C# 抓取网页的img src带参数的图片链接,并下载

C# 抓取网页的img src带参数的图片链接,并下载

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading;
using System.Windows.Forms; namespace ImageCollection
{
public partial class Form1 : Form
{
private static string Path = AppDomain.CurrentDomain.BaseDirectory + "img";
public Form1()
{
InitializeComponent();
} private void btnshuaqu_Click(object sender, EventArgs e)
{
string url = txturl.Text.Trim();
if (string.IsNullOrEmpty(url))
{
MessageBox.Show("请输入URl");
return;
}
txtimg.AppendText("开始抓取中:\r\n");
Thread th = new Thread(() => ShuaQu(url)) { IsBackground = true };
th.Start();
} private void ShuaQu(string url)
{
DirectoryInfo di = new DirectoryInfo(Path);
if (System.IO.Directory.Exists(Path))
{
di.Delete(true);
}
System.IO.Directory.CreateDirectory(Path);
string result = WebHttp.HttpGet(url, null, );
string[] str = GetHtmlImageUrlList(result);
txtimg.Invoke(new Action(() =>
{
txtimg.AppendText("已经获取到数据!"+str.Count() + "\r\n");
}));
//建立获取网页标题正则表达式
String regex = @"<title>.+</title>"; //返回网页标题
String title = Regex.Match(result, regex).ToString();
txttitle.Invoke(new Action(() => {
txttitle.Text = Regex.Replace(title, @"[\""]+", "");
}));
foreach (string s in str)
{
Uri u = new Uri(s);
if (u.Host == "www.xxx.com")
{
Thread downimg = new Thread(() => Get_img(s)) { IsBackground = true };
downimg.Start();
txtimg.Invoke(new Action(() => {
txtimg.AppendText(s + "\r\n");
}));
}
}
txtimg.Invoke(new Action(() =>
{
txtimg.AppendText("全部抓取完成!\r\n");
}));
} public void Get_img(string imgpath)
{ string[] file = imgpath.Split('?');
string name = System.IO.Path.GetFileName(file[]);
WebClient mywebclient = new WebClient();
mywebclient.DownloadFile(imgpath, Path + @"\" + name);
//Bitmap img = null;
//HttpWebRequest req;
//HttpWebResponse res = null;
//try
//{
// System.Uri httpUrl = new System.Uri(imgpath);
// req = (HttpWebRequest)(WebRequest.Create(httpUrl));
// req.Timeout = 180000; //设置超时值10秒
// req.UserAgent = "XXXXX";
// req.Accept = "XXXXXX";
// req.Method = "GET";
// res = (HttpWebResponse)(req.GetResponse());
// img = new Bitmap(res.GetResponseStream());//获取图片流
// img.Save(Path + @"\"+name);//随机名
//} //catch (Exception ex)
//{
// string aa = ex.Message;
//}
//finally
//{
// res.Close();
//}
} /// <summary>
/// 取得HTML中所有图片的 URL。
/// </summary>
/// <param name="sHtmlText">HTML代码</param>
/// <returns>图片的URL列表</returns>
private string[] GetHtmlImageUrlList(string sHtmlText)
{
// 定义正则表达式用来匹配 img 标签
Regex regImg = new Regex(@"<img\b[^<>]*?\bsrc[\s\t\r\n]*=[\s\t\r\n]*[""']?[\s\t\r\n]*(?<imgUrl>[^\s\t\r\n""'<>]*)[^<>]*?/?[\s\t\r\n]*>", RegexOptions.IgnoreCase); // 搜索匹配的字符串
MatchCollection matches = regImg.Matches(sHtmlText);
int i = ;
string[] sUrlList = new string[matches.Count]; // 取得匹配项列表
foreach (Match match in matches)
sUrlList[i++] = match.Groups["imgUrl"].Value;
return sUrlList;
}
}
}
#region 下载图片到Image
public static Image UrlToImage(string url) {
WebClient mywebclient = new WebClient();
byte[] Bytes = mywebclient.DownloadData(url);
using (MemoryStream ms = new MemoryStream(Bytes)) {
Image outputImg = Image.FromStream(ms);
return outputImg;
}
}
#endregion
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