分享一个C#缩略图生成类

很多时候我们上传图片，通常会对原图进行缩略图生成的处理，便于在其他地方显示，从而加快页面的加载速度。那么在C#中，我们如何来生成缩略图呢？ 下面我给大家分享一个在C#中生成缩略图的类，大家只要根据需要传入参数，调用一下方法即可完成缩略图的生成工作，十分方便。好了，不多说了，直接上代 码。

缩略图生成类代码：

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public class Thumbnail     {         private string _OrigImagePath;         private string _ThumbSavePath;         private int _Width;         private int _Height;         private bool _Stretched;         private bool _Beveled;         private bool _AutoSaveThumb;           /// <summary>         /// 图片源文件路径         /// </summary>         public string OrigImagePath         {             get { return _OrigImagePath; }             set { _OrigImagePath = value; }         }           /// <summary>         /// 缩略图存储路径         /// </summary>         public string ThumbSavePath         {             get { return _ThumbSavePath; }             set { _ThumbSavePath = value; }         }           /// <summary>         /// 缩略图宽度         /// </summary>         public int Width         {             get { return _Width; }             set { _Width = value; }         }           /// <summary>         /// 缩略图高度         /// </summary>         public int Height         {             get { return _Height; }             set { _Height = value; }         }           /// <summary>         /// 是否拉伸图片         /// </summary>         public bool Stretched         {             get { return _Stretched; }             set { _Stretched = value; }         }           /// <summary>         /// 是否使用图片边框模糊特效         /// </summary>         public bool Beveled         {             get { return _Beveled; }             set { _Beveled = value; }         }           /// <summary>         /// 是否自动保存缩略图         /// </summary>         public bool AutoSaveThumb         {             get { return _AutoSaveThumb; }             set { _AutoSaveThumb = value; }         }             public Thumbnail()         {         }           public Thumbnail(string oPath, string sPath, int width, int height, bool stretched)         {             _OrigImagePath = oPath;             _ThumbSavePath = sPath;             _Width = width;             _Height = height;             _Stretched = stretched;         }           /// <summary>         /// 获取图片的缩略图         /// </summary>         /// <returns></returns>         public Bitmap GetThumbnail()         {             Bitmap bitmapNew;             float fx, fy, f;             float widthOrig, heightOrig;             int widthTh, heightTh;               bitmapNew = new Bitmap(_OrigImagePath); //加载图片               if (!_Stretched)             {                 widthOrig = bitmapNew.Width;                 heightOrig = bitmapNew.Height;                 fx = widthOrig / _Width;                 fy = heightOrig / _Height;                   f = Math.Max(fx, fy);                 if (f < 1)                 {                     f = 1;                 }                   widthTh = (int)(widthOrig / f);                 heightTh = (int)(heightOrig / f);             }             else             {                 widthTh = _Width;                 heightTh = _Height;             }               bitmapNew = (Bitmap)bitmapNew.GetThumbnailImage(widthTh, heightTh, new Image.GetThumbnailImageAbort(ThumbnailCallback),              IntPtr.Zero);               if (_Beveled)             {                   int widTh, heTh;                 widTh = bitmapNew.Width; heTh = bitmapNew.Height;                 int BevW = 10, LowA = 0, HighA = 180, Dark = 80, Light = 255;                 // hilight color, low and high                 Color clrHi1 = Color.FromArgb(LowA, Light, Light, Light);                 Color clrHi2 = Color.FromArgb(HighA, Light, Light, Light);                 Color clrDark1 = Color.FromArgb(LowA, Dark, Dark, Dark);                 Color clrDark2 = Color.FromArgb(HighA, Dark, Dark, Dark);                   LinearGradientBrush br;                 Rectangle rectSide;                   Graphics newG = Graphics.FromImage(bitmapNew);                 Size szHorz = new Size(widTh, BevW);                 Size szVert = new Size(BevW, heTh);                 // ---- draw dark (shadow) sides first                 // draw bottom-side of bevel                 szHorz += new Size(0, 2);                 szVert += new Size(2, 0);                 rectSide = new Rectangle(new Point(0, heTh - BevW), szHorz);                 br = new LinearGradientBrush(                   rectSide, clrDark1, clrDark2, LinearGradientMode.Vertical);                 rectSide.Inflate(0, -1);                 newG.FillRectangle(br, rectSide);                 // draw right-side of bevel                 rectSide = new Rectangle(new Point(widTh - BevW, 0), szVert);                 br = new LinearGradientBrush(                   rectSide, clrDark1, clrDark2, LinearGradientMode.Horizontal);                 rectSide.Inflate(-1, 0);                 newG.FillRectangle(br, rectSide);                 // ---- draw bright (hilight) sides next                 szHorz -= new Size(0, 2); szVert -= new Size(2, 0);                 // draw top-side of bevel                 rectSide = new Rectangle(new Point(0, 0), szHorz);                 br = new LinearGradientBrush(                   rectSide, clrHi2, clrHi1, LinearGradientMode.Vertical);                 newG.FillRectangle(br, rectSide);                 // draw left-side of bevel                 rectSide = new Rectangle(new Point(0, 0), szVert);                 br = new LinearGradientBrush(                   rectSide, clrHi2, clrHi1, LinearGradientMode.Horizontal);                 newG.FillRectangle(br, rectSide);                 // dispose graphics objects and return bitmap                 br.Dispose(); newG.Dispose();               }               if (_AutoSaveThumb)             {                 SaveThumbnail(bitmapNew, _ThumbSavePath + GetUniqueThumbName());             }             return bitmapNew;         }           /// <summary>         /// 获取一个唯一的缩略图的名称         /// </summary>         /// <returns></returns>         public String GetUniqueThumbName()         {             StringBuilder sUN = new StringBuilder();             sUN.AppendFormat("Thumb_{0}_{1}x{2}",               Path.GetFileName(_OrigImagePath), _Width, _Height);             if (_Stretched) sUN.Append("_S");             if (_Beveled) sUN.Append("_B");             sUN.Append(".jpg");             return sUN.ToString();         }           /// <summary>         /// 将缩略图以jpeg格式保存         /// </summary>         public void SaveThumbnail(Bitmap bmThumb, String path)         {             bmThumb.Save(path, ImageFormat.Jpeg);         }             public bool ThumbnailCallback() { return false; }       }

调用缩略图类代码：

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string sPath = "c:\\1.jpg";  //原图路径 string dPath = "c:\\2.jpg";  //生成缩略图的路径 int width = 300;             //缩略图宽度 int height = 600;            //缩略图高度 bool stretched = false;      //是否自动拉伸，如果false则保持原来的比例，否则按width和height拉伸 Thumbnail tb = new Thumbnail(sPath, dPath, width, height, stretched); Bitmap pic = tb.GetThumbnail(); tb.SaveThumbnail(pic, dPath);

好了，就到这里，非常简单，希望对大家有所帮助