title: Drag and Drop forbidden on panel even though AllowDrop is set to true
body: <p>I have a panel on my form on which I have allowed drag and drop. I have written the code to <code>DragEnter</code> and <code>DragDrop</code> events and they were working fine last time I checked. But now when I drag a file over my panel I get the forbidden cursor and the events are no longer triggered. I have looked in my entire project to see if I am disabling <code>AllowDrop</code> somewhere, but I don't.</p>
  
  <p>Here are my events together with the functions they are performing:</p>
  
  <pre><code>this.pnlNoPostbagFolder.AllowDrop = true;
  
  this.pnlNoPostbagFolder.DragDrop += new System.Windows.Forms.DragEventHandler(this.pnlNoPostbagFolder_DragDrop);
  this.pnlNoPostbagFolder.DragEnter += new System.Windows.Forms.DragEventHandler(this.pnlNoPostbagFolder_DragEnter);
  
  private void pnlNoPostbagFolder_DragDrop(object sender, DragEventArgs e)
  {
      FileListDragDrop(sender, e);
  }
  
  private void pnlNoPostbagFolder_DragEnter(object sender, DragEventArgs e)
  {
      FileListDragEnter(sender, e);
  }
  
  private void FileListDragEnter(object sender, DragEventArgs e)
  {
      if (e.Data.GetDataPresent(DataFormats.FileDrop))
          e.Effect = DragDropEffects.Copy;
      else
          e.Effect = DragDropEffects.None;
  }
  
  private void FileListDragDrop(object sender, DragEventArgs e)
  {
      string[] s = (string[])e.Data.GetData(DataFormats.FileDrop, false);
      for (int i = 0; i &lt; s.Length; i++)
      {
          if (Path.GetExtension(s[i]).Equals(".csv", StringComparison.InvariantCultureIgnoreCase) || Path.GetExtension(s[i]).Equals(".sql", StringComparison.InvariantCultureIgnoreCase))
          {
              string source = s[i];
              string destination = Common.Conf.PostbagFolderLocation + "\\" + Path.GetFileName(s[i]);
              if (File.Exists(destination))
              {
                  DialogResult dr = MsgBox.Show(string.Format("A file named '{0}' already exists in the Postbag folder. Overwrite?", Path.GetFileName(s[i])), "File Exists", MsgBox.Buttons.YesNo, MsgBox.Icon.Question);
                  if (dr == DialogResult.Yes)
                  {
                      File.Copy(source, destination, true);
                      RefreshPostbagFolder();
                  }
  
              }
              File.Copy(source, destination, true);
          }
          else
              MsgBox.Show("File extension not supported", "Add File", MsgBox.Buttons.OK, MsgBox.Icon.Error);
      }
  }
  </code></pre>