Csharp/C Sharp by API/System.Windows.Forms/DragEventArgs

DragEventArgs.Data.GetData

<source lang="csharp">

using System; using System.Drawing; using System.Drawing.Imaging; using System.IO; using System.Windows.Forms; class ImageDrop : Form {

   bool bIsTarget;
   Image image;
   public static void Main() {
       Application.Run(new ImageDrop());
   }
   public ImageDrop() {
       AllowDrop = true;
   }
   protected override void OnDragOver(DragEventArgs dea) {
       if (dea.Data.GetDataPresent(DataFormats.FileDrop) || dea.Data.GetDataPresent(typeof(Metafile)) || dea.Data.GetDataPresent(typeof(Bitmap))) {
           if ((dea.AllowedEffect & DragDropEffects.Move) != 0)
               dea.Effect = DragDropEffects.Move;
           if (((dea.AllowedEffect & DragDropEffects.Copy) != 0) && ((dea.KeyState & 0x08) != 0))    // Ctrl key
               dea.Effect = DragDropEffects.Copy;
       }
   }
   protected override void OnDragDrop(DragEventArgs dea) {
       if (dea.Data.GetDataPresent(DataFormats.FileDrop)) {
           string[] astr = (string[])dea.Data.GetData(DataFormats.FileDrop);
           image = Image.FromFile(astr[0]);
           Invalidate();
       } else {
           if (dea.Data.GetDataPresent(typeof(Metafile)))
               image = (Image)dea.Data.GetData(typeof(Metafile));
           else if (dea.Data.GetDataPresent(typeof(Bitmap)))
               image = (Image)dea.Data.GetData(typeof(Bitmap));
           bIsTarget = true;
           Invalidate();
       }
   }
   protected override void OnMouseDown(MouseEventArgs mea) {
       if (image != null) {
           bIsTarget = false;
           DragDropEffects dde = DoDragDrop(image,DragDropEffects.Copy | DragDropEffects.Move);
           if (dde == DragDropEffects.Move && !bIsTarget)
               image = null;
       }
   }

}

 </source>

DragEventArgs.Data.GetDataPresent

<source lang="csharp">

using System; using System.Drawing; using System.Drawing.Imaging; using System.IO; using System.Windows.Forms; class ImageDrop : Form {

   bool bIsTarget;
   Image image;
   public static void Main() {
       Application.Run(new ImageDrop());
   }
   public ImageDrop() {
       AllowDrop = true;
   }
   protected override void OnDragOver(DragEventArgs dea) {
       if (dea.Data.GetDataPresent(DataFormats.FileDrop) || dea.Data.GetDataPresent(typeof(Metafile)) || dea.Data.GetDataPresent(typeof(Bitmap))) {
           if ((dea.AllowedEffect & DragDropEffects.Move) != 0)
               dea.Effect = DragDropEffects.Move;
           if (((dea.AllowedEffect & DragDropEffects.Copy) != 0) && ((dea.KeyState & 0x08) != 0))    // Ctrl key
               dea.Effect = DragDropEffects.Copy;
       }
   }
   protected override void OnDragDrop(DragEventArgs dea) {
       if (dea.Data.GetDataPresent(DataFormats.FileDrop)) {
           string[] astr = (string[])dea.Data.GetData(DataFormats.FileDrop);
           image = Image.FromFile(astr[0]);
           Invalidate();
       } else {
           if (dea.Data.GetDataPresent(typeof(Metafile)))
               image = (Image)dea.Data.GetData(typeof(Metafile));
           else if (dea.Data.GetDataPresent(typeof(Bitmap)))
               image = (Image)dea.Data.GetData(typeof(Bitmap));
           bIsTarget = true;
           Invalidate();
       }
   }
   protected override void OnMouseDown(MouseEventArgs mea) {
       if (image != null) {
           bIsTarget = false;
           DragDropEffects dde = DoDragDrop(image,DragDropEffects.Copy | DragDropEffects.Move);
           if (dde == DragDropEffects.Move && !bIsTarget)
               image = null;
       }
   }

}

 </source>