C# 网络编程之webBrowser获取网页url和下载网页中图片

private void button1_Click(object sender, EventArgs e) 
{ 
    webBrowser1.Navigate(textBox1.Text.Trim());         //显示网页 
} 

<strong>//定义num记录listBox2中获取到的图片URL个数 
public int num = 0; 
//点击"获取"按钮 
private void button2_Click(object sender, EventArgs e) 
{ 
    HtmlElement html = webBrowser1.Document.Body;      //定义HTML元素 
    string str = html.OuterHtml;                       //获取当前元素的HTML代码 
    MatchCollection matches;                           //定义正则表达式匹配集合 
    //清空 
    listBox1.Items.Clear(); 
    listBox2.Items.Clear(); 
    //获取 
    try 
    {           
        //正则表达式获取<a href></a>内容url 
        matches = Regex.Matches(str, "<a href=\"([^\"]*?)\".*?>(.*?)</a>", RegexOptions.IgnoreCase); 
        foreach (Match match in matches) 
        { 
            listBox1.Items.Add(match.Value.ToString());      
        } 
        //正则表达式获取<img src=>图片url 
        matches = Regex.Matches(str, @"<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); 
        foreach (Match match in matches) 
        { 
            listBox2.Items.Add(match.Value.ToString()); 
        } 
        //记录图片总数 
        num = listBox2.Items.Count; 
    } 
    catch (Exception msg) 
    { 
        MessageBox.Show(msg.Message);    //异常处理 
    } 
}</strong> 

//点击"下载"实现下载图片 
private void button3_Click(object sender, EventArgs e) 
{ 
    string imgsrc = string.Empty;             //定义 
    //循环下载 
    for (int j = 0; j < num; j++) 
    { 
        string content = listBox2.Items[j].ToString();    //获取图片url 
        Regex reg = new Regex(@"<img.*?src=""(?<src>[^""]*)""[^>]*>", RegexOptions.IgnoreCase); 
        MatchCollection mc = reg.Matches(content);        //设定要查找的字符串 
        foreach (Match m in mc) 
        {                 
            try 
            { 
                WebRequest request = WebRequest.Create(m.Groups["src"].Value);//图片src内容 
                WebResponse response = request.GetResponse(); 
                //文件流获取图片操作 
                Stream reader = response.GetResponseStream(); 
                string path = "E://" + j.ToString() + ".jpg";        //图片路径命名  
                FileStream writer = new FileStream(path, FileMode.OpenOrCreate, FileAccess.Write); 
                byte[] buff = new byte[512]; 
                int c = 0;                                           //实际读取的字节数    
                while ((c = reader.Read(buff, 0, buff.Length)) > 0) 
                { 
                    writer.Write(buff, 0, c); 
                } 
                //释放资源 
                writer.Close(); 
                writer.Dispose(); 
                reader.Close(); 
                reader.Dispose(); 
                response.Close(); 
                //下载成功 
                listBox2.Items.Add(path + ":图片保存成功!");  
            } 
            catch (Exception msg) 
            { 
                MessageBox.Show(msg.Message); 
            } 
        } 
    } 
} 

/// <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>  
public static 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 = 0; 
    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; 
} 

/// <summary> 
/// 获得图片的路径并存放 
/// </summary> 
/// <param name="M_Content">要检索的内容</param> 
/// <returns>IList</returns> 
public static IList<string> GetPicPath(string M_Content) 
{ 
    IList<string> im = new List<string>();//定义一个泛型字符类 
    Regex reg = new Regex(@"<img.*?src=""(?<src>[^""]*)""[^>]*>", RegexOptions.IgnoreCase); 
    MatchCollection mc = reg.Matches(M_Content); //设定要查找的字符串 
    foreach (Match m in mc) 
    { 
        im.Add(m.Groups["src"].Value); 
    } 
    return im; 
}