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148 lines
4.8 KiB
Plaintext
148 lines
4.8 KiB
Plaintext
using System;
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using System.Drawing;
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using System.Drawing.Drawing2D;
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using System.Drawing.Imaging;
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using System.IO;
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using System.Web;
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namespace BP.Tools
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{
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/// <summary>
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/// 文件压缩类
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/// </summary>
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public class Luban
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{
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/// <summary>
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/// 文件大小
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/// </summary>
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public long ImgFileLength { get; set; }
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/// <summary>
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/// 图片文件
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/// </summary>
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public Image Img { get; set; }
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/// <summary>
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/// 忽略压缩
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/// </summary>
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public int IgnoreBy { get; set; } = 102400;
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//质量
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public int Quality { get; set; } = 60;
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public Luban(HttpPostedFile hpf)
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{
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this.Img = Image.FromStream(hpf.InputStream, true, true);
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this.ImgFileLength = hpf.ContentLength;
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}
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public Luban(HttpPostedFileBase hpf)
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{
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this.Img = Image.FromStream(hpf.InputStream, true, true);
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this.ImgFileLength = hpf.ContentLength;
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}
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public Luban(string path)
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{
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this.Img = Image.FromFile(path);
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this.ImgFileLength = new FileInfo(path).Length;
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}
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public void Compress(string outputPath)
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{
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// 先调整大小，再调整品质
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if (ImgFileLength <= this.IgnoreBy)
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{
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Resize(Img, outputPath, Img.Size.Width, Img.Size.Height, Quality);
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}
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else
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{
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var scale = ComputeScale();
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var _tup_1 = Img.Size;
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var srcWidth = _tup_1.Width;
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var srcHeight = _tup_1.Height;
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Resize(Img, outputPath, srcWidth / scale, srcHeight / scale, Quality);
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}
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}
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private int ComputeScale()
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{
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// 计算缩小的倍数
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var _tup_1 = Img.Size;
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var srcWidth = _tup_1.Width;
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var srcHeight = _tup_1.Height;
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srcWidth = srcWidth % 2 == 1 ? srcWidth + 1 : srcWidth;
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srcHeight = srcHeight % 2 == 1 ? srcHeight + 1 : srcHeight;
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var longSide = Math.Max(srcWidth, srcHeight);
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var shortSide = Math.Min(srcWidth, srcHeight);
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double scale = Convert.ToDouble(shortSide) / longSide;
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if (scale <= 1 && scale > 0.5625)
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{
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if (longSide < 1664)
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{
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return 1;
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}
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else if (longSide < 4990)
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{
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return 2;
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}
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else if (longSide > 4990 && longSide < 10240)
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{
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return 4;
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}
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else
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{
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return Math.Max(1, longSide / 1280);
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}
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}
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else if (scale <= 0.5625 && scale > 0.5)
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{
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return Math.Max(1, longSide / 1280);
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}
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else
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{
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return (int)Math.Ceiling(longSide / (1280.0 / scale));
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}
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}
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private void Resize(Image iSource, string outputPath, int newWidth, int newHeight, int quality)
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{
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ImageFormat tFormat = iSource.RawFormat;
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Bitmap ob = new Bitmap(newWidth, newHeight);
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Graphics graph = Graphics.FromImage(ob);
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graph.InterpolationMode = InterpolationMode.HighQualityBicubic;
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graph.PixelOffsetMode = PixelOffsetMode.HighQuality;
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graph.CompositingQuality = CompositingQuality.HighQuality;
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graph.SmoothingMode = SmoothingMode.AntiAlias;
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graph.DrawImage(iSource, new Rectangle(0, 0, newWidth, newHeight));
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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] = quality;//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(outputPath, 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(outputPath, tFormat);
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}
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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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}
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}
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