Drag Items from a List and Drop Them on a Canvas : Drag Drop « Windows Presentation Foundation « C# / CSharp Tutorial

1. C# / CSharp Tutorial
2. Windows Presentation Foundation
3. Drag Drop

<Window x:Class="WpfApplication1.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="WPF " Height="300" Width="300">
    <DockPanel LastChildFill="True" >
        <ListBox DockPanel.Dock="Left" Name="lstLabels">
            <ListBox.Resources>
                <Style TargetType="{x:Type ListBoxItem}">
                    <EventSetter Event="PreviewMouseLeftButtonDown" Handler="ListBoxItem_PreviewMouseLeftButtonDown"/>    
                    <EventSetter Event="PreviewMouseMove" Handler="ListBoxItem_PreviewMouseMove"/>
                </Style>
            </ListBox.Resources>
            <ListBoxItem>A</ListBoxItem>
            <ListBoxItem>B</ListBoxItem>
            <ListBoxItem>C</ListBoxItem>
            <ListBoxItem>D</ListBoxItem>
            <ListBoxItem>E</ListBoxItem>
            <ListBoxItem>F</ListBoxItem>
            <ListBoxItem>G</ListBoxItem>
            <ListBoxItem>H</ListBoxItem>
        </ListBox>
        <Canvas AllowDrop="True" Background="Red"
                DragEnter="cvsSurface_DragEnter" Drop="cvsSurface_Drop" 
                Name="cvsSurface" >
        </Canvas>
    </DockPanel>
</Window>
//File:Window.xaml.cs

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;

namespace WpfApplication1
{
    public partial class Window1 : Window
    {
        private ListBoxItem draggedItem;
        private Point startDragPoint;

        public Window1()
        {
            InitializeComponent();
        }
        private void cvsSurface_DragEnter(object sender, DragEventArgs e)
        {
            if (e.Data.GetDataPresent(DataFormats.Text))
            {
                e.Effects = DragDropEffects.Copy;
            }
            else
            {
                e.Effects = DragDropEffects.None;
            }
        }
        private void cvsSurface_Drop(object sender, DragEventArgs e)
        {
            Label newLabel = new Label();
            newLabel.Content = e.Data.GetData(DataFormats.Text);

            cvsSurface.Children.Add(newLabel);
            Canvas.SetLeft(newLabel,100);
            Canvas.SetTop(newLabel, 200);
        }
        private void ListBoxItem_PreviewMouseLeftButtonDown(object sender,MouseButtonEventArgs e)
        {
            draggedItem = sender as ListBoxItem;
            startDragPoint = e.GetPosition(null);
        }
        private void ListBoxItem_PreviewMouseMove(object sender,MouseEventArgs e)
        {
            Point position = e.GetPosition(null);
            DragDrop.DoDragDrop(draggedItem, draggedItem.Content,DragDropEffects.Copy);
        }
    }
}

24.79.Drag Drop
	24.79.1.	Drag Items from a List and Drop Them on a Canvas