使用正则找出CSS中的图片并下载下来

使用正则找出CSS中的图片并下载下来

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Net;
using System.IO;
using System.Threading;
using System.Text.RegularExpressions;

namespace Win.Regx
{
    public partial class FrmUrl : Form
    {
        public FrmUrl()
        {
            InitializeComponent();
            Control.CheckForIllegalCrossThreadCalls = false;
        }

        private void FrmUrl_Load(object sender, EventArgs e)
        {

        }

        private void btn_Click(object sender, EventArgs e)
        {
            Thread th = new Thread(new ThreadStart(GetData));
            th.Start();
        }

        /// <summary>
        /// 读取文件，整个匹配
        /// </summary>
        private void GetData()
        {
            string dir = Application.StartupPath + "\\";
            string file = dir + "aio0806.css";
            StringBuilder sb = new StringBuilder();
            if (File.Exists(file))
            {
                StreamReader tr = new StreamReader(file, Encoding.Default);
                string content = tr.ReadToEnd();
                tr.Close();

                int i = 0;
                // 方法一：
                // Regex regex = new Regex("url\\(['\"]?\\s*[^>]+?['\"]?\\s*\\)", RegexOptions.IgnoreCase);
                // 方法二：
                Regex regex = new Regex("url\\(['\"]?\\s*(?<url>[^>]+?)['\"]?\\s*\\)", RegexOptions.IgnoreCase);
                MatchCollection matches = regex.Matches(content);

                int lastIndex = 0;
                foreach (Match match in matches)
                {
                    if (match.Index > lastIndex)
                    {
                        sb.Append(content.Substring(lastIndex, match.Index - lastIndex));
                    }
                    i++;
                    lbl.Text = string.Format("总数：{0}", i);
                    Group g = match.Groups["url"];
                    Capture c = g.Captures[0];

                    txt.AppendText(c.Value + "\r\n");
                    // 下载文件
                    //DownFile(c.Value);

                    sb.Append(string.Format("url(images/{0})", Path.GetFileName(c.Value)));

                    lastIndex = match.Index + match.Length;
                }
                if (lastIndex < content.Length)
                {
                    sb.Append(content.Substring(lastIndex, content.Length - lastIndex));
                }
            }
            txt.AppendText(sb.ToString());
            txt.AppendText("\r\n\r\n========END========");
        }

        /// <summary>
        /// 读取文件，单行匹配
        /// </summary>
        private void GetData1()
        {
            string dir = Application.StartupPath + "\\";
            string file = dir + "aio0806.css";
            if (File.Exists(file))
            {
                StreamReader tr = new StreamReader(file, Encoding.Default);
                string line = tr.ReadLine().Trim();
                StringBuilder sb = new StringBuilder();
                int i = 0;
                while (line != null && !tr.EndOfStream)
                {
                    // 分解出所有的图片文件
                    //Match m = Regex.Match(line, "url((\\s+['\"]?[^>]+?['\"]?\\s+))$");
                    Match m = Regex.Match(line, "http://([^>]+?)(.gif|.jpg)", RegexOptions.IgnoreCase);
                    while (m.Success)
                    {
                        i++;
                        lbl.Text = string.Format("总数：{0}", i);
                        string url = m.Groups[0].ToString();
                        txt.AppendText(string.Format("{0}\r\n", url));
                        DownFile(url);
                        m = m.NextMatch();
                    }

                    line = tr.ReadLine().Trim();
                }
                sb.Length = 0;

                tr.Close();
                txt.AppendText("========END========");
            }
        }

        /// <summary>
        /// 下载文件
        /// </summary>
        /// <param name="url"></param>
        private void DownFile(string url)
        {
            try
            {
                string dir = string.Format("{0}\\images\\", Application.StartupPath);
                if (!Directory.Exists(dir)) Directory.CreateDirectory(dir);
                string fileName = string.Format("{0}{1}", dir, Path.GetFileName(url));
                WebRequest req = WebRequest.Create(url);
                WebResponse res = req.GetResponse();
                Stream stream = res.GetResponseStream();
                FileStream fs = new FileStream(fileName, FileMode.OpenOrCreate);
                int l;
                byte[] buffer = new byte[1024];
                do
                {
                    l = stream.Read(buffer, 0, buffer.Length);
                    if (l > 0)
                        fs.Write(buffer, 0, l);

                } while (l > 0);

                fs.Close();
                fs.Flush();
                stream.Close();
                stream.Flush();
            }
            catch
            {
                //
            }
        }
    }
}