C#图片操作公共库
存一下,以后找起来方便
包括图片加载、压缩、base64等
public static class ImageFun { #region 图片 public static EncoderParameters GetEncoderParas(long picquality) { EncoderParameters eps = new EncoderParameters(1); Encoder ec = Encoder.Quality; EncoderParameter ep = new EncoderParameter(ec, picquality); eps.Param[0] = ep; return eps; } public static ImageCodecInfo GetJpegCodecInfo() { ImageCodecInfo[] arrayICI = ImageCodecInfo.GetImageEncoders(); ImageCodecInfo jpegICIinfo = null; for (int x = 0; x < arrayICI.Length; x++) { if (arrayICI[x].FormatDescription.Equals("JPEG")) { jpegICIinfo = arrayICI[x]; break; } } return jpegICIinfo; } public static System.Drawing.Image GetImage(string path) { FileStream fs = new FileStream(path, FileMode.Open); Image result = Image.FromStream(fs); fs.Close(); return result; } public static Bitmap GetImageFromBase64(string base64string) { byte[] b = Convert.FromBase64String(base64string); MemoryStream ms = new MemoryStream(b); Bitmap bitmap = new Bitmap(ms); return bitmap; } public static string GetBase64FromImage(string imagefile) { string strbaser64 = ""; try { Bitmap bmp = new Bitmap(imagefile); MemoryStream ms = new MemoryStream(); bmp.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg); byte[] arr = new byte[ms.Length]; ms.Position = 0; ms.Read(arr, 0, (int)ms.Length); ms.Close(); strbaser64 = Convert.ToBase64String(arr); } catch (Exception) { return ""; } return strbaser64; } /// <summary> /// 按照比例缩小图片 /// </summary> /// <param name="srcImage">要缩小的图片</param> /// <param name="percent">缩小比例</param> /// <returns>缩小后的结果</returns> public static Bitmap PercentImage(Image srcImage, double percent) { // 缩小后的高度 int newH = int.Parse(Math.Round(srcImage.Height * percent).ToString()); // 缩小后的宽度 int newW = int.Parse(Math.Round(srcImage.Width * percent).ToString()); try { // 要保存到的图片 Bitmap b = new Bitmap(newW, newH); Graphics g = Graphics.FromImage(b); // 插值算法的质量 g.InterpolationMode = InterpolationMode.Default; g.DrawImage(srcImage, new Rectangle(0, 0, newW, newH), new Rectangle(0, 0, srcImage.Width, srcImage.Height), GraphicsUnit.Pixel); g.Dispose(); return b; } catch (Exception) { return null; } } /// <summary> /// 按照指定大小缩放图片 /// </summary> /// <param name="srcImage"></param> /// <param name="iWidth"></param> /// <param name="iHeight"></param> /// <returns></returns> public static Bitmap SizeImage(Image srcImage, int iWidth, int iHeight) { try { // 要保存到的图片 Bitmap b = new Bitmap(iWidth, iHeight); Graphics g = Graphics.FromImage(b); // 插值算法的质量 g.InterpolationMode = InterpolationMode.HighQualityBicubic; g.DrawImage(srcImage, new Rectangle(0, 0, iWidth, iHeight), new Rectangle(0, 0, srcImage.Width, srcImage.Height), GraphicsUnit.Pixel); g.Dispose(); return b; } catch (Exception) { return null; } } /// <summary> /// jpeg图片压缩 /// </summary> /// <param name="sFile"></param> /// <param name="outPath"></param> /// <param name="flag"></param> /// <returns></returns> public static bool GetPicThumbnail(string sFile, string outPath, int flag) { if (File.Exists(outPath)) File.Delete(outPath); System.Drawing.Image iSource = System.Drawing.Image.FromFile(sFile); ImageFormat tFormat = iSource.RawFormat; //以下代码为保存图片时,设置压缩质量 EncoderParameters ep = new EncoderParameters(); long[] qy = new long[1]; qy[0] = flag;//设置压缩的比例1-100 EncoderParameter eParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, qy); ep.Param[0] = eParam; try { ImageCodecInfo[] arrayICI = ImageCodecInfo.GetImageEncoders(); ImageCodecInfo jpegICIinfo = null; for (int x = 0; x < arrayICI.Length; x++) { if (arrayICI[x].FormatDescription.Equals("JPEG")) { jpegICIinfo = arrayICI[x]; break; } } if (jpegICIinfo != null) { iSource.Save(outPath, jpegICIinfo, ep);//dFile是压缩后的新路径 } else { iSource.Save(outPath, tFormat); } return true; } catch { return false; } finally { iSource.Dispose(); } } #endregion }