Question

Goal:
Right clicking in the listview and choose different option.

Problem:
There are two problem:
*When I’m right clicking, the left corner of the menu is not exactly located in the arrow’s spot location.
*How do I create a line in the menu?

The main problem about the menu

Need support to create these two redmark.

private void lstV_Stock_MouseUp(object sender, MouseEventArgs e)
{
    switch (e.Button)
    {

        // Right mouse click
            case MouseButtons.Right:


                ContextMenu myContextMenu = new ContextMenu();

                MenuItem menuItem1 = new MenuItem("New product");
                MenuItem menuItem2 = new MenuItem("Delete");
                MenuItem menuItem3 = new MenuItem("Add quantity");


                // Clear all previously added MenuItems.
                myContextMenu.MenuItems.Clear();

                myContextMenu.MenuItems.Add(menuItem1);
                myContextMenu.MenuItems.Add(menuItem2);
                myContextMenu.MenuItems.Add(menuItem3);

                if (lstV_Stock.SelectedItems.Count > 0) 
                {

                    foreach (ListViewItem item in lstV_Stock.SelectedItems)
                    {
                        myContextMenu.MenuItems[1].Visible = true;
                        myContextMenu.MenuItems[2].Visible = true;
                        myContextMenu.MenuItems[0].Visible = false;
                    }

                }
                else
                {
                    myContextMenu.MenuItems[1].Visible = false;
                    myContextMenu.MenuItems[2].Visible = false;
                    myContextMenu.MenuItems[0].Visible = true;
                }

                myContextMenu.Show(lstV_Stock, this.PointToClient(Cursor.Position), LeftRightAlignment.Right);



                menuItem1.Click += new System.EventHandler(this.menuItem1_Click);


                break;

        }

Answer 1

For the positioning, you can replace your

myContextMenu.Show(lstV_Stock, this.PointToClient(Cursor.Position), LeftRightAlignment.Right);

to

myContextMenu.Show(lstV_Stock, e.Location(), LeftRightAlignment.Right);

or the point e.X,e.Y. Not from this.PointToClient, but from the MouseEventArgs generating the event. You can check wahat MouseEvent have here.