接受树节点拖拽的listview

来源：互联网发布：80端口被系统服务占用编辑：程序博客网时间：2024/05/20 18:53

using System;
using System.Windows.Forms;
using System.Drawing;
using System.IO;
using System.Runtime.InteropServices;
namespace jy_controls
{
/// <summary>
/// jyListview 的摘要说明。
/// </summary>
public class jyListview : System.Windows.Forms.ListView
{
  public jyListview()
  {
   //
   // TODO: 在此处添加构造函数逻辑
   //

  }
  public delegate void hDragDrop(object Items);
  public event hDragDrop DragDropItem;
  protected override void OnDragEnter(System.Windows.Forms.DragEventArgs drgevent)
  {
   base.OnDragEnter(drgevent);
   if(this.AllowDrop)
   {
    drgevent.Effect = DragDropEffects.Move;
   }
  }
  protected override void WndProc(ref System.Windows.Forms.Message m)
  {

   base.WndProc (ref m);
   switch(m.Msg)
   {
    case 0x83:
//     Console.Write(m.Msg.ToString()+"/n");
//     IntPtr hDC = jy_controls.DrawA.GetWindowDC(m.HWnd);
//     System.Drawing.Graphics gs = System.Drawing.Graphics.FromHdc(hDC);
//     System.Drawing.Image image = new System.Drawing.Bitmap("jylogo.ico");
//     gs.DrawImage(image,new System.Drawing.Point(0,0));
     break;
   }
  }
  protected override void OnItemDrag(ItemDragEventArgs e)
  {
   base.OnItemDrag (e);
   DoDragDrop(e.Item, DragDropEffects.Move);
  }
  ListViewItem curDropItem = null;
  Color curColor;
  protected override void OnDragOver(DragEventArgs drgevent)
  {
   base.OnDragOver (drgevent);
   if(this.AllowDrop)
   {
    ListViewItem DropItem = this.GetItemAt(drgevent.X,drgevent.Y);
    if(drgevent.Data.GetDataPresent(typeof(ListViewItem)))
    {
     ListViewItem myItem = (ListViewItem)(drgevent.Data.GetData(typeof(ListViewItem)));
     if (DropItem != null && DropItem != myItem)
     {
      curColor       = DropItem.BackColor;
      DropItem.BackColor = Color.Red;
     }
    }
    else
    {
     if (DropItem != null)
     {
      curColor       = DropItem.BackColor;
      DropItem.BackColor = Color.Red;
     }
    }
    curDropItem        = DropItem;
    if(curDropItem != null)
    {
     curDropItem.BackColor = curColor;
    }

   }
  }

  protected override void OnDragDrop(System.Windows.Forms.DragEventArgs drgevent)
  {
   base.OnDragDrop (drgevent);

   if(this.AllowDrop)
   {
    ListViewItem DropItem = this.curDropItem;
    try
    {
     if (drgevent.Data.GetDataPresent(typeof(ListViewItem)))
     {
      ListViewItem myItem = (ListViewItem)(drgevent.Data.GetData(typeof(ListViewItem)));

      if (DropItem != null && DropItem != myItem)
      {
       if(DragDropItem != null)
       {
        this.DragDropItem(myItem);
       }
       else
       {
        ListViewItem DragItem = myItem;
        myItem.Remove();
        this.Items.Add(DragItem);
       }

      }
     }
     else if(drgevent.Data.GetDataPresent(typeof(TreeNode)))
     {
      TreeNode item = (TreeNode)drgevent.Data.GetData(typeof(TreeNode));
      if(DragDropItem != null)
      {
       this.DragDropItem(item);
      }
      else
      {
       ListViewItem litem = new ListViewItem();
       litem.Text = item.Text;
       litem.Tag = item.Tag;
       this.Items.Add(litem);
      }
     }
     else if(drgevent.Data.GetDataPresent(typeof(object)))
     {
      if(DragDropItem != null)
      {
       this.DragDropItem(drgevent.Data.GetData(typeof(object)));
      }
      else
      {
       ListViewItem litem1 = new ListViewItem();
       litem1.Text = drgevent.Data.GetData(typeof(object)).ToString();
       litem1.Tag = drgevent.Data.GetData(typeof(object));
       this.Items.Add(litem1);
      }
     }
     else
     {
      if(DragDropItem != null)
      {
       this.DragDropItem(drgevent);
      }
     }
    }
    catch{}
   }
  }

}
}