Drop images from IE

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

using System.Text.RegularExpressions;

namespace DropImageUrlFromIE_Src
{
  public partial class Form1 : Form
  {
    public Form1()
    {
      InitializeComponent();
    }

    private void Form1_DragEnter(object sender, DragEventArgs e)
    {
      if (e.Data.GetDataPresent("HTML Format"))
        e.Effect = DragDropEffects.Copy;
    }

    string parseBaseURL(string html)
    {
      return Regex.Match(html, @"http://.*?/", RegexOptions.IgnoreCase).Groups[0].Value;
    }

    string parseImageSrc(string html)
    {
      return Regex.Match(html, @"<img.*?src=[""'](.*?)[""'].*>", RegexOptions.IgnoreCase | RegexOptions.Singleline).Groups[1].Value;
    }

    string getHtmlFragment(string clipboardHtml)
    {
      int fragStartPos = int.Parse(Regex.Match(clipboardHtml, @"^StartFragment:(\d+)", RegexOptions.Multiline).Groups[1].Value);
      int fragEndPos = int.Parse(Regex.Match(clipboardHtml, @"^EndFragment:(\d+)", RegexOptions.Multiline).Groups[1].Value);

      return clipboardHtml.Substring(fragStartPos, fragEndPos - fragStartPos);
    }

    private void Form1_DragDrop(object sender, DragEventArgs e)
    {
      string clipboardHtml = (string)e.Data.GetData("HTML Format");
      string htmlFragment = getHtmlFragment(clipboardHtml);
      string imageSrc = parseImageSrc(htmlFragment);
      string baseURL = parseBaseURL(clipboardHtml);

      if (imageSrc.ToUpper().IndexOf("HTTP://") == 0)
        MessageBox.Show(imageSrc);
      else
        MessageBox.Show(baseURL + imageSrc.Substring(1));
    }
  }
}