C# SendMessage Method Explained

The SendMessage method is a function in the Windows API that can be called in C# using P/Invoke. Its definition is as follows:

[DllImport("user32.dll", CharSet = CharSet.Auto)]
public static extern IntPtr SendMessage(IntPtr hWnd, int msg, IntPtr wParam, IntPtr lParam);

1. The hWnd parameter is the handle of the target window, used to specify which window the message should be sent to.
2. “The msg parameter is a message code used to specify the type of message to be sent.”
3. wParam and lParam are parameters of the message, and their specific meanings depend on the type of message.

Using the SendMessage method, we can achieve and control interactions between various windows, such as sending mouse clicks, keyboard inputs, and custom messages to a specified window. This can be very useful for certain specific requirements or functionalities, but caution must be taken to avoid compromising system stability.