下面的代码使用API函数FindWindow查找名称为窗体a的窗体,并调用API函数SendMessage向目标窗体发送消息关闭目标窗体。
public const int WM_CLOSE = 0x10;
[DllImport("user32.dll", EntryPoint = "SendMessageA")]
public static extern int SendMessage(IntPtr hwnd, int wMsg, int wParam, int lParam);
[DllImport("User32.dll", EntryPoint = "FindWindow")]
private static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
IntPtr hwnd_win;
hwnd_win = FindWindow(null, "窗体a");
SendMessage(hwnd_win, WM_CLOSE, 0, 0);