Quick 'DropIn' to apply DragDrop operations to a WinForms with particular attention to dragging a file into TextBox. [tags=csharp,dragdrop,csharp-extension]

DragDropFormsExtension.cs

// tfwio ;)
using System;
namespace System.Windows.Forms
{
  /// <summary>
  /// Apply DragDrop actions indirectly using delegtes or EventHandlers,
  /// or directly with Action definitions (see Example).
  /// </summary>
  /// <seealso cref="ApplyDefaultDragDrop(TextBox)"/>
  /// <example>
  /// <code><pre>
  /// this.ApplyDragDropMethod(
  ///   (sender,e)=>{
  ///     if (e.Data.GetDataPresent(DataFormats.FileDrop)) e.Effect = DragDropEffects.Copy;
  ///   },
  ///   (sender,e)=>{
  ///     if (e.Data.GetDataPresent(DataFormats.FileDrop))
  ///     {
  ///       var strFiles = (string[])e.Data.GetData(DataFormats.FileDrop);
  ///       var file = new FileInfo(strFiles[0]);
  ///       strFiles = null;
  ///       Gogo(file);
  ///     }
  ///   });</pre></code>
  /// </example>
  static class DragDropFormsExtension
  {
    /// <seealso cref="ApplyDefaultDragDrop(TextBox)"/>
    /// <example>
    /// <code><pre>
    /// this.ApplyDragDropMethod(
    ///   (sender,e)=>{
    ///     if (e.Data.GetDataPresent(DataFormats.FileDrop)) e.Effect = DragDropEffects.Copy;
    ///   },
    ///   (sender,e)=>{
    ///     if (e.Data.GetDataPresent(DataFormats.FileDrop))
    ///     {
    ///       var strFiles = (string[])e.Data.GetData(DataFormats.FileDrop);
    ///       var file = new FileInfo(strFiles[0]);
    ///       strFiles = null;
    ///       Gogo(file);
    ///     }
    ///   });</pre></code>
    /// </example>
    static public void ApplyDragDropMethod(this Control tInput, DragEventHandler TInputDragEnter, DragEventHandler TInputDragDrop)
    {
      // dragdrop
      tInput.AllowDrop = true;
      tInput.DragEnter += TInputDragEnter;
      tInput.DragDrop += TInputDragDrop;
    }

    /// <seealso cref="ApplyDragDropMethod(Control,DragEventHandler,DragEventHandler)"/>
    static public void ApplyDefaultDragDrop(this TextBox tInput)
    {
      tInput.ApplyDragDropMethod(Event_TInputDragEnter, Event_TInputDragDrop);
    }

    internal static void Event_TInputDragEnter(object sender, DragEventArgs e)
    {
      if (e.Data.GetDataPresent(DataFormats.FileDrop))
        e.Effect = DragDropEffects.Copy;
    }

    internal static void Event_TInputDragDrop(object sender, DragEventArgs e)
    {
      TextBox tInput = sender as TextBox;
      if (tInput == null)
        throw new Exception("Something went very wrong!");
      if (e.Data.GetDataPresent(DataFormats.FileDrop)) {
        string[] strFiles = (string[])e.Data.GetData(DataFormats.FileDrop);
        tInput.Text = strFiles[0];
        strFiles = null;
      }
    }
  }
}