TreeView使用

1、添加节点，实现拖拽功能

private void Form1_Load(object sender, EventArgs e)
{
TreeNode node1 = new TreeNode();
node1.Text = "test1";
TreeNode node2 = new TreeNode();
node2.Text = "test2";

TreeNode node11 = new TreeNode();
node11.Text = "test11";
TreeNode node12 = new TreeNode();
node12.Text = "test12";

TreeNode node21 = new TreeNode();
node21.Text = "test21";

node1.Nodes.Add(node11);
node1.Nodes.Add(node12);

node2.Nodes.Add(node21);

treeView1.Nodes.Add(node1);
treeView1.Nodes.Add(node2);

this.treeView1.ExpandAll();//节点全部展开显示
}

#region 实现拖拽

/// <summary>
/// 用户开始拖动节点时发生事件
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void treeView1_ItemDrag(object sender, ItemDragEventArgs e)
{
//开始拖放操作
DoDragDrop(e.Item, DragDropEffects.Move);
}

/// <summary>
/// 在将对象拖入控件的边界时发生事件
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void treeView1_DragEnter(object sender, DragEventArgs e)
{
if (e.Data.GetDataPresent(typeof(TreeNode)))
{
e.Effect = DragDropEffects.Move;
}
else
{
e.Effect = DragDropEffects.None;
}
}

/// <summary>
/// 完成拖放操作
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void treeView1_DragDrop(object sender, DragEventArgs e)
{
TreeNode myNode = null;
if (e.Data.GetDataPresent(typeof(TreeNode)))
{
myNode = (TreeNode)(e.Data.GetData(typeof(TreeNode)));
}
else
{
MessageBox.Show("error");
return;
}
Position.X = e.X;
Position.Y = e.Y;
Position = treeView1.PointToClient(Position);//记录目标节点位置
TreeNode DropNode = this.treeView1.GetNodeAt(Position); //目标节点
if (DropNode != null && DropNode.Parent != myNode && DropNode != myNode)
{
TreeNode DragNode = myNode;
myNode.Remove();
DropNode.Nodes.Add(DragNode);
}
//目标节点为根目录
if (DropNode == null)
{
TreeNode DragNode = myNode;
myNode.Remove();
treeView1.Nodes.Add(myNode);
}
}

#endregion

/// <summary>
/// 节点选中
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void treeView1_MouseDown(object sender, MouseEventArgs e)
{
treeView1.SelectedNode = this.treeView1.GetNodeAt(e.X, e.Y);
if (treeView1.SelectedNode != null)
{
lbl_SelectedNode.Text = treeView1.SelectedNode.Text;
}
}