Right click menu under winforms

Put a ContextMenuStrip on your form, design your menu, then set the ContextMenuStrip property on the form to the component created.

Add a System.Windows.Forms.ContextMenuStrip item to the form, then set the form's ContextMenuStrip property.

After putting a ContextMenuStrip on your form, Add it to your Control (you can do it in Control's Properties) and then , use code like this for showing menu:

private void myTree_MouseClick(object sender, MouseEventArgs e)
{
     myTree.ContextMenu.Show(myTree, new Point(e.X, e.Y));
}

more on MSDN.