Close ToolStripMenuItem when mouse leaves ToolStripMenuItems

Question

I am new to windows Forms so I am wondering what the best approach to my problem is.

I want the ToolStripMenuItems of the ToolStripDropDownMenu to close only when the user's mouse leaves the area containing them (All the ToolStripMenuItems)

Currently I have the following code:

             {  ToolStripDropDownMenu menu = new ToolStripDropDownMenu();
                menu.AutoClose = true;

                foreach (ToolStripMenuItem toolStripItem in this.collectionToolStripMenuItems)
                {
                    menu.Items.Add(toolStripItem);
                }

                menu.Show(sender, e.ControlLocation);
            }

I define the toolStripMenuItems in the list: collectionToolStripMenuItems with the code:

            ToolStripMenuItem ToolStripItem = new ToolStripMenuItem(item.Name);
            ToolStripItem.Click += new EventHandler(this.ValueMenuItem_Click);
            ToolStripItem.MouseLeave += new EventHandler(MouseLeave);
            ToolStripItem.MouseEnter += new EventHandler(MouseEnter);

where

    private void MouseLeave(object sender, EventArgs e)
    {
        ToolStripMenuItem item2 = (ToolStripMenuItem)sender;
        ToolStripDropDownMenu menu = (ToolStripDropDownMenu)item2.Owner;
        menu.Hide();
    }

    private void MouseEnter(object sender,EventArgs e)
    {
        ToolStripMenuItem item2 = (ToolStripMenuItem)sender;
        ToolStripDropDownMenu menu = (ToolStripDropDownMenu)item2.Owner;
        menu.Show();
    }

    private void ValueMenuItem_Click(object sender, EventArgs e)
    {// Do something
        ToolStripMenuItem item2 = (ToolStripMenuItem)sender;

            ToolStripDropDownMenu menu = (ToolStripDropDownMenu)item2.Owner;
            menu.Show();

            return;
    }

This works however each time the user clicks or leaves a toolStripMenuItem the dropDown closes for a very brief moment so it looks like the whole thing is flashing.

Can someone please recommend a better approach? Many thanks!

Answer 1

I am facing a similar problem. Let me share the whole solution. Let toolStripMenuItem be our ToolStripMenuItem object.

Do this OUTSIDE the Form1.Designer.cs:

1. Set AutoClose to falsetoolStripMenuItem.DropDown.AutoClose = false;
2. Add a new Event Handler that will close the drop down when mouse leaves the drop down menu toolStripMenuIntem.DropDown.MouseLeave += System.EventHandler(this.DropDown_MouseLeave)

You need of course to create this event handler:

    private void DropDown_MouseLeave(object sender, EventArgs e)
    {
        // Close DropDown when mouse leave drop down control:          
        toolStripMenuItem.DropDown.Close();
    }

The solution above is partial. You may need also to close the dropdown when mouse leaves the toolStripMenuItem control itself. For that, what I did is to check if mouse is inside drop down when it leaves toolStripMenuItem control. If mouse is outside toolStripMenuItem and outside dropdown, then I close the drop down menu.

private void ToolStripMenuItem_MouseLeave(object sender, EventArgs e)
{
        Point cursor = toolStripMenuItem.DropDown.PointToClient(Control.MousePosition);
        bool cursorInDropDown = toolStripMenuItem.DropDown.ClientRectangle.Contains(cursor);

        if (!cursorInDropDown)
        {
            // Cursor is NOT in drop down. Close Drop down!
            toolStripMenuItem.DropDown.Close();
        }
    }

Remember to link the event MouseLeave of the toolStripMenuItem object to ToolStripMenuItem_MouseLeave.

Hope it helps!