TreeView Drag And Drop
/*
User Interfaces in C#: Windows Forms and Custom Controls
by Matthew MacDonald
Publisher: Apress
ISBN: 1590590457
*/
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
namespace TreeViewDragAndDrop
{
/// <summary>
/// Summary description for TreeViewDragAndDrop.
/// </summary>
public class TreeViewDragAndDrop : System.Windows.Forms.Form
{
internal System.Windows.Forms.TreeView treeTwo;
internal System.Windows.Forms.Splitter Splitter1;
internal System.Windows.Forms.TreeView treeOne;
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.Container components = null;
public TreeViewDragAndDrop()
{
//
// Required for Windows Form Designer support
//
InitializeComponent();
//
// TODO: Add any constructor code after InitializeComponent call
//
}
/// <summary>
/// Clean up any resources being used.
/// </summary>
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}
#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.treeTwo = new System.Windows.Forms.TreeView();
this.Splitter1 = new System.Windows.Forms.Splitter();
this.treeOne = new System.Windows.Forms.TreeView();
this.SuspendLayout();
//
// treeTwo
//
this.treeTwo.Dock = System.Windows.Forms.DockStyle.Fill;
this.treeTwo.HideSelection = false;
this.treeTwo.ImageIndex = -1;
this.treeTwo.Location = new System.Drawing.Point(239, 0);
this.treeTwo.Name = "treeTwo";
this.treeTwo.SelectedImageIndex = -1;
this.treeTwo.Size = new System.Drawing.Size(281, 366);
this.treeTwo.TabIndex = 6;
this.treeTwo.MouseDown += new System.Windows.Forms.MouseEventHandler(this.tree_MouseDown);
this.treeTwo.DragOver += new System.Windows.Forms.DragEventHandler(this.tree_DragOver);
this.treeTwo.DragDrop += new System.Windows.Forms.DragEventHandler(this.tree_DragDrop);
//
// Splitter1
//
this.Splitter1.Location = new System.Drawing.Point(236, 0);
this.Splitter1.Name = "Splitter1";
this.Splitter1.Size = new System.Drawing.Size(3, 366);
this.Splitter1.TabIndex = 5;
this.Splitter1.TabStop = false;
//
// treeOne
//
this.treeOne.Dock = System.Windows.Forms.DockStyle.Left;
this.treeOne.HideSelection = false;
this.treeOne.ImageIndex = -1;
this.treeOne.Name = "treeOne";
this.treeOne.SelectedImageIndex = -1;
this.treeOne.Size = new System.Drawing.Size(236, 366);
this.treeOne.TabIndex = 4;
this.treeOne.MouseDown += new System.Windows.Forms.MouseEventHandler(this.tree_MouseDown);
this.treeOne.DragOver += new System.Windows.Forms.DragEventHandler(this.tree_DragOver);
this.treeOne.DragDrop += new System.Windows.Forms.DragEventHandler(this.tree_DragDrop);
//
// TreeViewDragAndDrop
//
this.AutoScaleBaseSize = new System.Drawing.Size(5, 14);
this.ClientSize = new System.Drawing.Size(520, 366);
this.Controls.AddRange(new System.Windows.Forms.Control[] {
this.treeTwo,
this.Splitter1,
this.treeOne});
this.Font = new System.Drawing.Font("Tahoma", 8.25F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
this.Name = "TreeViewDragAndDrop";
this.Text = "TreeView Drag-And-Drop";
this.Load += new System.EventHandler(this.TreeViewDragAndDrop_Load);
this.ResumeLayout(false);
}
#endregion
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.Run(new TreeViewDragAndDrop());
}
private void TreeViewDragAndDrop_Load(object sender, System.EventArgs e)
{
TreeNode node = treeOne.Nodes.Add("Fruits");
node.Nodes.Add("Apple");
node.Nodes.Add("Peach");
node.Expand();
node = treeTwo.Nodes.Add("Vegetables");
node.Nodes.Add("Tomato");
node.Nodes.Add("Eggplant");
node.Expand();
treeTwo.AllowDrop = true;
treeOne.AllowDrop = true;
}
private void tree_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
{
// Get the tree.
TreeView tree = (TreeView)sender;
// Get the node underneath the mouse.
TreeNode node = tree.GetNodeAt(e.X, e.Y);
tree.SelectedNode = node;
// Start the drag-and-drop operation with a cloned copy of the node.
if (node != null)
{
tree.DoDragDrop(node.Clone(), DragDropEffects.Copy);
}
}
private void tree_DragOver(object sender, System.Windows.Forms.DragEventArgs e)
{
// Get the tree.
TreeView tree = (TreeView)sender;
// Drag and drop denied by default.
e.Effect = DragDropEffects.None;
// Is it a valid format?
if (e.Data.GetData(typeof(TreeNode)) != null)
{
// Get the screen point.
Point pt = new Point(e.X, e.Y);
// Convert to a point in the TreeView's coordinate system.
pt = tree.PointToClient(pt);
// Is the mouse over a valid node?
TreeNode node = tree.GetNodeAt(pt);
if (node != null)
{
e.Effect = DragDropEffects.Copy;
tree.SelectedNode = node;
}
}
}
private void tree_DragDrop(object sender, System.Windows.Forms.DragEventArgs e)
{
// Get the tree.
TreeView tree = (TreeView)sender;
// Get the screen point.
Point pt = new Point(e.X, e.Y);
// Convert to a point in the TreeView's coordinate system.
pt = tree.PointToClient(pt);
// Get the node underneath the mouse.
TreeNode node = tree.GetNodeAt(pt);
// Add a child node.
node.Nodes.Add((TreeNode)e.Data.GetData(typeof(TreeNode)));
// Show the newly added node if it is not already visible.
node.Expand();
}
}
}
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