1) 如何使用 Drag&Drop 移动 ListView 中的项目？我已经为从目录中拖动的文件实现了 D&D 副本。
2) 顺便说一句，你如何通过 D&D 获取到 ListView 的目录链接，我见过通过 D&D 从 Windows 资源管理器的地址栏中获取目录路径的应用程序。
private void lvwFiles_DragEnter(object sender, DragEventArgs e)
{
if (e.Data.GetDataPresent(DataFormats.FileDrop))
e.Effect = DragDropEffects.Copy;
else
e.Effect = DragDropEffects.None;
}
private void lvwFiles_DragDrop(object sender, DragEventArgs e)
{
if (e.Data.GetDataPresent(DataFormats.FileDrop))
{
var paths = (string[])e.Data.GetData(DataFormats.FileDrop);
var path = Path.GetDirectoryName(paths[0]);
paths = Media.FilterPaths(paths);
lvwFilesAdd(path, paths);
lvwFilesWrite();
}
}
找到这个@Microsoft（VS2005； http: //support.microsoft.com/kb/822483），我试图理解这段代码并让它在我的程序中工作。我将了解如何将其与 DragEnter 和 DragDrop 事件处理程序中已有的代码分开。
//lvwFiles_ItemDrag event handler
//
//Begins a drag-and-drop operation in the ListView control.
lvwFiles.DoDragDrop(lvwFiles.SelectedItems, DragDropEffects.Move);
//lvwFiles_DragEnter event handler
//
int len=e.Data.GetFormats().Length-1 ;
int i;
for (i = 0 ; i<=len ;i++)
{
if (e.Data.GetFormats()[i].Equals("System.Windows.Forms.ListView+SelectedListViewItemCollection"))
{
//The data from the drag source is moved to the target.
e.Effect = DragDropEffects.Move;
}
}
//lvwFiles_DragDrop event handler
//
//Return if the items are not selected in the ListView control.
if(lvwFiles.SelectedItems.Count==0)
{
return;
}
//Returns the location of the mouse pointer in the ListView control.
Point cp = lvwFiles.PointToClient(new Point(e.X, e.Y));
//Obtain the item that is located at the specified location of the mouse pointer.
ListViewItem dragToItem = lvwFiles.GetItemAt(cp.X, cp.Y);
if(dragToItem==null)
{
return;
}
//Obtain the index of the item at the mouse pointer.
int dragIndex = dragToItem.Index;
ListViewItem[] sel=new ListViewItem [lvwFiles.SelectedItems.Count];
for(int i=0; i<=lvwFiles.SelectedItems.Count-1;i++)
{
sel[i]=lvwFiles.SelectedItems[i];
}
for(int i=0; i<sel.GetLength(0);i++)
{
//Obtain the ListViewItem to be dragged to the target location.
ListViewItem dragItem = sel[i];
int itemIndex = dragIndex;
if(itemIndex==dragItem.Index)
{
return;
}
if(dragItem.Index<itemIndex)
itemIndex++;
else
itemIndex=dragIndex+i;
//Insert the item at the mouse pointer.
ListViewItem insertItem = (ListViewItem)dragItem.Clone();
lvwFiles.Items.Insert(itemIndex, insertItem);
//Removes the item from the initial location while
//the item is moved to the new location.
lvwFiles.Items.Remove(dragItem);
}
