C#

private void treeView1_MouseUp(object sender, MouseEventArgs e){
   if(e.Button == MouseButtons.Right)
   {      
       TreeNode clickedNode = tv.GetNodeAt(MousePosition);
       if(tv == node_1.1) treeView1.ContextMenu = contextMenu1;
       else if (tv == node_1.2) ... and so on
   }
}

private void treeView1_MouseUp(object sender, MouseEventArgs e){
   if(e.Button == MouseButtons.Right)   {
      TreeNode clickedNode = tv.GetNodeAt(MousePosition);
      if(clickedNode == node_1.1) treeView1.ContextMenu = contextMenu1;
      else if (clickedNode == node_1.2) ... and so on   }
   }

private void treeView1_MouseUp(object sender, MouseEventArgs e){
   if(e.Button == MouseButtons.Right)   {
      TreeNode clickedNode = tv.GetNodeAt(e.X, e.Y);
      if(clickedNode == node_1.1) treeView1.ContextMenu = contextMenu1;
      else if (clickedNode == node_1.2) ... and so on   }
   }

private void treeView1_MouseUp(object sender, System.Windows.Forms.MouseEventArgs e)		
{
	if(e.Button == MouseButtons.Right) 
 	{ 
        	System.EventArgs a = new EventArgs();
		Point ClickPoint = new Point(e.X,e.Y); 
		TreeNode ClickNode = treeView1.GetNodeAt(ClickPoint); 
		ruletree.SelectedNode=ClickNode;
		if(ClickNode == null) return; 
		// Convert from Tree coordinates to Screen coordinates 
		Point ScreenPoint = ruletree.PointToScreen(ClickPoint); 
		// Convert from Screen coordinates to Formc coordinates 
		Point FormPoint = this.PointToClient(ScreenPoint); 
		// Making menu Items---
		ContextMenu treeRCMenu = new ContextMenu();
		//name menu items
                MenuItem mnuRenamePNode = new MenuItem("Rename Node");
		// Show context menu 
           if(clickedNode == node_1.1) 
             {
               treeView1.ContextMenu = contextMenu1; 
             }
     else if (clickedNode == node_1.2) ... and so on   }

	}

MenuItem mnuRenamePNode = new MenuItem("Rename Parent Node");
  MenuItem mnuRenameCNode = new MenuItem("Rename Child Node");
//....code
  mnuRenamePNode.Click +=new EventHandler(mnuRenamePNode_Click);
  mnuRenameCNode.Click +=new EventHandler(mnuRenameCNode_Click);
//..etc

using System;
using System.Runtime.InteropServices;

[
  GuidAttribute("4657278A-411B-11d2-839A-00C04FD918D0"),
  ClassInterface(ClassInterfaceType.None),
  ComImport
]
public class DragDropHelper : IDropTargetHelper, IDragSourceHelper
{
}

[
  GuidAttribute("4657278B-411B-11d2-839A-00C04FD918D0"),
  InterfaceType(ComInterfaceType.InterfaceIsIUnknown),
  ComImport
]
public interface IDropTargetHelper
{
}

[
  GuidAttribute("DE5BF786-477A-11d2-839D-00C04FD918D0"),
  InterfaceType(ComInterfaceType.InterfaceIsIUnknown),
  ComImport
]
public interface IDragSourceHelper
{
}

class Test
{
  static void Main()
  {
    DragDropHelper helper = new DragDropHelper();

    IDropTargetHelper dropHelper = (IDropTargetHelper)helper;
    IDragSourceHelper dragHelper = (IDragSourceHelper)helper;

    Console.WriteLine(dropHelper == null);
    Console.WriteLine(dragHelper == null);
  }
}

private void button_Click(object sender, EventArgs e)
{
    OtherWindow other = new OtherWindow();
    other.Show();
}

if(string == "something"){ }

string s = "Nick";
if(string.Compare(s, "Nick") == 0)
    {
    //...
    }