DevicesServiceIntern/DevicesService/Commen/Util.cs

using DevicesService.Commen;
using System;
using System.Configuration;
using System.Diagnostics;
using System.Drawing;
using System.Drawing.Imaging;
using System.Drawing.Printing;
using System.IO;
using System.IO.Compression;
using System.Linq;
using Document = Aspose.Words.Document;

namespace DevicesService.Common
{
    public class Util
    {
        /// <summary>
        /// 文件转Base64码
        /// </summary>
        /// <param name="imagePath"></param>
        /// <returns></returns>
        public static string ConvertImageToBase64(string imagePath)
        {
            using (MemoryStream mStream = new MemoryStream())
            {
                System.Drawing.Image image = System.Drawing.Image.FromFile(filename: imagePath);
                // 保存图片到MemoryStream流中，并用相应的图片格式
                image.Save(mStream, image.RawFormat);
                // 转换图片流为字节数组
                byte[] imageBytes = mStream.ToArray();
                // 将字节数组转换为Base64字符串
                string base64String = Convert.ToBase64String(imageBytes);
                image.Dispose();
                mStream.Close();
                return base64String;
            }
        }

        /// <summary>
        /// 文件转Base64码
        /// </summary>
        /// <param name="fileLocation"></param>
        /// <returns></returns>
        public static string ImgToBase64String(string fileLocation)
        {
            MemoryStream ms = new MemoryStream();
            try
            {
                if (System.IO.File.Exists(fileLocation))
                {
                    Bitmap bmp = new Bitmap(@fileLocation);
                    BitmapFlip(90, ref bmp);
                    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();
                    bmp.Dispose();
                    File.Delete(fileLocation);
                    return Convert.ToBase64String(arr);
                }
                return "";
            }
            catch (Exception ex)
            {
                return ex.Message;
            }
            finally
            {
                ms.Close();
            }
        }

        /// <summary>
        /// 图像翻转，基于图像中心
        /// </summary>
        public static void BitmapFlip(int iFlip, ref Bitmap btDes)
        {
            switch (iFlip)
            {
                case 0:
                    break;
                case 90:
                    btDes.RotateFlip(RotateFlipType.Rotate90FlipNone);
                    break;
                case 180:
                    btDes.RotateFlip(RotateFlipType.Rotate180FlipNone);
                    break;
                case 270:
                    btDes.RotateFlip(RotateFlipType.Rotate270FlipNone);
                    break;
            }

        }

        /// <summary>
        /// 调用打印机打印
        /// </summary>
        /// <param name="PDFPath">PDF文件路径</param>
        /// <param name="PrinterName">打印机名称</param>
        public static void Print2(string docPath, string PrinterName)
        {
            Process p = new Process();
            ProcessStartInfo startInfo = new ProcessStartInfo();
            startInfo.WindowStyle = ProcessWindowStyle.Hidden;
            startInfo.UseShellExecute = true;
            startInfo.CreateNoWindow = true;
            startInfo.FileName = docPath;
            startInfo.Verb = "print";
            startInfo.Arguments = @"/p /h \" + docPath + "\"\"" + PrinterName + "\"";
            p.StartInfo = startInfo;
            p.Start();
            p.WaitForExit();
        }

        /// <summary>
        /// string 转换为 base64
        /// </summary>
        /// <returns></returns>
        public static string str2Base64(string str)
        {
            byte[] b = System.Text.Encoding.UTF8.GetBytes(str);
            string result = Convert.ToBase64String(b);
            return result;
        }

        /// <summary>
        /// base64 转换为 string
        /// </summary>
        /// <param name="data"></param>
        public static string Base64str2(string data)
        {
            byte[] c = Convert.FromBase64String(data);
            string result = System.Text.Encoding.UTF8.GetString(c);
            return result;
        }

        /// <summary>
        /// 对base64进行压缩
        /// </summary>
        /// <param name="base64Data"></param>
        /// <returns></returns>
        public static string CompressBase64(string base64Data)
        {
            byte[] data = Convert.FromBase64String(base64Data);
            byte[] compressedData;

            using (var memoryStream = new MemoryStream())
            {
                using (var gzipStream = new GZipStream(memoryStream, CompressionMode.Compress, true))
                {
                    gzipStream.Write(data, 0, data.Length);
                    gzipStream.Flush();
                    compressedData = memoryStream.ToArray();
                }
            }
            return Convert.ToBase64String(compressedData);
        }

        /// <summary>
        /// 对base64进行解压
        /// </summary>
        /// <param name="compressedBase64Data"></param>
        /// <returns></returns>
        public static string DecompressBase64(string compressedBase64Data)
        {
            byte[] data = Convert.FromBase64String(compressedBase64Data);
            byte[] decompressedData;

            using (var memoryStream = new MemoryStream(data))
            {
                using (var gzipStream = new GZipStream(memoryStream, CompressionMode.Decompress))
                {
                    using (var outputStream = new MemoryStream())
                    {
                        gzipStream.CopyTo(outputStream);
                        decompressedData = outputStream.ToArray();
                    }
                }
            }
            return Convert.ToBase64String(decompressedData);
        }

        /// <summary>
        /// 压缩图片至200 Kb以下
        /// </summary>
        /// <param name="img">图片</param>
        /// <param name="format">图片格式</param>
        /// <param name="targetLen">压缩后大小</param>
        /// <param name="srcLen">原始大小</param>
        /// <returns>压缩后的图片</returns>
        public static Image ZipImage(Image img, ImageFormat format, long targetLen, long srcLen = 0)
        {
            //设置大小偏差幅度 10kb
            const long nearlyLen = 10240;
            //内存流  如果参数中原图大小没有传递 则使用内存流读取
            var ms = new MemoryStream();
            if (0 == srcLen)
            {
                img.Save(ms, format);
                srcLen = ms.Length;
            }

            //单位 由Kb转为byte 若目标大小高于原图大小，则满足条件退出
            targetLen *= 1024;
            if (targetLen > srcLen)
            {
                ms.SetLength(0);
                ms.Position = 0;
                img.Save(ms, format);
                img = Image.FromStream(ms);
                return img;
            }

            //获取目标大小最低值
            var exitLen = targetLen - nearlyLen;

            //初始化质量压缩参数 图像 内存流等
            var quality = (long)Math.Floor(100.00 * targetLen / srcLen);
            var parms = new EncoderParameters(1);

            //获取编码器信息
            ImageCodecInfo formatInfo = null;
            var encoders = ImageCodecInfo.GetImageEncoders();
            foreach (ImageCodecInfo icf in encoders)
            {
                if (icf.FormatID == format.Guid)
                {
                    formatInfo = icf;
                    break;
                }
            }

            //使用二分法进行查找 最接近的质量参数
            long startQuality = quality;
            long endQuality = 100;
            quality = (startQuality + endQuality) / 2;

            while (true)
            {
                //设置质量
                parms.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);

                //清空内存流 然后保存图片
                ms.SetLength(0);
                ms.Position = 0;
                img.Save(ms, formatInfo, parms);

                //若压缩后大小低于目标大小，则满足条件退出
                if (ms.Length >= exitLen && ms.Length <= targetLen)
                {
                    break;
                }
                else if (startQuality >= endQuality) //区间相等无需再次计算
                {
                    break;
                }
                else if (ms.Length < exitLen) //压缩过小,起始质量右移
                {
                    startQuality = quality;
                }
                else //压缩过大 终止质量左移
                {
                    endQuality = quality;
                }

                //重新设置质量参数 如果计算出来的质量没有发生变化，则终止查找。这样是为了避免重复计算情况{start:16,end:18} 和 {start:16,endQuality:17}
                var newQuality = (startQuality + endQuality) / 2;
                if (newQuality == quality)
                {
                    break;
                }
                quality = newQuality;
                //Console.WriteLine("start:{0} end:{1} current:{2}", startQuality, endQuality, quality);
            }
            img = Image.FromStream(ms);
            return img;
        }

        /// <summary>
        ///获取图片格式
        /// </summary>
        /// <param name="img">图片</param>
        /// <returns>默认返回JPEG</returns>
        public static ImageFormat GetImageFormat(Image img)
        {
            if (img.RawFormat.Equals(ImageFormat.Jpeg))
            {
                return ImageFormat.Jpeg;
            }
            if (img.RawFormat.Equals(ImageFormat.Gif))
            {
                return ImageFormat.Gif;
            }
            if (img.RawFormat.Equals(ImageFormat.Png))
            {
                return ImageFormat.Png;
            }
            if (img.RawFormat.Equals(ImageFormat.Bmp))
            {
                return ImageFormat.Bmp;
            }
            return ImageFormat.Jpeg;//根据实际情况选择返回指定格式还是null
        }

        /// <summary>
        /// 压缩图片
        /// </summary>
        /// <param name="file"></param>
        /// <returns></returns>

        public static string CompressPictures(FileInfo file)
        {
            Image image = null;
            try
            {
                string fullpath = String.Empty;
                //获取未压缩的图片进行压缩
                if (file != null && file.Length > 0)
                {
                    if (!file.Name.Contains("_compress"))
                    {
                        //压缩图片
                        image =GetPicThumbnail(file.FullName);
                        if (image != null)
                        {
                            //压缩后的图片，图片名称增加_compress
                            string newName = file.Name.Replace(file.Extension, "") + "_compress" + file.Extension;
                            fullpath = file.FullName.Replace(file.Name, newName);
                            image.Save(fullpath);
                            file.Delete();
                        }
                    }
                    else
                    {
                        fullpath = file.FullName;
                    }
                }
                return fullpath;
            }
            catch (Exception ex)
            {
                Log.Error(file.FullName);
                Log.Error(ex.Message + "MainViewModel.CompressPictures");
                return "";
            }
            finally
            {
                if (image != null)
                    image.Dispose();
            }
        }

        /// <summary>
        /// 图片压缩
        /// </summary>
        /// <param name="sFile">图片路径</param>
        /// <param name="flag">压缩比1-100</param>
        /// <returns>返回图片对象</returns>
        public static Image GetPicThumbnail(string sFile)
        {
            int flag = Convert.ToInt32(ConfigurationManager.AppSettings["ysb"].ToString());
            Image result = null;
            if (sFile != null)
            {
                Image inputImage = Image.FromFile(sFile);
                try
                {
                    MemoryStream imgms = new MemoryStream();
                    var arrayICI = ImageCodecInfo.GetImageEncoders();
                    ImageCodecInfo jpegICIinfo = arrayICI.Where(w => w.FormatDescription.Contains("JPEG")).FirstOrDefault();
                    if (jpegICIinfo != null)
                    {            //以下代码为保存图片时，设置压缩质量         
                        var ep = new EncoderParameters()
                        {
                            Param = new EncoderParameter[]
                            {
                      new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, new long[1]{ flag})
                            }
                        };
                        inputImage.Save(imgms, jpegICIinfo, ep);
                        result = Image.FromStream(imgms);
                    }
                    return result;
                }
                catch (Exception ex)
                {
                    throw ex;
                }
                finally
                {
                    inputImage.Dispose();
                }
            }
            else
            {
                return result;
            }
        }
    }
}