//引用命名空间 using System.Drawing.Imaging; using System.Drawing; using System.Drawing.Drawing2D;
#region GetPicThumbnail |
/// <summary>
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/// 无损压缩图片
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/// </summary>
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/// <param name="sFile">原图片</param>
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/// <param name="dFile">压缩后保存位置</param>
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/// <param name="dHeight">高度</param>
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/// <param name="dWidth"></param>
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/// <param name="flag">压缩质量 1-100</param>
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/// <returns></returns>
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public bool GetPicThumbnail( string sFile, string dFile, int dHeight, int dWidth, int flag)
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{
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System.Drawing.Image iSource = System.Drawing.Image.FromFile(sFile);
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ImageFormat tFormat = iSource.RawFormat;
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int sW = 0, sH = 0;
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//按比例缩放
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Size tem_size = new Size(iSource.Width, iSource.Height);
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if (tem_size.Width > dHeight || tem_size.Width > dWidth) //将**改成c#中的或者操作符号
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{
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if ((tem_size.Width * dHeight) > (tem_size.Height * dWidth))
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{
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sW = dWidth;
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sH = (dWidth * tem_size.Height) / tem_size.Width;
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}
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else
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{
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sH = dHeight;
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sW = (tem_size.Width * dHeight) / tem_size.Height;
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}
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}
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else
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{
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sW = tem_size.Width;
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sH = tem_size.Height;
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}
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Bitmap ob = new Bitmap(dWidth, dHeight);
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Graphics g = Graphics.FromImage(ob);
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g.Clear(Color.WhiteSmoke);
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g.CompositingQuality = CompositingQuality.HighQuality;
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g.SmoothingMode = SmoothingMode.HighQuality;
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g.InterpolationMode = InterpolationMode.HighQualityBicubic;
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g.DrawImage(iSource, new Rectangle((dWidth - sW) / 2, (dHeight - sH) / 2, sW, sH), 0, 0, iSource.Width, iSource.Height, GraphicsUnit.Pixel);
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g.Dispose();
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//以下代码为保存图片时,设置压缩质量
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EncoderParameters ep = new EncoderParameters();
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long [] qy = new long [1];
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qy[0] = flag; //设置压缩的比例1-100
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EncoderParameter eParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, qy);
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ep.Param[0] = eParam;
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try
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{
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ImageCodecInfo[] arrayICI = ImageCodecInfo.GetImageEncoders();
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ImageCodecInfo jpegICIinfo = null ;
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for ( int x = 0; x < arrayICI.Length; x++)
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{
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if (arrayICI[x].FormatDescription.Equals( "JPEG" ))
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{
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jpegICIinfo = arrayICI[x];
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break ;
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}
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}
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if (jpegICIinfo != null )
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{
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ob.Save(dFile, jpegICIinfo, ep); //dFile是压缩后的新路径
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}
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else
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{
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ob.Save(dFile, tFormat);
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}
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return true ;
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}
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catch
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{
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return false ;
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}
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finally
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{
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iSource.Dispose();
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ob.Dispose();
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}
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}
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#endregion