetForegroundWindow(); // 得到当前窗口
DWORD FormThreadID = GetCurrentThreadId(); // 本程序的线程ID
// 当前窗口的线程ID
DWORD CWndThreadID = GetWindowThreadProcessId(hWnd, NULL);
// 附加输入线程
AttachThreadInput(CWndThreadID, FormThreadID, true);
hWnd = GetFocus();
AttachThreadInput(CWndThreadID, FormThreadID, false);
String SS="可以";
for (int i = 1; i <= SS.Length(); i++)
{
PostMessage(hWnd, WM_CHAR, (WPARAM)(SS[i]&0xFF),0);
}