FT豹豹哥，你给“鼠标左键，弹出contextMenu”的程序

由于没有IDE环境，所以程序就尽量简单了
不说了，你看程序吧
using System;
using System.Windows.Forms;
using System.Drawing;
class useonpaint:Form
{
    public useonpaint()
    {;}
    
    static void Main()
    {
        Application.Run(new useonpaint());
    }
    
    protected override void OnMouseUp(MouseEventArgs e)
    {
       if (e.Button == MouseButtons.Left)    test(e);
       
        }
    private void test(MouseEventArgs e)
    {
        ContextMenu m = new ContextMenu();
        this.ContextMenu= m;
        // Create MenuItem objects.
        MenuItem menuItem1 = new MenuItem();
        MenuItem menuItem2 = new MenuItem();
    
        // Set the Text property.
        menuItem1.Text = "New";
        menuItem2.Text = "Open";