通用图片处理类CImageLibrary,预设存储JPG格式|C/S框架网

C# Code:

/// <summary>
/// 图片处理
/// </summary>
public class CImageLibrary
{
   
   /// <summary>
   /// 检查图片返回的结果
   /// </summary>
   public enum ValidateImageResult { OK, InvalidFileSize, InvalidImageSize }
   
   /// <summary>
   /// 检查图片文件大小
   /// </summary>
   /// <param name="file">图片文件</param>
   /// <param name="MAX_FILE_SIZE">最大文件大小</param>
   /// <param name="MAX_WIDTH">最大宽度</param>
   /// <param name="MAX_HEIGHT">最大高度</param>
   /// <returns>返回检查结果</returns>
   public static ValidateImageResult ValidateImage(string file, int MAX_FILE_SIZE, int MAX_WIDTH, int MAX_HEIGHT)
   {
      byte[] bs = File.ReadAllBytes(file);
      double size = (bs.Length / 1024);
      
      //大于50KB
      if (size > MAX_FILE_SIZE) return ValidateImageResult.InvalidFileSize;
      
      Image img = null;
      try
      {
         img = Image.FromFile(file);
         if (img.Width > MAX_WIDTH || img.Height > MAX_HEIGHT)
         return ValidateImageResult.InvalidImageSize;
         else
         return ValidateImageResult.OK;
      }
      finally
      {
         img.Dispose();
      }
   }
   
   /// <summary>
   /// 等比例缩放图片
   /// </summary>
   /// <param name="bitmap">原图</param>
   /// <param name="destWidth">缩放后宽度</param>
   /// <param name="destHeight">缩放后高度</param>
   /// <returns></returns>
   public static Bitmap ZoomImage(Bitmap bitmap, int destWidth, int destHeight)
   {
      try
      {
         System.Drawing.Image sourImage = bitmap;
         int width = 0, height = 0;
         
         //按比例缩放
         int sourWidth = sourImage.Width;
         int sourHeight = sourImage.Height;
         if (sourHeight > destHeight || sourWidth > destWidth)
         {
            if ((sourWidth * destHeight) > (sourHeight * destWidth))
            {
               width = destWidth;
               height = (destWidth * sourHeight) / sourWidth;
            }
            else
            {
               height = destHeight;
               width = (sourWidth * destHeight) / sourHeight;
            }
         }
         else
         {
            width = sourWidth;
            height = sourHeight;
         }
         
         Bitmap destBitmap = new Bitmap(width, height);
         //Bitmap destBitmap = new Bitmap(destWidth, destHeight);
         Graphics g = Graphics.FromImage(destBitmap);
         //g.Clear(Color.Transparent);
         g.Clear(Color.White);
         
         //设置画布的描绘质量
         g.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
         g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
         g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
         //g.DrawImage(sourImage, new Rectangle((destWidth - width) / 2, (destHeight - height) / 2, width, height), 0, 0, sourImage.Width, sourImage.Height, GraphicsUnit.Pixel);
         g.DrawImage(sourImage, new Rectangle(0, 0, width, height), 0, 0, sourImage.Width, sourImage.Height, GraphicsUnit.Pixel);
         g.Dispose();
         
         //设置压缩质量
         //System.Drawing.Imaging.EncoderParameters encoderParams = new System.Drawing.Imaging.EncoderParameters();
         //long[] quality = new long[1];
         //quality[0] = 100;
         //System.Drawing.Imaging.EncoderParameter encoderParam = new System.Drawing.Imaging.EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);
         //encoderParams.Param[0] = encoderParam;
         
         //sourImage.Dispose();
         
         return destBitmap;
      }
      catch
      {
         return bitmap;
      }
   }
   
   /// <summary>
   /// 按宽度比例缩小图片
   /// </summary>
   /// <param name="imgSource">原始图片</param>
   /// <param name="MAX_WIDTH">最大宽度</param>
   /// <returns></returns>
   public static Image ResizeImage(Image imgSource, int MAX_WIDTH, int MAX_HEIGHT)
   {
      return ZoomImage(new Bitmap(imgSource), MAX_WIDTH, MAX_HEIGHT);
   }
   
   /// <summary>
   /// 图片转换为数组
   /// </summary>
   /// <param name="imageFileName">图片文件</param>
   /// <returns></returns>
   public static byte[] GetImageBytes(string imageFileName, ImageFormat format)
   {
      Image img = Image.FromFile(imageFileName);
      byte[] bs = GetImageBytes(img, format);
      img.Dispose();
      return bs;
   }
   
   /// <summary>
   /// 图片转换为数组
   /// </summary>
   /// <param name="img">图片实例</param>
   /// <returns></returns>
   public static byte[] GetImageBytes(Image img, ImageFormat format)
   {
      if (img == null) return null;
      
      MemoryStream ms1 = new MemoryStream();
      try
      {
         img.Save(ms1, format);
         byte[] bs1 = ms1.ToArray();
         ms1.Close();
         return bs1;
      }
      catch
      {
         ms1.Close();
         return null;
      }
   }
   
   /// <summary>
   /// 数组转换为图片
   /// </summary>.
   /// <param name="bs">数组</param>
   /// <returns></returns>
   public static Image FromBytes(byte[] bs)
   {
      if (bs == null) return null;
      MemoryStream ms = null;
      try
      {
         ms = new MemoryStream(bs);
         Image returnImage = Image.FromStream(ms);
         return returnImage;
         
      }
      catch { if (ms != null) ms.Close(); return null; }
   }
   
   /// <summary>
   /// 转换为BMP格式
   /// </summary>
   /// <param name="source">原图</param>
   /// <returns>返回BMP格式的图片</returns>
   public static Image ToBMP(Image source, string outFileName)
   {
      try
      {
         source.Save(outFileName, ImageFormat.Bmp);
      }
      catch (Exception ex)
      {
         throw new Exception("原图文件流可能已关闭！\r\n" + ex.Message);
      }
      
      if (source.RawFormat == ImageFormat.Bmp)
      {
         return source as Bitmap; //BMP格式不需要转换
      }
      
      return Image.FromFile(outFileName);//加载存储的BMP文件.
      
   }
   
   /// <summary>
   /// 转换为JPG格式
   /// </summary>
   /// <param name="source">原图</param>
   /// <returns>返回JPG格式的图片</returns>
   public static Image ToJPG(Image source, string outFileName)
   {
      try
      {
         source.Save(outFileName, ImageFormat.Jpeg);
      }
      catch (Exception ex)
      {
         throw new Exception("原图文件流可能已关闭！\r\n" + ex.Message);
      }
      
      if (source.RawFormat == ImageFormat.Jpeg)
      {
         return source as Bitmap; //BMP格式不需要转换
      }
      
      return Image.FromFile(outFileName);//加载存储的BMP文件.
      
   }
   
   /// <summary>
   /// 转换为PNG格式
   /// </summary>
   /// <param name="source">原图</param>
   /// <returns>返回PNG格式的图片</returns>
   public static Image ToPNG(Image source, string outFileName)
   {
      try
      {
         source.Save(outFileName, ImageFormat.Png);
      }
      catch (Exception ex)
      {
         throw new Exception("原图文件流可能已关闭！\r\n" + ex.Message);
      }
      
      if (source.RawFormat == ImageFormat.Png)
      {
         return source as Bitmap; //BMP格式不需要转换
      }
      
      return Image.FromFile(outFileName);//加载存储的BMP文件.
      
   }
   
   /// <summary>
   /// 获取1x1像素的空图片
   /// </summary>
   /// <returns></returns>
   public static byte[] GetEmptyImageByte()
   {
      Bitmap bmp = new Bitmap(1, 1);
      return GetImageBytes(bmp, ImageFormat.Jpeg);
   }
   
}

//来源:C/S框架网(www.csframework.com) QQ:23404761