首页 随笔 乐走天涯 程序资料 评论中心 Tag 论坛 其他资源 搜索 消息中心 联系我 关于 RSS

Drag and Drop Listbox Items Without OLE - 不使用 OLE 直接拖放 ListBox Items


日期: 2007-02-26 14:00 | 联系我 | 关注我: SteemIT, Twitter, Google+

本程序实现 不使用 OLE 直接拖放 ListBox Items(Drag and Drop Listbox Items Without OLE), 如图:

作者 Ali Rafiee 的描述:

MFC has a CDragListBox that virtually does the same thing. The advantage of this class over MFC's CDragListBox is that it allows the user to insert the item at the end of the list, whereas CDragListBox does not. The concept is very simple: Keep track of the item that is being dragged, indicate where the drop will be when the user is dragging the item around, and finally, insert the item in its new location once the user releases the mouse button.

To accomplish this task, you will need to catch three messages for your listbox window: WM_LBUTTONDOWN, WM_MOUSEMOVE, and WM_LBUTTONUP. The WM_LBUTTONDOWN handler method simply initializes the drag and drop process by finding the item that the user clicked on.

示例代码:


void CDragAndDropListBox::OnLButtonDown(UINT nFlags, CPoint point)
{
   CListBox::OnLButtonDown(nFlags, point);

   //clear all the flags
   m_MovingIndex = LB_ERR;
   m_MoveToIndex = LB_ERR;
   m_Captured = FALSE;
   m_Interval = 0;

   BOOL Outside;
   //Find the item that they want to drag and keep track of it.
   //Later in the mouse move, we will capture the mouse if this
   //value is set.
   int Index = ItemFromPoint(point,Outside);
   if (Index != LB_ERR && !Outside)
   {
      m_MovingIndex = Index;
      SetCurSel(Index);
   }
}

void CDragAndDropListBox::OnMouseMove(UINT nFlags, CPoint point)
{
   CListBox::OnMouseMove(nFlags, point);
   if (nFlags & MK_LBUTTON)
   {
      if (m_MovingIndex != LB_ERR && !m_Captured)
      {
         SetCapture();
         m_Captured = TRUE;
      }
      BOOL Outside;
      int Index = ItemFromPoint(point,Outside);
      //if they our not on a particular item
      if (Outside)
      {
         CRect ClientRect;
         GetClientRect(&ClientRect);

         //If they are still within the listbox window, simply
         //select the last item as the drop point; else, if
         //they are outside the window, scroll the items.
         if (ClientRect.PtInRect(point))
         {
            KillTimer(TID_SCROLLDOWN);
            KillTimer(TID_SCROLLUP);
            m_Interval = 0;
            //indicates that the user wants to drop the item
            //at the end of the list
            Index = LB_ERR;
            Outside = FALSE;
         }
         else
         {
            DoTheScrolling(point,ClientRect);
         }
      }
      else
      {
         KillTimer(TID_SCROLLDOWN);
         KillTimer(TID_SCROLLUP);
         m_Interval = 0;
      }

      if (Index != m_MoveToIndex && !Outside)
      {
         DrawTheLines(Index);
      }
   }
}

void CDragAndDropListBox::OnLButtonUp(UINT nFlags, CPoint point)
{
   if (m_MovingIndex != LB_ERR && m_Captured)
   {
      KillTimer(TID_SCROLLDOWN);
      KillTimer(TID_SCROLLUP);
      m_Interval = 0;
      m_Captured = FALSE;
      ReleaseCapture();

      CRect Rect;
      GetClientRect(&Rect);
      //if they are still within the listbox window
      if (Rect.PtInRect(point))
      {
         InsertDraggedItem();
      }
      else
      {
         Invalidate();
         UpdateWindow();
      }
      m_MovingIndex = LB_ERR;
      m_MoveToIndex = LB_ERR;
   }

   CListBox::OnLButtonUp(nFlags, point);
}

// CDragDropListBoxSampleDlg dialog
class CDragDropListBoxSampleDlg : public CDialog
{
......

// Implementation
protected:
   CDragAndDropListBox  m_ListBox;

......
};

下载地址: 点此下载源代码及演示程序


 文章评论

第 1 楼  发表于 2007-02-27 10:51 | tt 的所有评论
不错.正好我有用.多谢!

第 2 楼  发表于 2008-01-24 17:57 | yina 的所有评论
真的是非常感谢
正好需要

第 3 楼  发表于 2009-03-30 12:09 | waterliy 的所有评论
拜托,我怎么就打不开啊。能下载不能打开工程,我用的VC6.0。是什么原因呢?

第 4 楼  发表于 2011-05-04 16:59 | qinyi 的所有评论
我今天下载了几个源码,非常感谢您的收集。
QQ1437725560

共有评论 4 条, 显示 4 条。

发表你的评论
如果你想针对此文发表评论, 请填写下列表单:
姓名: * 必填 (Twitter 用户可输入以 @ 开头的用户名, Steemit 用户可输入 @@ 开头的用户名)
E-mail: 可选 (不会被公开。如果我回复了你的评论,你将会收到邮件通知)
网站 / Blog: 可选
反垃圾广告: 为了防止广告机器人自动发贴, 请计算下列表达式的值:
7 x 1 + 3 = * 必填
评论内容:
* 必填
你可以使用下列标签修饰文字:
[b] 文字 [/b]: 加粗文字
[quote] 文字 [/quote]: 引用文字

 
首页 随笔 乐走天涯 猎户星 Google Earth 程序资料 程序生活 评论 Tag 论坛 资源 搜索 联系 关于 隐私声明 版权声明 订阅邮件

程序员小辉 建站于 1997 ◇ 做一名最好的开发者是我不变的理想。
Copyright © XiaoHui.com; 保留所有权利。