/// <summary>
/// Sends the specified message to a window or windows. The SendMessage function calls the
/// window procedure for the specified window and does not return until the window procedure
/// has processed the message.
/// </summary>
/// <param name="hwnd">The window handle of the sending window</param>
/// <param name="windowMessage">The message to be sent.</param>
/// <param name="wParam">Additional message-specific information.</param>
/// <param name="lParam">Additional message-specific information.</param>
public static void SendMessage(IntPtr hwnd, WindowsMessages windowMessage, IntPtr wParam, IntPtr lParam)
{
if (UnsafeNative.SendMessage(hwnd, (int)windowMessage, wParam, lParam) != 0)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
}
/// <summary>
/// Sends the specified message string to a window. The SendMessage function calls the window
/// procedure for the specified window and does not return until the window procedure has
/// processed the message.
/// </summary>
/// <param name="hwnd">A handle to the window whose window procedure will receive the message.</param>
/// <param name="message">The message to be sent to the window</param>
/// <exception cref="Win32Exception">Win32 error occures</exception>
/// <exception cref="ArgumentException">HWND is <see cref="IntPtr.Zero"/></exception>
/// <exception cref="ArgumentNullException"><paramref name="message"/> is null</exception>
/// <exception cref="ArgumentException"><paramref name="message"/> is empty</exception>
public static void SendMessage(IntPtr hwnd, string message)
{
if (hwnd == IntPtr.Zero)
{
throw new ArgumentException("HWND cannot be IntPtr.Zero");
}
if (message == null)
{
throw new ArgumentNullException("The message cannot be null");
}
if (message == "")
{
throw new ArgumentException("The message cannot be empty");
}
var messageBytes = Encoding.Default.GetBytes(message); /* ANSII encoding */
var data = new UnsafeNative.COPYDATASTRUCT
{
dwData = (IntPtr)100,
lpData = message,
cbData = messageBytes.Length + 1 /* +1 because of 0 termination */
};
if (UnsafeNative.SendMessage(hwnd, UnsafeNative.WM_COPYDATA, IntPtr.Zero, ref data) != 0)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
}
/// <summary>
/// The message is sent to all top-level windows in the system, including disabled or
/// invisible unowned windows, overlapped windows, and pop-up windows; but the message is not
/// sent to child windows.
/// </summary>
/// <param name="registeredWindowMessage">
/// The registered window message. use <see cref="Win32Api.RegisterWindowMessage(string)"/>
/// to register a message.
/// </param>
/// <param name="wParam">Additional message-specific information.</param>
/// <param name="lParam">Additional message-specific information.</param>
/// <exception cref="ArgumentException">Invalid registered window message</exception>
/// <exception cref="Win32Exception">Win32 error occures</exception>
public static void BroadcastMessage(uint registeredWindowMessage, IntPtr wParam, IntPtr lParam)
{
if (registeredWindowMessage < 0xC000)
{
throw new ArgumentException("Not a valid registered window message");
}
if (UnsafeNative.SendMessage(UnsafeNative.HWND_BROADCAST, (int)registeredWindowMessage, wParam, lParam) != 0)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
}