winforms - C# Application-Wide Left Mouse Click Event

Question

I want to play a sound when the left mouse button is clicked anywhere in my form without having to place Mouse click events on every single control in the form. Is there a way to accomplish this?

Answer 1

You can detect the Windows notification before it is dispatched to the control with the focus with the IMessageFilter interface. Make it look similar to this:

public partial class Form1 : Form, IMessageFilter {
    public Form1() {
        InitializeComponent();
        Application.AddMessageFilter(this);
        this.FormClosed += delegate { Application.RemoveMessageFilter(this); };
    }

    public bool PreFilterMessage(ref Message m) {
        // Trap WM_LBUTTONDOWN
        if (m.Msg == 0x201) {
            System.Diagnostics.Debug.WriteLine("BEEP!");
        }
        return false;
    }
}

This works for any form in your project, not just the main one.