RSS阅读器制作之TreeView树节点移动操作的实现

王朝other·作者佚名 2006-12-04

用于在TreeView之间调整树节点位置

//开始拖动树节点

private void treeView1_ItemDrag(object sender, ItemDragEventArgs e)

...{

if (e.Button == MouseButtons .Left )

...{

DoDragDrop(e.Item, DragDropEffects.Move);

}

//检验拖放的数据是否适用于目标控件,即是否为TreeNode对象

private void treeView1_DragEnter(object sender, DragEventArgs e)

...{

if (e.Data .GetDataPresent ("System.Windows.Forms.TreeNode"))

...{

e.Effect = DragDropEffects.Move;

}

else

...{

e.Effect = DragDropEffects.None;

}

//拖放操作

private void treeView1_DragDrop(object sender, DragEventArgs e)

...{

//获得拖放中的节点

TreeNode moveNode = (TreeNode)e.Data.GetData("System.Windows.Forms.TreeNode");

//根据鼠标坐标确定要移动到的目标节点

Point pt;

TreeNode targeNode;

pt = ((TreeView)(sender)).PointToClient(new Point(e.X,e.Y));

targeNode = treeView1.GetNodeAt(pt);

//如果目标节点无子节点则添加为同级节点,反之添加到下级节点的未端

if (targeNode.Nodes.Count == 0)

...{

targeNode.Parent.Nodes.Insert(targeNode.Index, (TreeNode)moveNode.Clone());

}

else

...{

targeNode.Nodes.Insert(targeNode.Nodes .Count, (TreeNode)moveNode.Clone());

}

//展开目标节点,便于显示拖放效果

targeNode.Expand();

//移除拖放的节点

moveNode.Remove();

}