C#

<br />
[StructLayout(LayoutKind.Sequential)]<br />
public struct TVITEM<br />
{<br />
public int mask;<br />
public IntPtr hItem;<br />
public int state;<br />
public int stateMask;<br />
public IntPtr pszText;<br />
public IntPtr cchTextMax;<br />
public int iImage;<br />
public int iSelectedImage;<br />
public int cChildren;<br />
public int lParam;<br />
}<br />
<br />
class myTreeNode : TreeNode<br />
{<br />
public Int32 ItemType;<br />
public const int TV_FIRST = 0x1100 ;<br />
public const int TVM_GETITEM = TV_FIRST + 62 ;	<br />
public const int TVM_SETITEM = TV_FIRST + 63 ;<br />
<br />
public Int32 item_type<br />
{<br />
  set<br />
  {<br />
	this.ItemType = value;<br />
<br />
	TVITEM item = new TVITEM();<br />
	SendMessage(this.Handle, TVM_GETITEM, new IntPtr(0), ref item);<br />
	item.lParam = value;<br />
	SendMessage(this.Handle, TVM_SETITEM, new IntPtr(0), ref item);<br />
  }<br />
  get<br />
  {<br />
	return this.ItemType;<br />
  }<br />
}<br />
<br />
[DllImport("user32.dll")]<br />
private static extern IntPtr SendMessage(<br />
		IntPtr hWnd,<br />
 		[MarshalAs(UnmanagedType.U4)] int msg,<br />
		IntPtr wParam,<br />
		ref TVITEM item);<br />
<br />

private const int TV_FIRST = 0x1100;
private const int TVM_GETITEMA = TV_FIRST + 12;
private const int TVM_GETITEMW = TV_FIRST + 62;
private const int TVM_SETITEMA = TV_FIRST + 13;
private const int TVM_SETITEMW = TV_FIRST + 63;

int msg = TVM_SETITEMA;
if (Environment.OSVersion.Platform == PlatformID.Win32NT ||
    Environment.OSVersion.Platform == PlatformID.WinCE)
  msg = TVM_SETITEMW;
// ...

using System;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Windows.Forms;

public class Test
{
  static void Main(string[] args)
  {
    using (AccessibleForm form = new AccessibleForm())
    {
      form.MoveSizeStart += new EventHandler(OnMoveSizeStart);
      form.MoveSizeEnd += new EventHandler(OnMoveSizeEnd);
      Application.Run(form);
    }
  }

  static void OnMoveSizeStart(object sender, EventArgs e)
  {
    Console.WriteLine("Move/Size has started.");
  }

  static void OnMoveSizeEnd(object sender, EventArgs e)
  {
    Console.WriteLine("Move/Size has ended.");
  }

  private class AccessibleForm : Form
  {
    private GCHandle cbHandle;
    private IntPtr hWinEventHook;
    
    public AccessibleForm()
    {
      // Create and pin the callback.
      WinEventProcCallback callback =
        new WinEventProcCallback(WinEventProc);
      cbHandle = GCHandle.Alloc(callback);

      // Register the callback.
      hWinEventHook = SetWinEventHook(
        new IntPtr(EVENT_SYSTEM_MOVESIZESTART),
        new IntPtr(EVENT_SYSTEM_MOVESIZEEND),
        IntPtr.Zero,
        (IntPtr)cbHandle,
        Process.GetCurrentProcess().Id,
        0,
        new IntPtr(1)); // WINEVENT_INCONTEXT ???
    }

    public event EventHandler MoveSizeStart;
    public event EventHandler MoveSizeEnd;

    protected override void Dispose(bool disposing)
    {
      if (hWinEventHook != IntPtr.Zero)
      {
        UnhookWinEvent(hWinEventHook);
        hWinEventHook = IntPtr.Zero;
      }

      if (cbHandle.IsAllocated)
        cbHandle.Free();

      base.Dispose(disposing);
    }

    protected virtual void OnMoveSizeStart(EventArgs e)
    {
      if (MoveSizeStart != null)
        MoveSizeStart(this, e);
    }

    protected virtual void OnMoveSizeEnd(EventArgs e)
    {
      if (MoveSizeEnd != null)
        MoveSizeEnd(this, e);
    }

    private void WinEventProc(
      IntPtr hWinEventHook,
      uint evt,
      IntPtr hwnd,
      int idObject,
      int idChild,
      uint dwEventThread,
      uint dwmsEventTime)
    {
      if (evt == EVENT_SYSTEM_MOVESIZESTART)
        OnMoveSizeStart(EventArgs.Empty);

      else if (evt == EVENT_SYSTEM_MOVESIZEEND)
        OnMoveSizeEnd(EventArgs.Empty);
    }

    private const uint EVENT_SYSTEM_MOVESIZESTART = 0x000a;
    private const uint EVENT_SYSTEM_MOVESIZEEND = 0x000b;

    private delegate void WinEventProcCallback(
      IntPtr hWinEventHook,
      uint evt,
      IntPtr hwnd,
      int idObject,
      int idChild,
      uint dwEventThread,
      uint dwmsEventTime);

    [DllImport("user32.dll")]
    private static extern IntPtr SetWinEventHook(
      [MarshalAs(UnmanagedType.SysUInt)] IntPtr eventMin,
      [MarshalAs(UnmanagedType.SysUInt)] IntPtr eventMax,
      IntPtr hmodWinEventProc,
      IntPtr lpfnWinEventProc,
      [MarshalAs(UnmanagedType.U4)] int idProcess,
      [MarshalAs(UnmanagedType.U4)] int idThread,
      [MarshalAs(UnmanagedType.SysUInt)] IntPtr dwflags);

    [DllImport("user32.dll")]
    private static extern bool UnhookWinEvent(IntPtr hWinEventHook);
  }
}

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