C#生成高清缩略图代码，一个C#函数模块，内含注释，后附函数参数，下面来看这个C#生成缩略图代码：

01public static void SetGoodImage(string fileName, string newFile, int maxHeight, int maxWidth,long qualitys)

02{

03 if (qualitys == 0)

04 {

05 qualitys = 80;

06 }

07 using (System.Drawing.Image img = System.Drawing.Image.FromFile(fileName))

08 {

09 System.Drawing.Imaging.ImageFormat

10 thisFormat = img.RawFormat;

11 Size newSize = NewSize(maxWidth, maxHeight, img.Width, img.Height);

12 Bitmap outBmp = new Bitmap(newSize.Width, newSize.Height);

13 Graphics g = Graphics.FromImage(outBmp);

14 // 设置画布的描绘质量

15 g.CompositingQuality = CompositingQuality.HighQuality;

16 g.SmoothingMode = SmoothingMode.HighQuality;

17 g.InterpolationMode = InterpolationMode.HighQualityBicubic;

18 g.DrawImage(img, new Rectangle(0, 0, newSize.Width, newSize.Height),

19 0, 0, img.Width, img.Height, GraphicsUnit.Pixel);

20 g.Dispose();

21 // 以下代码为保存图片时,设置压缩质量

22 EncoderParameters encoderParams = new EncoderParameters();

23 long[] quality = new long[1];

24 quality[0] = qualitys;

25 EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);

26 encoderParams.Param[0] = encoderParam;

27 //获得包含有关内置图像编码解码器的信息的ImageCodecInfo 对象.

28 ImageCodecInfo[] arrayICI = ImageCodecInfo.GetImageEncoders();

29 ImageCodecInfo jpegICI = null;

30 for (int x = 0;

31 x < arrayICI.Length;

32 x++)

33 {

34 if (arrayICI[x].FormatDescription.Equals("JPEG"))

35 {

36 jpegICI = arrayICI[x];

37 //设置JPEG编码

38 break;

39 }

40 }

41 if (jpegICI != null)

42 {

43 outBmp.Save(newFile, jpegICI, encoderParams);

44 }

45 else

46 {

47 outBmp.Save(newFile, thisFormat);

48 }

49 img.Dispose();

50 outBmp.Dispose();

51 }

52}

函数参数说明：

view sourceprint?1/// 原文件

2/// 新文件

3/// 最大高度

4/// 最大宽度

5/// 质量，如果为0，则设为80

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