winform右键菜单

 public partial class Form1 : Form
     {
         ContextMenuStrip cms;
         Bitmap bm ;
         public Form1()
         {
             InitializeComponent();
         }
         private void Form1_MouseDown(object sender, MouseEventArgs e)
         {  

             if (e.Button == MouseButtons.Right)
             {
                 if (cms.Items.Count > )
                 {
                     cms.Items.Clear();
                 }
                 //带图表项
                 cms.Items.Add("tubiao",bm,new EventHandler(tubiao_Handler));
                 cms.Items.Add("mouseright1");
                 cms.Items.Add("-");
                 cms.Items.Add("mouseright2");
                 cms.Items.Add("-");
                 cms.Items.Add("mouseright3");
             }
             else
             {
                 return;
             }
             //处理显示位置
             int w= Width-e.X;
             if (w < cms.Width)
             {
                 cms.Show(this, e.X - cms.Width, e.Y);
             }
             else
             {
                 cms.Show(this,e.X,e.Y);
             }  

         }
         public void tubiao_Handler(object sender, EventArgs e)
         {
             MessageBox.Show("this is tubiao", "tubiao", MessageBoxButtons.YesNo);
         }
         private void Form1_Load(object sender, EventArgs e)
         {
             cms = new ContextMenuStrip();
             bm = new Bitmap("Resources/Icon1.ico");//图标存放位置
         }
     }