很久沒寫教程了，停頓了有兩年之久了。今天我們來討論討論 winform 中TreeView與ListView，通觀兩者很相似，只是一個是樹形結構，一個是列表結構。
今天自己創建的羣裏（2175832）有個朋友問到ListView的項如何拖動到TreeView中，並生成子節點，籤於麻煩，我回答比較麻煩，用BUTTON實現吧，但他覺得拖動比較方便，那當然哦！無奈幫人幫到底，送佛送到西，於是立即創建本地WINFORM 測試項目，給了點代碼給他（其實他本身已經完成了一半代碼量了，只是在ListView拖動項到控區域外遇到了不解之疑）
好了，廢話不多說了，直接轉正題吧。今天我帖了代碼是兩個功能的結合：
1、ListView項拖動到TreeView
2、TreeView節點項拖動到ListView中
（效果圖）
主要代碼實現如下：
#region 將LISTVIEW項拖動TREEVIEW中
/// <summary>
/// 對選中項指定Move的“開始拖動操作”
/// </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)
{
//判定是否現在拖動的數據是LISTVIEW項
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)
{
//獲得拖放中的項
ListViewItem lvi = (ListViewItem)e.Data.GetData(typeof(ListViewItem));
//根據鼠標座標確定要移動到的目標節點
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)//如果目標節點未選中，則添加到一級節點
{
targeNode.Nodes.Add(NewMoveNode);
//更新當前拖動的節點選擇
treeView1.SelectedNode = NewMoveNode;
//展開目標節點,便於顯示拖放效果
targeNode.Expand();
treeView1.Refresh();
}
else
{
this.treeView1.Nodes.Add(NewMoveNode);
//更新當前拖動的節點選擇
treeView1.SelectedNode = NewMoveNode;
//展開目標節點,便於顯示拖放效果
treeView1.ExpandAll();
treeView1.Refresh();
}
}
#endregion
#region 將treeView的項拖動到ListView
//定義被選擇的項
private TreeNode _selectednode;
/// <summary>
/// 選擇treeView的項
/// </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>
/// 對選中項指定Move的“開始拖動操作”
/// </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是因爲,MouseDown先執行AfterSelect，所以在沒有AfterSelect時，MouseDown要先選中被選取項
/// </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);
}
}
//當選中項移到listView的工作區時，指定被拖動的目標的移動方式
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; }
}
//當選中項在listView在隨SHU標移動時，指定被拖動的目標的移動方式
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 { }
}
//當被放入控件時
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