C# MonthCalendar control Get date under cursor

Question

Is there a way to get the date under the cursor on the MonthCalendar control? I'd like to collect this on right click to pass into a dialog. Right clicking doesn't seem to trigger it's click event. I tried overloading the MouseDown event, but that didn't seem to help either.

Answer 1

Yes, MonthCalendar has its own context menu so the right-button click event is disabled. Surgery is required to re-enable it. Add a new class to your project and paste the code shown below. Compile. Drop the new control from the top of the toolbox onto your form.

using System;
using System.Drawing;
using System.Windows.Forms;

class MyCalendar : MonthCalendar {
    public event MouseEventHandler RightClick;

    protected override void WndProc(ref Message m) {
        if (m.Msg == 0x205) {   // Trap WM_RBUTTONUP
            var handler = RightClick;
            if (handler != null) {
                var pos = new Point(m.LParam.ToInt32());
                var me = new MouseEventArgs((MouseButtons)m.WParam.ToInt32(), 1, pos.x, pos.y, 0);
                handler(this, me);
            }
            this.Capture = false;
            return;
        }
        base.WndProc(ref m);
    }
}

You now have a RightClick event that you can subscribe. Something similar to this:

    private void myCalendar1_RightClick(object sender, MouseEventArgs e) {
        var hit = myCalendar1.HitTest(e.Location);
        if (hit.HitArea == MonthCalendar.HitArea.Date) {
            var dt = hit.Time;
            MessageBox.Show(dt.ToString());   // Display your context menu here
        }
    }