C# 根据URL返回HTML_根据URL获取图片信息/缩略图

/// <summary>

/// 根据URL 返回HTML

/// </summary>

private List<string> GetHtmlByUrl(string Url)

{

WebClient client = new WebClient();

byte[] page = client.DownloadData(Url);

string content = System.Text.Encoding.UTF8.GetString(page);

List<string> _list = GetImgUrlByHtmlText(content);

return _list;

}

/---------------------根据URL--获取图片信息--------------/

//后缀名

string _suffix = _imgurls[i].Substring(_imgurls[i].Length - );

//图片文件名

string _imageInputTitle = "云鼎宝贝" + DateTime.Now.ToString("yyyyMMddhhmmss" + i) + _suffix;

System.Net.HttpWebRequest webRequest = (System.Net.HttpWebRequest)System.Net.WebRequest.Create(_imgurls[i]);

webRequest.Method = "GET";

System.Net.HttpWebResponse webResponse = (System.Net.HttpWebResponse)webRequest.GetResponse();

//获取图片保存到流

System.IO.Stream _stream = webResponse.GetResponseStream();

//保存到图片

System.Drawing.Image _image = System.Drawing.Image.FromStream(_stream);

// int _picwidth = _imgWidth.Length <= 0 ? _image.Width : Convert.ToInt32(_imgWidth);

// int _picheight = _imgHeight.Length <= 0 ? _image.Height : Convert.ToInt32(_imgHeight);

//根据参数形成缩略图

//_image = _image.GetThumbnailImage(_image.Width, _image.Height, null, IntPtr.Zero);

//实例化MemoryStream

System.IO.MemoryStream _ImageMem = new System.IO.MemoryStream();

//实例化图片格式

//ImageFormat _imgFormat = new ImageFormat(new Guid());

//根据图片后缀名判断类型.

// if (_suffix.ToLower().Equals(".jpg")) _imgFormat = ImageFormat.Jpeg;

// if (_suffix.ToLower().Equals(".png")) _imgFormat = ImageFormat.Png;

// if (_suffix.ToLower().Equals(".gif")) _imgFormat = ImageFormat.Gif;

//保存

_image.Save(_ImageMem, _image.RawFormat);

//转换为字节流

byte[] _ImageBytes = _ImageMem.GetBuffer();

//释放资源

_image.Dispose();

//关闭流

_stream.Close();

/------------图片生成缩略图--------------?

#region  生成缩略图

  ///<summary>

  /// 生成缩略图

  /// </summary>

  /// <param name="originalImagePath">源图路径（物理路径）</param>

  /// <param name="thumbnailPath">缩略图路径（物理路径）</param>

  /// <param name="width">缩略图宽度</param>

  /// <param name="height">缩略图高度</param>

  /// <param name="mode">生成缩略图的方式</param>

  public  void MakeThumbnail(string originalImagePath,  string thumbnailPath, int width, int height, string mode out string outthumbnailPath)

  {

   System.Drawing.Image originalImage =System.Drawing.Image.FromFile(originalImagePath);

   int towidth = width;

   int toheight = height;

   int x = ;

   int y = ;

   int ow = originalImage.Width;

   int oh = originalImage.Height;

   switch (mode)

   {

    case "HW"://指定高宽缩放（可能变形）

     break;

    case "W"://指定宽，高按比例

     toheight = originalImage.Height * width/originalImage.Width;

     break;

    case "H"://指定高，宽按比例

     towidth = originalImage.Width * height/originalImage.Height;

     break;

    case "Cut"://指定高宽裁减（不变形）

     if((double)originalImage.Width/(double)originalImage.Height > (double)towidth/(double)toheight)

     {

      oh = originalImage.Height;

      ow = originalImage.Height*towidth/toheight;

      y = ;

      x = (originalImage.Width - ow)/;

     }

     else

     {

      ow = originalImage.Width;

      oh = originalImage.Width*height/towidth;

      x = ;

      y = (originalImage.Height - oh)/;

     }

     break;

    default :

     break;

   }

   //新建一个bmp图片

   System.Drawing.Image bitmap = new System.Drawing.Bitmap(towidth,toheight);

   //新建一个画板

   Graphics g = System.Drawing.Graphics.FromImage(bitmap);

   //设置高质量插值法

   g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;

   //设置高质量,低速度呈现平滑程度

   g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

   //清空画布并以透明背景色填充

   g.Clear(Color.Transparent);

   //在指定位置并且按指定大小绘制原图片的指定部分

   g.DrawImage(originalImage, new Rectangle(, , towidth, toheight),

    new Rectangle(x, y, ow,oh),

    GraphicsUnit.Pixel);

   try

   {

    //以jpg格式保存缩略图

    bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg);

    outthumbnailPath=thumbnailPath;

   }

   catch(System.Exception e)

   {

    throw e;

   }

   finally

   {

    originalImage.Dispose();

    bitmap.Dispose();

    g.Dispose();

   }

  }