| 标题 | C#图片压缩、生成缩略图、添加水印模块 |
| 范文 | C#图片处理工具类，可以压缩JPG图像，图片自动生成缩略图，为图片添加水印效果等，返回高清缩略图，得到最佳的图片比例缩放尺寸，并获取图片类型等，类代码如下： view sourceprint?001using System; 002using System.Collections.Generic; 003using System.Linq; 004using System.Text; 005using System.IO; 006using System.Drawing; 007using System.Drawing.Drawing2D; 008using System.Drawing.Imaging; 009namespace CLB.Utility.Tools 010{ 011 /// 012 /// 图片工具类 013 /// 014 public static class ImageHelper 015 { 016 /// 017 /// 压缩JPG图片 018 /// 019 /// 压缩后图片存放的地址 020 /// 需要压缩的图片地址 021 /// 压缩质量：如果为0则默认调整为80 022 public static void SetCompressImage(string NewfileName, string OldfileName, long quality) 023 { 024 if (quality == 0) 025 { 026 quality = 80; 027 } 028 using (Bitmap bitmp = new Bitmap(OldfileName)) 029 { 030 EncoderParameters ep = new EncoderParameters(1); 031 ep.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality); 032 ImageCodecInfo myImageCodecInfo = GetEncoderInfo("image/jpeg"); 033 bitmp.Save(NewfileName, myImageCodecInfo, ep); 034 bitmp.Dispose(); 035 } 036 } 037 /// 038 /// 返回高清缩略图 039 /// 040 /// 原文件 041 /// 新文件 042 /// 最大高度 043 /// 最大宽度 044 /// 质量，如果为0，则设为80 045 public static void SetGoodImage(string fileName, string newFile, int maxHeight, int maxWidth,longqualitys) 046 { 047 if (qualitys == 0) 048 { 049 qualitys = 80; 050 } 051 using (System.Drawing.Image img = System.Drawing.Image.FromFile(fileName)) 052 { 053 System.Drawing.Imaging.ImageFormat 054 thisFormat = img.RawFormat; 055 Size newSize = NewSize(maxWidth, maxHeight, img.Width, img.Height); 056 Bitmap outBmp = new Bitmap(newSize.Width, newSize.Height); 057 Graphics g = Graphics.FromImage(outBmp); 058 // 设置画布的描绘质量 059 g.CompositingQuality = CompositingQuality.HighQuality; 060 g.SmoothingMode = SmoothingMode.HighQuality; 061 g.InterpolationMode = InterpolationMode.HighQualityBicubic; 062 g.DrawImage(img, new Rectangle(0, 0, newSize.Width, newSize.Height), 063 0, 0, img.Width, img.Height, GraphicsUnit.Pixel); 064 g.Dispose(); 065 // 以下代码为保存图片时,设置压缩质量 066 EncoderParameters encoderParams = new EncoderParameters(); 067 long[] quality = new long[1]; 068 quality[0] = qualitys; 069 EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality); 070 encoderParams.Param[0] = encoderParam; 071 //获得包含有关内置图像编码解码器的信息的ImageCodecInfo 对象. 072 ImageCodecInfo[] arrayICI = ImageCodecInfo.GetImageEncoders(); 073 ImageCodecInfo jpegICI = null; 074 for (int x = 0; 075 x < arrayICI.Length; 076 x++) 077 { 078 if (arrayICI[x].FormatDescription.Equals("JPEG")) 079 { 080 jpegICI = arrayICI[x]; 081 //设置JPEG编码 082 break; 083 } 084 } 085 if (jpegICI != null) 086 { 087 outBmp.Save(newFile, jpegICI, encoderParams); 088 } 089 else 090 { 091 outBmp.Save(newFile, thisFormat); 092 } 093 img.Dispose(); 094 outBmp.Dispose(); 095 } 096 } 097 // 得到到按比例最佳尺寸 098 private static Size NewSize(int maxWidth, int maxHeight, int width, int height) 099 { 100 double w = 0.0; 101 double h = 0.0; 102 double sw = Convert.ToDouble(width); 103 double sh = Convert.ToDouble(height); 104 double mw = Convert.ToDouble(maxWidth); 105 double mh = Convert.ToDouble(maxHeight); 106 if (sw < mw && sh < mh) 107 { 108 w = sw; 109 h = sh; 110 } 111 else if ((sw / sh) > (mw / mh)) 112 { 113 w = maxWidth; 114 h = (w * sh) / sw; 115 } 116 else 117 { 118 h = maxHeight; 119 w = (h * sw) / sh; 120 } 121 return new Size(Convert.ToInt32(w), Convert.ToInt32(h)); 122 } 123 /// 124 /// 得到图片类型 125 /// 126 /// 127 /// 128 private static ImageCodecInfo GetEncoderInfo(String mimeType) 129 { 130 int j; 131 ImageCodecInfo[] encoders; 132 encoders = ImageCodecInfo.GetImageEncoders(); 133 for (j = 0; j < encoders.Length; ++j) 134 { 135 if (encoders[j].MimeType == mimeType) 136 return encoders[j]; 137 } 138 return null; 139 } 140 /// 141 /// 添加水印效果 142 /// 143 /// 输入路径 144 /// 输出路径 145 /// 水印文件路径 146 /// 水印靠近图片右边的像素 147 /// 水印靠近底边的像素 148 /// 透明度 149 public static void SetWaterMark( string fileName, string newfileName,string WaterImg,int RightSpace,intBottomSpace,int LucencyPercent) 150 { 151 using (System.Drawing.Image image = System.Drawing.Image.FromFile(fileName)) 152 { 153 ImageModification wm = new ImageModification(); 154 wm.DrawedImagePath = WaterImg; //水印图片 155 wm.ModifyImagePath = fileName; //图片的路径 156 wm.RightSpace = RightSpace; //水印位置 157 wm.BottoamSpace = image.Height - BottomSpace; //水银位置 158 wm.LucencyPercent = LucencyPercent; //透明度 159 wm.OutPath = newfileName; //生成的文件名 160 wm.DrawImage(); 161 image.Dispose(); 162 } 163 } 164 } 165} 注：更多精彩文章请关注三联编程教程栏目。 |
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