←Select platform

ItemDragDrop Event

Summary

Occurs when data is being dragged or dropped from/to this ImageViewer.

Syntax

C++

public event EventHandler<ImageViewerItemDragDropEventArgs> ItemDragDrop

Public Event ItemDragDrop As EventHandler(Of Leadtools.Controls.ImageViewerItemDragDropEventArgs)

public:  
   event EventHandler<Leadtools::Controls::ImageViewerItemDragDropEventArgs^>^ ItemDragDrop

Remarks

For more information refer to Image Viewer Drag and Drop.

Example

For an example on using the image viewer as the source of a drag/drop operation, refer to ImageViewerDragInteractiveMode.

This example will show how to use the ImageViewer as the drop target of a drag/drop operation.

Start with the ImageViewer example, remove all the code inside the example function (search for the "// TODO: add example code here" comment) and insert the following code:

using Leadtools; 
using Leadtools.Controls; 
using Leadtools.Codecs; 
using Leadtools.Drawing; 
using LeadtoolsExamples.Common; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Color; 
 
_imageViewer.AllowDrop = true; 
_imageViewer.BringToFront(); 
 
_imageViewer.ActiveItem = _imageViewer.Items[0]; 
 
var dragMode = new ImageViewerDragInteractiveMode(); 
dragMode.AllowedEffects = DragDropEffects.Copy | DragDropEffects.Move | DragDropEffects.Link; 
 
_imageViewer.InteractiveModes.BeginUpdate(); 
dragMode = new ImageViewerDragInteractiveMode(); 
dragMode.AllowedEffects = DragDropEffects.Copy | DragDropEffects.Move | DragDropEffects.Link; 
_imageViewer.InteractiveModes.Add(dragMode); 
_imageViewer.InteractiveModes.EndUpdate(); 
 
EventHandler<ImageViewerItemDragDropEventArgs> handler = (sender, e) => 
{ 
   switch (e.Operation) 
   { 
      case ImageViewerItemDragDropOperation.DragEnter: 
         { 
            Console.WriteLine(string.Format("DragDrop Operation:{0} {1} {2}", e.Operation, e.Effect, e.Format)); 
            Console.WriteLine(string.Format("  SrcViewer:{0} DstViewer:{1}", 
               e.SourceImageViewer != null ? e.SourceImageViewer.Name : "null", 
               e.TargetImageViewer != null ? e.TargetImageViewer.Name : "null")); 
            Console.WriteLine(string.Format("  SrcItem:{0} DstItem:{1}", 
               e.SourceItem != null ? e.SourceImageViewer.Items.IndexOf(e.SourceItem).ToString() : "null", 
               e.TargetItem != null ? e.TargetImageViewer.Items.IndexOf(e.TargetItem).ToString() : "null")); 
         } 
         break; 
 
      case ImageViewerItemDragDropOperation.DragOver: 
         { 
            Console.WriteLine(string.Format("DragDrop Operation:{0} {1} {2}", e.Operation, e.Effect, e.Format)); 
            Console.WriteLine(string.Format("  SrcViewer:{0} DstViewer:{1}", 
               e.SourceImageViewer != null ? e.SourceImageViewer.Name : "null", 
               e.TargetImageViewer != null ? e.TargetImageViewer.Name : "null")); 
            Console.WriteLine(string.Format("  SrcItem:{0} DstItem:{1}", 
               e.SourceItem != null ? e.SourceImageViewer.Items.IndexOf(e.SourceItem).ToString() : "null", 
               e.TargetItem != null ? e.TargetImageViewer.Items.IndexOf(e.TargetItem).ToString() : "null")); 
         } 
         break; 
 
      default: 
         break; 
   } 
}; 
 
_imageViewer.ItemDragDrop += handler;

Imports Leadtools 
Imports Leadtools.Controls 
Imports Leadtools.Codecs 
Imports Leadtools.Drawing 
Imports Leadtools.ImageProcessing 
Imports Leadtools.ImageProcessing.Color 
Imports LeadtoolsControlsExamples.LeadtoolsExamples.Common 
 
_imageViewer.AllowDrop = True 
_imageViewer.BringToFront() 
 
_imageViewer.ActiveItem = _imageViewer.Items(0) 
 
Dim dragMode As New ImageViewerDragInteractiveMode() 
dragMode.AllowedEffects = DragDropEffects.Copy Or DragDropEffects.Move Or DragDropEffects.Link 
 
_imageViewer.InteractiveModes.BeginUpdate() 
dragMode = New ImageViewerDragInteractiveMode() 
dragMode.AllowedEffects = DragDropEffects.Copy Or DragDropEffects.Move Or DragDropEffects.Link 
_imageViewer.InteractiveModes.Add(dragMode) 
_imageViewer.InteractiveModes.EndUpdate() 
 
Dim handler As EventHandler(Of ImageViewerItemDragDropEventArgs) = 
Sub(sender, e) 
   Select Case e.Operation 
      Case ImageViewerItemDragDropOperation.DragEnter 
         Console.WriteLine(String.Format("DragDrop Operation:{0} {1} {2}", e.Operation, e.Effect, e.Format)) 
         If Not e.SourceImageViewer Is Nothing Then 
            If Not e.TargetImageViewer Is Nothing Then 
               Console.WriteLine(String.Format("  SrcViewer:{0} DstViewer:{1}", e.SourceImageViewer.Name, e.TargetImageViewer.Name)) 
            Else 
               Console.WriteLine(String.Format("  SrcViewer:{0} DstViewer:{1}", e.SourceImageViewer.Name, "null")) 
            End If 
         Else 
            If Not e.TargetImageViewer Is Nothing Then 
               Console.WriteLine(String.Format("  SrcViewer:{0} DstViewer:{1}", "null", e.TargetImageViewer.Name)) 
            Else 
               Console.WriteLine(String.Format("  SrcViewer:{0} DstViewer:{1}", "null", "null")) 
            End If 
         End If 
         If Not e.SourceItem Is Nothing Then 
            If Not e.TargetItem Is Nothing Then 
               Console.WriteLine(String.Format("  SrcItem:{0} DstItem:{1}", e.SourceImageViewer.Items.IndexOf(e.SourceItem).ToString(), 
                                               e.TargetImageViewer.Items.IndexOf(e.TargetItem).ToString())) 
            Else 
               Console.WriteLine(String.Format("  SrcItem:{0} DstItem:{1}", e.SourceImageViewer.Items.IndexOf(e.SourceItem).ToString(), "null")) 
            End If 
         Else 
            If Not e.TargetItem Is Nothing Then 
               Console.WriteLine(String.Format("  SrcItem:{0} DstItem:{1}", "null", e.TargetImageViewer.Items.IndexOf(e.TargetItem).ToString())) 
            Else 
               Console.WriteLine(String.Format("  SrcItem:{0} DstItem:{1}", "null", "null")) 
            End If 
         End If 
 
      Case ImageViewerItemDragDropOperation.DragOver 
         Console.WriteLine(String.Format("DragDrop Operation:{0} {1} {2}", e.Operation, e.Effect, e.Format)) 
         If Not e.SourceImageViewer Is Nothing Then 
            If Not e.TargetImageViewer Is Nothing Then 
               Console.WriteLine(String.Format("  SrcViewer:{0} DstViewer:{1}", e.SourceImageViewer.Name, e.TargetImageViewer.Name)) 
            Else 
               Console.WriteLine(String.Format("  SrcViewer:{0} DstViewer:{1}", e.SourceImageViewer.Name, "null")) 
            End If 
         Else 
            If Not e.TargetImageViewer Is Nothing Then 
               Console.WriteLine(String.Format("  SrcViewer:{0} DstViewer:{1}", "null", e.TargetImageViewer.Name)) 
            Else 
               Console.WriteLine(String.Format("  SrcViewer:{0} DstViewer:{1}", "null", "null")) 
            End If 
         End If 
         If Not e.SourceItem Is Nothing Then 
            If Not e.TargetItem Is Nothing Then 
               Console.WriteLine(String.Format("  SrcItem:{0} DstItem:{1}", e.SourceImageViewer.Items.IndexOf(e.SourceItem).ToString(), 
                                               e.TargetImageViewer.Items.IndexOf(e.TargetItem).ToString())) 
            Else 
               Console.WriteLine(String.Format("  SrcItem:{0} DstItem:{1}", e.SourceImageViewer.Items.IndexOf(e.SourceItem).ToString(), "null")) 
            End If 
         Else 
            If Not e.TargetItem Is Nothing Then 
               Console.WriteLine(String.Format("  SrcItem:{0} DstItem:{1}", "null", e.TargetImageViewer.Items.IndexOf(e.TargetItem).ToString())) 
            Else 
               Console.WriteLine(String.Format("  SrcItem:{0} DstItem:{1}", "null", "null")) 
            End If 
         End If 
 
      Case Else 
   End Select 
End Sub 
 
AddHandler _imageViewer.ItemDragDrop, handler

Event Data

Parameter	Type	Description
sender	object	The source of the event.
e	ImageViewerItemDragDropEventArgs	The event data.

Requirements

Target Platforms

Reference

ImageViewer Class

ImageViewer Members

Leadtools.Controls Namespace

Help Version 19.0.2017.10.27

Leadtools.Controls.WinForms Assembly

Introduction

Getting Started

Namespaces

Leadtools.Controls Namespace

Assemblies