c# winform TreeView与ListView的项互相拖动的应用

很久没写教程了，停顿了有两年之久了。今天我们来讨论讨论
winform 中TreeView与ListView，通观两者很相似，只是一个是树形结构，一个是列表结构。

今天自己创建的群里（2175832）有个朋友问到ListView的项如何拖动到TreeView中，并生成子节点，签于麻烦，我回答比较麻烦，用BUTTON实现吧，但他觉得拖动比较方便，那当然哦！无奈帮人帮到底，送佛送到西，于是立即创建本地WINFORM 测试项目，给了点代码给他（其实他本身已经完成了一半代码量了，只是在ListView拖动项到控区域外遇到了不解之疑）

好了，废话不多说了，直接转正题吧。今天我帖了代码是两个功能的结合：

1、ListView项拖动到TreeView

2、TreeView节点项拖动到ListView中

（效果图）

主要代码实现如下：

#region 将LISTVIEW项拖动TREEVIEW中

/// <summary>

/// 对选中项指定Move的“开始拖动操作”

/// </summary>

/// <param name="sender"></param>

/// <param name="e"></param>

private void listView1_ItemDrag(object sender, System.Windows.Forms.ItemDragEventArgs e)

{

this.DoDragDrop(e.Item,DragDropEffects.Move);

}

private void listView1_DragEnter(object sender, System.Windows.Forms.DragEventArgs e)

{

e.Effect=DragDropEffects.Move;

}

private void treeView1_DragEnter(object sender, System.Windows.Forms.DragEventArgs e)

{

//判定是否现在拖动的数据是LISTVIEW项

ListViewItem lvi = (ListViewItem)e.Data.GetData(typeof(ListViewItem));

if (lvi != null)

{

e.Effect = DragDropEffects.Move;

}

else

Cursor = Cursors.No;

}

private void treeView1_DragDrop(object sender, System.Windows.Forms.DragEventArgs e)

{

//获得拖放中的项

ListViewItem lvi = (ListViewItem)e.Data.GetData(typeof(ListViewItem));

//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 = this.treeView1.GetNodeAt(pt);

TreeNode NewMoveNode =new TreeNode(lvi.Text);

if(targeNode!=null)//如果目标节点未选中，则添加到一级节点

{

targeNode.Nodes.Add(NewMoveNode);

//更新当前拖动的节点选择

treeView1.SelectedNode = NewMoveNode;

//展开目标节点,便于显示拖放效果

targeNode.Expand();

treeView1.Refresh();

}

else

{

this.treeView1.Nodes.Add(NewMoveNode);

//更新当前拖动的节点选择

treeView1.SelectedNode = NewMoveNode;

//展开目标节点,便于显示拖放效果

treeView1.ExpandAll();

treeView1.Refresh();

}

}

#endregion

#region 将treeView的项拖动到ListView

//定义被选择的项

private TreeNode _selectednode;

/// <summary>

/// 选择treeView的项

/// </summary>

/// <param name="sender"></param>

/// <param name="e"></param>

private void treeView2_AfterSelect(object sender, System.Windows.Forms.TreeViewEventArgs e)

{

try

{

_selectednode = e.Node;

}

catch { }

}

/// <summary>

/// 对选中项指定Move的“开始拖动操作”

/// </summary>

/// <param name="sender"></param>

/// <param name="e"></param>

private void treeView2_ItemDrag(object sender, System.Windows.Forms.ItemDragEventArgs e)

{

this.DoDragDrop(_selectednode,DragDropEffects.Move);

}

private void treeView2_DragEnter(object sender, System.Windows.Forms.DragEventArgs e)

{

e.Effect=DragDropEffects.Move;

}

/// <summary>

/// 添加MouseDown是因为,MouseDown先执行AfterSelect，所以在没有AfterSelect时，MouseDown要先选中被选取项

/// </summary>

/// <param name="sender"></param>

/// <param name="e"></param>

private void treeView2_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)

{

try

{

if ((e.Button & MouseButtons.Left) == MouseButtons.Left)

{

_selectednode = treeView2.GetNodeAt(e.X,e.Y);

treeView2.SelectedNode = _selectednode;

}

}

catch { }

}

private void FillListView(TreeNodeCollection nodes)

{

for (int i = 0; i < nodes.Count; i++)

{

ListViewItem lvwItem = new ListViewItem(nodes[i].Text, nodes[i].ImageIndex);

lvwItem.Tag = nodes[i].Tag;

listView2.Items.Add(lvwItem);

}

}

//当选中项移到listView的工作区时，指定被拖动的目标的移动方式

private void listView2_DragEnter(object sender, System.Windows.Forms.DragEventArgs e)

{

try

{

TreeNode node = (TreeNode)e.Data.GetData(typeof(TreeNode));

if (node != null)

{

e.Effect = DragDropEffects.Move;

}

else

Cursor = Cursors.No;

}

catch { }

finally { Cursor = Cursors.Default; }

}

//当选中项在listView在随SHU标移动时，指定被拖动的目标的移动方式

private void listView2_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e)

{

try

{

if (_selectednode != null & (e.Button & MouseButtons.Left) == MouseButtons.Left)

{

DragDropEffects dropEffect = listView2.DoDragDrop(_selectednode, DragDropEffects.Move);

}

}

catch { }

}

//当被放入控件时

private void listView2_DragDrop(object sender, System.Windows.Forms.DragEventArgs e)

{

try

{

TreeNode node = (TreeNode)e.Data.GetData(typeof(TreeNode));

if (node != null)

listView2.Items.Add(node.Text, node.ImageIndex);

}

catch { }

finally { Cursor = Cursors.Default; }

}

#endregion