Deny Use of Splitter in PropertyGrid Control

Question

Is there any way to deny user from using Splitter in PropertyGrid Control. I go through all the properties of PropertyGrid Control, but I did not find to disable it. Is anything I am missing. Is there anyway to do it programatically. I am using C# Winforms VS2010.

Thanks

Answer 1

Looking at the source code for the PropertyGrid control: MSDN PropertyGrid

To prevent the horizontal divider behavior, override the OnMouseDown and OnMouseMove methods. To prevent the vertical divider behavior, one approach is to use a IMessageFilter and consume the mouse events when the location of the mouse is near the divider location.

public class MyForm3 : Form, IMessageFilter {

    PropertyGrid pg = new MyPropertyGrid { Dock = DockStyle.Fill };
    Control gridView = null;
    MethodInfo miSplittlerInside = null;

    public MyForm3() {
        Controls.Add(pg);
        pg.SelectedObject = new Button { Text = "Bob" };

        var f = typeof(PropertyGrid).GetField("gridView", BindingFlags.Instance | BindingFlags.NonPublic);
        gridView = (Control) f.GetValue(pg);
        miSplittlerInside = gridView.GetType().GetMethod("SplitterInside", BindingFlags.Instance | BindingFlags.NonPublic);

        Application.AddMessageFilter(this);
    }

    private const int WM_MOUSEMOVE = 0x200;
    private const int WM_LBUTTONDOWN = 0x201;
    private const int WM_LBUTTONDBLCLK = 0x203;

    public bool PreFilterMessage(ref Message m) {
        if (m.HWnd == gridView.Handle) {
            if (m.Msg == WM_MOUSEMOVE || m.Msg == WM_LBUTTONDOWN || m.Msg == WM_LBUTTONDBLCLK) {
                Point pt = new Point(m.LParam.ToInt32());
                bool inside = (bool) miSplittlerInside.Invoke(gridView, new Object[] { pt.X, pt.Y });
                if (inside) {
                    return true;
                }
            }
        }
        return false;
    }

    class MyPropertyGrid : PropertyGrid {
        protected override void OnMouseMove(MouseEventArgs me) {
            //base.OnMouseMove(me);
            // do nothing, prevent user from moving the split bar
        }

        protected override void OnMouseDown(MouseEventArgs me) {
            //base.OnMouseDown(me);
        }
    }
}

Note: Not calling the base methods will have the side effect that any listeners for those events will not be triggered.

Clarification: The code prevents the purple splitter. Is your question referring to the orange or purple?