ASP.NET 图片上传工具类 upload image简单好用功能齐全

使用方法：

  UploadImage ui = new UploadImage();



            /***可选参数***/



            ui.SetWordWater = "哈哈";//文字水印

            // ui.SetPicWater = Server.MapPath("2.png");//图片水印(图片和文字都赋值图片有效)

            ui.SetPositionWater = 4;//水印图片的位置 0居中、1左上角、2右上角、3左下角、4右下角



            ui.SetSmallImgHeight = "110,40,20";//设置缩略图可以多个

            ui.SetSmallImgWidth = "100,40,20";



            //保存图片生成缩略图

            var reponseMessage = ui.FileSaveAs(Request.Files[0], Server.MapPath("~/file/temp"));



            //裁剪图片

            var reponseMessage2 = ui.FileCutSaveAs(Request.Files[0], Server.MapPath("~/file/temp2"), 400, 300, UploadImage.CutMode.CutNo);









            /***返回信息***/

            var isError = reponseMessage.IsError;//是否异常

            var webPath = reponseMessage.WebPath;//web路径

            var filePath = reponseMessage.filePath;//物理路径

            var message = reponseMessage.Message;//错误信息

            var directory = reponseMessage.Directory;//目录

            var smallPath1 = reponseMessage.SmallPath(0);//缩略图路径1

            var smallPath2 = reponseMessage.SmallPath(1);//缩略图路径2

            var smallPath3 = reponseMessage.SmallPath(2);//缩略图路径3

　　

 

 效果：

 

源码：

 

using System;

using System.Collections.Generic;

using System.Text;

using System.IO;

using System.Web;

using System.Drawing;

using System.Drawing.Imaging;

using System.Drawing.Drawing2D;

using System.Collections;

using System.Net;

using System.Text.RegularExpressions;

using System.Configuration;



namespace SyntacticSugar

{

    /// <summary>

    /// ** 描述：图片上传类、支持水印、缩略图

    /// ** 创始时间：2015-5-28

    /// ** 修改时间：-

    /// ** 修改人：sunkaixuan

    /// ** 使用说明：http://www.cnblogs.com/sunkaixuan/p/4536626.html

    /// </summary>

    public class UploadImage

    {



        #region 属性

        /// <summary>

        /// 允许图片格式

        /// </summary>

        public string SetAllowFormat { get; set; }

        /// <summary>

        /// 允许上传图片大小

        /// </summary>

        public double SetAllowSize { get; set; }

        /// <summary>

        /// 文字水印字符

        /// </summary>

        public string SetWordWater { get; set; }

        /// <summary>

        /// 图片水印

        /// </summary>

        public string SetPicWater { get; set; }

        /// <summary>

        /// 水印图片的位置 0居中、1左上角、2右上角、3左下角、4右下角

        /// </summary>

        public int SetPositionWater { get; set; }

        /// <summary>

        /// 缩略图宽度多个逗号格开（例如:200,100）

        /// </summary>

        public string SetSmallImgWidth { get; set; }

        /// <summary>

        /// 缩略图高度多个逗号格开（例如:200,100）

        /// </summary>

        public string SetSmallImgHeight { get; set; }

        /// <summary>

        /// 是否限制最大宽度，默认为true

        /// </summary>

        public bool SetLimitWidth { get; set; }

        /// <summary>

        /// 最大宽度尺寸，默认为600

        /// </summary>

        public int SetMaxWidth { get; set; }

        /// <summary>

        /// 是否剪裁图片，默认true

        /// </summary>

        public bool SetCutImage { get; set; }

        /// <summary>

        /// 限制图片最小宽度，0表示不限制

        /// </summary>

        public int SetMinWidth { get; set; }



        #endregion



        public UploadImage()

        {

            SetAllowFormat = ".jpeg|.jpg|.bmp|.gif|.png";   //允许图片格式

            SetAllowSize = 1;       //允许上传图片大小,默认为1MB

            SetPositionWater = 4;

            SetCutImage = true;

        }







        #region main method





        /// <summary>

        /// 裁剪图片

        /// </summary>

        /// <param name="PostedFile">HttpPostedFile控件</param>

        /// <param name="SavePath">保存路径【sys.config配置路径】</param>

        /// <param name="oImgWidth">图片宽度</param>

        /// <param name="oImgHeight">图片高度</param>

        /// <param name="cMode">剪切类型</param>

        /// <param name="ext">返回格式</param>

        /// <returns>返回上传信息</returns>

        public ResponseMessage FileCutSaveAs(System.Web.HttpPostedFile PostedFile, string SavePath, int oImgWidth, int oImgHeight, CutMode cMode)

        {

            ResponseMessage rm = new ResponseMessage();

            try

            {

                //获取上传文件的扩展名

                string sEx = System.IO.Path.GetExtension(PostedFile.FileName);

                if (!CheckValidExt(SetAllowFormat, sEx))

                {

                    TryError(rm, 2);

                    return rm;

                }



                //获取上传文件的大小

                double PostFileSize = PostedFile.ContentLength / 1024.0 / 1024.0;



                if (PostFileSize > SetAllowSize)

                {

                    TryError(rm, 3);

                    return rm;  //超过文件上传大小

                }

                if (!System.IO.Directory.Exists(SavePath))

                {

                    System.IO.Directory.CreateDirectory(SavePath);

                }

                //重命名名称

                string NewfileName = DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString() + DateTime.Now.Day.ToString() + DateTime.Now.Hour.ToString() + DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString() + DateTime.Now.Millisecond.ToString("000");

                string fName = "s" + NewfileName + sEx;

                string fullPath = Path.Combine(SavePath, fName);

                PostedFile.SaveAs(fullPath);



                //重命名名称

                string sNewfileName = DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString() + DateTime.Now.Day.ToString() + DateTime.Now.Hour.ToString() + DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString() + DateTime.Now.Millisecond.ToString("000");

                string sFName = sNewfileName + sEx;

                rm.IsError = false;

                rm.FileName = sFName;

                string sFullPath = Path.Combine(SavePath, sFName);

                rm.filePath = sFullPath;

                rm.WebPath = "/"+sFullPath.Replace(HttpContext.Current.Server.MapPath("~/"), "").Replace("\\", "/");

                CreateSmallPhoto(fullPath, oImgWidth, oImgHeight, sFullPath, SetPicWater, SetWordWater, cMode);

                if (File.Exists(fullPath))

                {

                    File.Delete(fullPath);

                }

                //压缩

                if (PostFileSize > 100)

                {

                    CompressPhoto(sFullPath, 100);

                }

            }

            catch (Exception ex)

            {

                TryError(rm, ex.Message);

            }

            return rm;

        }







        /// <summary>

        /// 通用图片上传类

        /// </summary>

        /// <param name="PostedFile">HttpPostedFile控件</param>

        /// <param name="SavePath">保存路径【sys.config配置路径】</param>

        /// <param name="finame">返回文件名</param>

        /// <param name="fisize">返回文件大小</param>

        /// <returns>返回上传信息</returns>

        public ResponseMessage FileSaveAs(System.Web.HttpPostedFile PostedFile, string SavePath)

        {

            ResponseMessage rm = new ResponseMessage();

            try

            {

                if (string.IsNullOrEmpty(PostedFile.FileName))

                {

                    TryError(rm, 4);

                    return rm;

                }



                Random rd = new Random();

                int rdInt = rd.Next(1000, 9999);

                //重命名名称

                string NewfileName = DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString() + DateTime.Now.Day.ToString() + DateTime.Now.Hour.ToString() + DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString() + DateTime.Now.Millisecond.ToString() + rdInt;



                //获取上传文件的扩展名

                string sEx = System.IO.Path.GetExtension(PostedFile.FileName);

                if (!CheckValidExt(SetAllowFormat, sEx))

                {

                    TryError(rm, 2);

                    return rm;

                }



                //获取上传文件的大小

                double PostFileSize = PostedFile.ContentLength / 1024.0 / 1024.0;



                if (PostFileSize > SetAllowSize)

                {

                    TryError(rm, 3);

                    return rm;

                }





                if (!System.IO.Directory.Exists(SavePath))

                {

                    System.IO.Directory.CreateDirectory(SavePath);

                }



                rm.FileName = NewfileName + sEx;

                string fullPath = SavePath.Trim('\\') + "\\" + rm.FileName;

                rm.WebPath = "/"+fullPath.Replace(HttpContext.Current.Server.MapPath("~/"), "").Replace("\\", "/");

                rm.filePath = fullPath;

                rm.Size = PostFileSize;

                PostedFile.SaveAs(fullPath);





                System.Drawing.Bitmap bmp = new Bitmap(fullPath);

                int realWidth = bmp.Width;

                int realHeight = bmp.Height;

                bmp.Dispose();



                #region 检测图片宽度限制

                if (SetMinWidth > 0)

                {

                    if (realWidth < SetMinWidth)

                    {

                        TryError(rm, 7);

                        return rm;

                    }

                }

                #endregion



                #region 监测图片宽度是否超过600，超过的话，自动压缩到600

                if (SetLimitWidth && realWidth > SetMaxWidth)

                {

                    int mWidth = SetMaxWidth;

                    int mHeight = mWidth * realHeight / realWidth;



                    string tempFile = SavePath + Guid.NewGuid().ToString() + sEx;

                    File.Move(fullPath, tempFile);

                    CreateSmallPhoto(tempFile, mWidth, mHeight, fullPath, "", "");

                    File.Delete(tempFile);

                }

                #endregion



                #region 压缩图片存储尺寸

                if (sEx.ToLower() != ".gif")

                {

                    CompressPhoto(fullPath, 100);

                }

                #endregion







                //生成缩略图片高宽

                if (string.IsNullOrEmpty(SetSmallImgWidth))

                {

                    rm.Message = "上传成功,无缩略图";

                    return rm;

                }





                string[] oWidthArray = SetSmallImgWidth.Split(',');

                string[] oHeightArray = SetSmallImgHeight.Split(',');

                if (oWidthArray.Length != oHeightArray.Length)

                {

                    TryError(rm, 6);

                    return rm;

                }





                for (int i = 0; i < oWidthArray.Length; i++)

                {

                    if (Convert.ToInt32(oWidthArray[i]) <= 0 || Convert.ToInt32(oHeightArray[i]) <= 0)

                        continue;



                    string sImg = SavePath.TrimEnd('\\') + '\\' + NewfileName + "_" + i.ToString() + sEx;



                    //判断图片高宽是否大于生成高宽。否则用原图

                    if (realWidth > Convert.ToInt32(oWidthArray[i]))

                    {

                        if (SetCutImage)

                            CreateSmallPhoto(fullPath, Convert.ToInt32(oWidthArray[i]), Convert.ToInt32(oHeightArray[i]), sImg, "", "");

                        else

                            CreateSmallPhoto(fullPath, Convert.ToInt32(oWidthArray[i]), Convert.ToInt32(oHeightArray[i]), sImg, "", "", CutMode.CutNo);

                    }

                    else

                    {

                        if (SetCutImage)

                            CreateSmallPhoto(fullPath, realWidth, realHeight, sImg, "", "");

                        else

                            CreateSmallPhoto(fullPath, realWidth, realHeight, sImg, "", "", CutMode.CutNo);

                    }

                }



                #region 给大图添加水印

                if (!string.IsNullOrEmpty(SetPicWater))

                    AttachPng(SetPicWater, fullPath);

                else if (!string.IsNullOrEmpty(SetWordWater))

                    AttachText(SetWordWater, fullPath);

                #endregion





            }

            catch (Exception ex)

            {

                TryError(rm, ex.Message);

            }

            return rm;

        }



        #region 验证格式

        /// <summary>

        /// 验证格式

        /// </summary>

        /// <param name="allType">所有格式</param>

        /// <param name="chkType">被检查的格式</param>

        /// <returns>bool</returns>

        public bool CheckValidExt(string allType, string chkType)

        {

            bool flag = false;

            string[] sArray = allType.Split('|');

            foreach (string temp in sArray)

            {

                if (temp.ToLower() == chkType.ToLower())

                {

                    flag = true;

                    break;

                }

            }



            return flag;

        }

        #endregion



        #region 根据需要的图片尺寸，按比例剪裁原始图片

        /// <summary>

        /// 根据需要的图片尺寸，按比例剪裁原始图片

        /// </summary>

        /// <param name="nWidth">缩略图宽度</param>

        /// <param name="nHeight">缩略图高度</param>

        /// <param name="img">原始图片</param>

        /// <returns>剪裁区域尺寸</returns>

        public Size CutRegion(int nWidth, int nHeight, Image img)

        {

            double width = 0.0;

            double height = 0.0;



            double nw = (double)nWidth;

            double nh = (double)nHeight;



            double pw = (double)img.Width;

            double ph = (double)img.Height;



            if (nw / nh > pw / ph)

            {

                width = pw;

                height = pw * nh / nw;

            }

            else if (nw / nh < pw / ph)

            {

                width = ph * nw / nh;

                height = ph;

            }

            else

            {

                width = pw;

                height = ph;

            }



            return new Size(Convert.ToInt32(width), Convert.ToInt32(height));

        }

        #endregion



        #region 等比例缩小图片

        public Size NewSize(int nWidth, int nHeight, Image img)

        {

            double w = 0.0;

            double h = 0.0;

            double sw = Convert.ToDouble(img.Width);

            double sh = Convert.ToDouble(img.Height);

            double mw = Convert.ToDouble(nWidth);

            double mh = Convert.ToDouble(nHeight);



            if (sw < mw && sh < mh)

            {

                w = sw;

                h = sh;

            }

            else if ((sw / sh) > (mw / mh))

            {

                w = nWidth;

                h = (w * sh) / sw;

            }

            else

            {

                h = nHeight;

                w = (h * sw) / sh;

            }



            return new Size(Convert.ToInt32(w), Convert.ToInt32(h));

        }

        #endregion



        #region 生成缩略图



        #region 生成缩略图，不加水印

        /// <summary>

        /// 生成缩略图，不加水印

        /// </summary>

        /// <param name="filename">源文件</param>

        /// <param name="nWidth">缩略图宽度</param>

        /// <param name="nHeight">缩略图高度</param>

        /// <param name="destfile">缩略图保存位置</param>

        public void CreateSmallPhoto(string filename, int nWidth, int nHeight, string destfile)

        {

            Image img = Image.FromFile(filename);

            ImageFormat thisFormat = img.RawFormat;



            Size CutSize = CutRegion(nWidth, nHeight, img);

            Bitmap outBmp = new Bitmap(nWidth, nHeight);

            Graphics g = Graphics.FromImage(outBmp);



            // 设置画布的描绘质量

            g.CompositingQuality = CompositingQuality.HighQuality;

            g.SmoothingMode = SmoothingMode.HighQuality;

            g.InterpolationMode = InterpolationMode.HighQualityBicubic;



            int nStartX = (img.Width - CutSize.Width) / 2;

            int nStartY = (img.Height - CutSize.Height) / 2;



            g.DrawImage(img, new Rectangle(0, 0, nWidth, nHeight),

                nStartX, nStartY, CutSize.Width, CutSize.Height, GraphicsUnit.Pixel);

            g.Dispose();



            //if (thisFormat.Equals(ImageFormat.Gif))

            //{

            //    Response.ContentType = "image/gif";

            //}

            //else

            //{

            //    Response.ContentType = "image/jpeg";

            //}



            // 以下代码为保存图片时，设置压缩质量

            EncoderParameters encoderParams = new EncoderParameters();

            long[] quality = new long[1];

            quality[0] = 100;



            EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);

            encoderParams.Param[0] = encoderParam;



            //获得包含有关内置图像编码解码器的信息的ImageCodecInfo 对象。

            ImageCodecInfo[] arrayICI = ImageCodecInfo.GetImageEncoders();

            ImageCodecInfo jpegICI = null;

            for (int x = 0; x < arrayICI.Length; x++)

            {

                if (arrayICI[x].FormatDescription.Equals("JPEG"))

                {

                    jpegICI = arrayICI[x];//设置JPEG编码

                    break;

                }

            }



            if (jpegICI != null)

            {

                //outBmp.Save(Response.OutputStream, jpegICI, encoderParams);

                outBmp.Save(destfile, jpegICI, encoderParams);

            }

            else

            {

                //outBmp.Save(Response.OutputStream, thisFormat);

                outBmp.Save(destfile, thisFormat);

            }



            img.Dispose();

            outBmp.Dispose();

        }

        #endregion



        #region 生成缩略图，加水印

        public void CreateSmallPhoto(string filename, int nWidth, int nHeight, string destfile, string sy, int nType)

        {

            if (nType == 0)

                CreateSmallPhoto(filename, nWidth, nHeight, destfile, sy, "");

            else

                CreateSmallPhoto(filename, nWidth, nHeight, destfile, "", sy);

        }

        #endregion



        #region 生成缩略图

        /// <summary>

        /// 生成缩略图

        /// </summary>

        /// <param name="filename">源文件</param>

        /// <param name="nWidth">缩略图宽度</param>

        /// <param name="nHeight">缩略图高度</param>

        /// <param name="destfile">缩略图保存位置</param>

        /// <param name="png">图片水印</param>

        /// <param name="text">文本水印</param>

        public void CreateSmallPhoto(string filename, int nWidth, int nHeight, string destfile, string png, string text)

        {

            Image img = Image.FromFile(filename);

            ImageFormat thisFormat = img.RawFormat;



            Size CutSize = CutRegion(nWidth, nHeight, img);

            Bitmap outBmp = new Bitmap(nWidth, nHeight);

            Graphics g = Graphics.FromImage(outBmp);

            g.Clear(Color.White);



            // 设置画布的描绘质量

            g.CompositingQuality = CompositingQuality.HighQuality;

            g.SmoothingMode = SmoothingMode.HighQuality;

            g.InterpolationMode = InterpolationMode.HighQualityBicubic;



            int nStartX = (img.Width - CutSize.Width) / 2;

            int nStartY = (img.Height - CutSize.Height) / 2;



            g.DrawImage(img, new Rectangle(0, 0, nWidth, nHeight),

                nStartX, nStartY, CutSize.Width, CutSize.Height, GraphicsUnit.Pixel);

            g.Dispose();



            // 以下代码为保存图片时，设置压缩质量

            EncoderParameters encoderParams = new EncoderParameters();

            long[] quality = new long[1];

            quality[0] = 100;



            EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);

            encoderParams.Param[0] = encoderParam;



            //获得包含有关内置图像编码解码器的信息的ImageCodecInfo 对象。

            ImageCodecInfo[] arrayICI = ImageCodecInfo.GetImageEncoders();

            ImageCodecInfo jpegICI = null;

            for (int x = 0; x < arrayICI.Length; x++)

            {

                if (arrayICI[x].FormatDescription.Equals("JPEG"))

                {

                    jpegICI = arrayICI[x];//设置JPEG编码

                    break;

                }

            }



            if (jpegICI != null)

            {

                outBmp.Save(destfile, jpegICI, encoderParams);

            }

            else

            {

                outBmp.Save(destfile, thisFormat);

            }



            img.Dispose();

            outBmp.Dispose();



            if (!string.IsNullOrEmpty(png))

                AttachPng(png, destfile);



            if (!string.IsNullOrEmpty(text))

                AttachText(text, destfile);

        }





        public void CreateSmallPhoto(string filename, int nWidth, int nHeight, string destfile, string png, string text, CutMode cMode)

        {

            Image img = Image.FromFile(filename);



            if (nWidth <= 0)

                nWidth = img.Width;

            if (nHeight <= 0)

                nHeight = img.Height;



            int towidth = nWidth;

            int toheight = nHeight;



            switch (cMode)

            {

                case CutMode.CutWH://指定高宽缩放（可能变形）               

                    break;

                case CutMode.CutW://指定宽，高按比例                   

                    toheight = img.Height * nWidth / img.Width;

                    break;

                case CutMode.CutH://指定高，宽按比例

                    towidth = img.Width * nHeight / img.Height;

                    break;

                case CutMode.CutNo: //缩放不剪裁

                    int maxSize = (nWidth >= nHeight ? nWidth : nHeight);

                    if (img.Width >= img.Height)

                    {

                        towidth = maxSize;

                        toheight = img.Height * maxSize / img.Width;

                    }

                    else

                    {

                        toheight = maxSize;

                        towidth = img.Width * maxSize / img.Height;

                    }

                    break;

                default:

                    break;

            }

            nWidth = towidth;

            nHeight = toheight;



            ImageFormat thisFormat = img.RawFormat;



            Size CutSize = new Size(nWidth, nHeight);

            if (cMode != CutMode.CutNo)

                CutSize = CutRegion(nWidth, nHeight, img);



            Bitmap outBmp = new Bitmap(CutSize.Width, CutSize.Height);



            Graphics g = Graphics.FromImage(outBmp);

            g.Clear(Color.White);



            // 设置画布的描绘质量

            g.CompositingQuality = CompositingQuality.HighQuality;

            g.SmoothingMode = SmoothingMode.HighQuality;

            g.InterpolationMode = InterpolationMode.HighQualityBicubic;



            int nStartX = (img.Width - CutSize.Width) / 2;

            int nStartY = (img.Height - CutSize.Height) / 2;



            //int x1 = (outBmp.Width - nWidth) / 2;

            //int y1 = (outBmp.Height - nHeight) / 2;



            if (cMode != CutMode.CutNo)

                g.DrawImage(img, new Rectangle(0, 0, nWidth, nHeight),

                    nStartX, nStartY, CutSize.Width, CutSize.Height, GraphicsUnit.Pixel);

            else

                g.DrawImage(img, new Rectangle(0, 0, nWidth, nHeight),

                0, 0, img.Width, img.Height, GraphicsUnit.Pixel);

            g.Dispose();



            // 以下代码为保存图片时，设置压缩质量

            EncoderParameters encoderParams = new EncoderParameters();

            long[] quality = new long[1];

            quality[0] = 100;



            EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);

            encoderParams.Param[0] = encoderParam;



            //获得包含有关内置图像编码解码器的信息的ImageCodecInfo 对象。

            ImageCodecInfo[] arrayICI = ImageCodecInfo.GetImageEncoders();

            ImageCodecInfo jpegICI = null;

            for (int x = 0; x < arrayICI.Length; x++)

            {

                if (arrayICI[x].FormatDescription.Equals("JPEG"))

                {

                    jpegICI = arrayICI[x];//设置JPEG编码

                    break;

                }

            }



            if (jpegICI != null)

            {

                outBmp.Save(destfile, jpegICI, encoderParams);

            }

            else

            {

                outBmp.Save(destfile, thisFormat);

            }



            img.Dispose();

            outBmp.Dispose();



            if (!string.IsNullOrEmpty(png))

                AttachPng(png, destfile);



            if (!string.IsNullOrEmpty(text))

                AttachText(text, destfile);

        }

        #endregion



        #endregion



        #region 添加文字水印

        public void AttachText(string text, string file)

        {

            if (string.IsNullOrEmpty(text))

                return;



            if (!System.IO.File.Exists(file))

                return;



            System.IO.FileInfo oFile = new System.IO.FileInfo(file);

            string strTempFile = System.IO.Path.Combine(oFile.DirectoryName, Guid.NewGuid().ToString() + oFile.Extension);

            oFile.CopyTo(strTempFile);



            Image img = Image.FromFile(strTempFile);

            ImageFormat thisFormat = img.RawFormat;



            int nHeight = img.Height;

            int nWidth = img.Width;



            Bitmap outBmp = new Bitmap(nWidth, nHeight);

            Graphics g = Graphics.FromImage(outBmp);

            g.Clear(Color.White);



            // 设置画布的描绘质量

            g.CompositingQuality = CompositingQuality.HighQuality;

            g.SmoothingMode = SmoothingMode.HighQuality;

            g.InterpolationMode = InterpolationMode.HighQualityBicubic;



            g.DrawImage(img, new Rectangle(0, 0, nWidth, nHeight),

                0, 0, nWidth, nHeight, GraphicsUnit.Pixel);



            int[] sizes = new int[] { 16, 14, 12, 10, 8, 6, 4 };



            Font crFont = null;

            SizeF crSize = new SizeF();



            //通过循环这个数组，来选用不同的字体大小

            //如果它的大小小于图像的宽度，就选用这个大小的字体

            for (int i = 0; i < 7; i++)

            {

                //设置字体，这里是用arial，黑体

                crFont = new Font("arial", sizes[i], FontStyle.Bold);

                //Measure the Copyright string in this Font

                crSize = g.MeasureString(text, crFont);



                if ((ushort)crSize.Width < (ushort)nWidth)

                    break;

            }



            //因为图片的高度可能不尽相同, 所以定义了

            //从图片底部算起预留了5%的空间

            int yPixlesFromBottom = (int)(nHeight * .08);



            //现在使用版权信息字符串的高度来确定要绘制的图像的字符串的y坐标



            float yPosFromBottom = ((nHeight - yPixlesFromBottom) - (crSize.Height / 2));



            //计算x坐标

            float xCenterOfImg = (nWidth / 2);



            //把文本布局设置为居中

            StringFormat StrFormat = new StringFormat();

            StrFormat.Alignment = StringAlignment.Center;



            //通过Brush来设置黑色半透明

            SolidBrush semiTransBrush2 = new SolidBrush(Color.FromArgb(153, 0, 0, 0));



            //绘制版权字符串

            g.DrawString(text,                 //版权字符串文本

                crFont,                                   //字体

                semiTransBrush2,                           //Brush

                new PointF(xCenterOfImg + 1, yPosFromBottom + 1),  //位置

                StrFormat);



            //设置成白色半透明

            SolidBrush semiTransBrush = new SolidBrush(Color.FromArgb(153, 255, 255, 255));



            //第二次绘制版权字符串来创建阴影效果

            //记住移动文本的位置1像素

            g.DrawString(text,                 //版权文本

                crFont,                                   //字体

                semiTransBrush,                           //Brush

                new PointF(xCenterOfImg, yPosFromBottom),  //位置

                StrFormat);



            g.Dispose();



            // 以下代码为保存图片时，设置压缩质量

            EncoderParameters encoderParams = new EncoderParameters();

            long[] quality = new long[1];

            quality[0] = 100;



            EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);

            encoderParams.Param[0] = encoderParam;



            //获得包含有关内置图像编码解码器的信息的ImageCodecInfo 对象。

            ImageCodecInfo[] arrayICI = ImageCodecInfo.GetImageEncoders();

            ImageCodecInfo jpegICI = null;

            for (int x = 0; x < arrayICI.Length; x++)

            {

                if (arrayICI[x].FormatDescription.Equals("JPEG"))

                {

                    jpegICI = arrayICI[x];//设置JPEG编码

                    break;

                }

            }



            if (jpegICI != null)

            {

                outBmp.Save(file, jpegICI, encoderParams);

            }

            else

            {

                outBmp.Save(file, thisFormat);

            }



            img.Dispose();

            outBmp.Dispose();



            System.IO.File.Delete(strTempFile);

        }

        #endregion



        #region 添加图片水印

        ///<summary>

        /// 添加图片水印

        /// </summary>

        /// <param name="png">水印图片</param>

        /// <param name="file">原文件</param>

        /// <param name="position">水印图片的位置 0居中、1左上角、2右上角、3左下角、4右下角</param>

        public void AttachPng(string png, string file)

        {

            if (string.IsNullOrEmpty(png))

                return;



            if (!System.IO.File.Exists(png))

                return;



            if (!System.IO.File.Exists(file))

                return;



            System.IO.FileInfo oFile = new System.IO.FileInfo(file);

            string strTempFile = System.IO.Path.Combine(oFile.DirectoryName, Guid.NewGuid().ToString() + oFile.Extension);

            oFile.CopyTo(strTempFile);



            Image img = Image.FromFile(strTempFile);

            ImageFormat thisFormat = img.RawFormat;

            int nHeight = img.Height;

            int nWidth = img.Width;



            Bitmap outBmp = new Bitmap(nWidth, nHeight);

            Graphics g = Graphics.FromImage(outBmp);



            // 设置画布的描绘质量

            g.CompositingQuality = CompositingQuality.HighQuality;

            g.SmoothingMode = SmoothingMode.HighQuality;

            g.InterpolationMode = InterpolationMode.HighQualityBicubic;



            g.DrawImage(img, new Rectangle(0, 0, nWidth, nHeight),

                0, 0, nWidth, nHeight, GraphicsUnit.Pixel);



            img.Dispose();



            img = Image.FromFile(png);



            //Bitmap bmpPng = new Bitmap(img);



            //ImageAttributes imageAttr = new ImageAttributes();

            //Color bg = Color.Green;

            //imageAttr.SetColorKey(bg, bg);



            Size pngSize = NewSize(nWidth, nHeight, img);

            int nx = 0;

            int ny = 0;

            int padding = 10;

            if (SetPositionWater == 0)

            {

                nx = (nWidth - pngSize.Width) / 2;

                ny = (nHeight - pngSize.Height) / 2;

            }

            else if (SetPositionWater == 1)

            {

                nx = padding;

                ny = padding;

            }

            else if (SetPositionWater == 2)

            {

                nx = (nWidth - pngSize.Width) - padding;

                ny = padding;

            }

            else if (SetPositionWater == 3)

            {

                nx = padding;

                ny = (nHeight - pngSize.Height) - padding;

            }

            else

            {

                nx = (nWidth - pngSize.Width) - padding;

                ny = (nHeight - pngSize.Height) - padding;

            }

            g.DrawImage(img, new Rectangle(nx, ny, pngSize.Width, pngSize.Height),

                0, 0, img.Width, img.Height, GraphicsUnit.Pixel);



            g.Dispose();



            // 以下代码为保存图片时，设置压缩质量

            EncoderParameters encoderParams = new EncoderParameters();

            long[] quality = new long[1];

            quality[0] = 100;



            EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);

            encoderParams.Param[0] = encoderParam;



            //获得包含有关内置图像编码解码器的信息的ImageCodecInfo 对象。

            ImageCodecInfo[] arrayICI = ImageCodecInfo.GetImageEncoders();

            ImageCodecInfo jpegICI = null;

            for (int x = 0; x < arrayICI.Length; x++)

            {

                if (arrayICI[x].FormatDescription.Equals("JPEG"))

                {

                    jpegICI = arrayICI[x];//设置JPEG编码

                    break;

                }

            }



            if (jpegICI != null)

            {

                outBmp.Save(file, jpegICI, encoderParams);

            }

            else

            {

                outBmp.Save(file, thisFormat);

            }



            img.Dispose();

            outBmp.Dispose();



            System.IO.File.Delete(strTempFile);

        }

        #endregion



        #region 得到指定mimeType的ImageCodecInfo

        /// <summary>

        /// 保存JPG时用

        /// </summary>

        /// <param name="mimeType"> </param>

        /// <returns>得到指定mimeType的ImageCodecInfo </returns>

        private ImageCodecInfo GetCodecInfo(string mimeType)

        {

            ImageCodecInfo[] CodecInfo = ImageCodecInfo.GetImageEncoders();

            foreach (ImageCodecInfo ici in CodecInfo)

            {

                if (ici.MimeType == mimeType) return ici;

            }

            return null;

        }

        #endregion



        #region 保存为JPEG格式，支持压缩质量选项

        /// <summary>

        /// 保存为JPEG格式，支持压缩质量选项

        /// </summary>

        /// <param name="SourceFile"></param>

        /// <param name="FileName"></param>

        /// <param name="Qty"></param>

        /// <returns></returns>

        public bool KiSaveAsJPEG(string SourceFile, string FileName, int Qty)

        {

            Bitmap bmp = new Bitmap(SourceFile);



            try

            {

                EncoderParameter p;

                EncoderParameters ps;



                ps = new EncoderParameters(1);



                p = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, Qty);

                ps.Param[0] = p;



                bmp.Save(FileName, GetCodecInfo("image/jpeg"), ps);



                bmp.Dispose();



                return true;

            }

            catch

            {

                bmp.Dispose();

                return false;

            }



        }

        #endregion



        #region 将图片压缩到指定大小

        /// <summary>

        /// 将图片压缩到指定大小

        /// </summary>

        /// <param name="FileName">待压缩图片</param>

        /// <param name="size">期望压缩后的尺寸</param>

        public void CompressPhoto(string FileName, int size)

        {

            if (!System.IO.File.Exists(FileName))

                return;



            int nCount = 0;

            System.IO.FileInfo oFile = new System.IO.FileInfo(FileName);

            long nLen = oFile.Length;

            while (nLen > size * 1024 && nCount < 10)

            {

                string dir = oFile.Directory.FullName;

                string TempFile = System.IO.Path.Combine(dir, Guid.NewGuid().ToString() + "." + oFile.Extension);

                oFile.CopyTo(TempFile, true);



                KiSaveAsJPEG(TempFile, FileName, 70);



                try

                {

                    System.IO.File.Delete(TempFile);

                }

                catch { }



                nCount++;



                oFile = new System.IO.FileInfo(FileName);

                nLen = oFile.Length;

            }

        }

        #endregion



        #endregion





        #region common method



        /// <summary>

        /// 图片上传错误编码

        /// </summary>

        /// <param name="code"></param>

        /// <returns></returns>

        private string GetCodeMessage(int code)

        {

            var dic = new Dictionary<int, string>(){

        {0,"系统配置错误"},

        {1,"上传图片成功"},

        {2,string.Format( "对不起，上传格式错误！请上传{0}格式图片",SetAllowFormat)},

        {3,string.Format("超过文件上传大小,不得超过{0}M",SetAllowSize)},

        {4,"未上传文件"},

        {5,""},

        {6,"缩略图长度和宽度配置错误"},

        {7,"检测图片宽度限制"}

         };

            return dic[code];

        }

        private void TryError(ResponseMessage rm, int code)

        {

            rm.IsError = true;

            rm.Message = GetCodeMessage(code);

        }

        private void TryError(ResponseMessage rm, string message)

        {

            rm.IsError = true;

            rm.Message = message;

        }

        #endregion



        #region models

        public enum CutMode

        {

            /// <summary>

            /// 根据高宽剪切

            /// </summary>

            CutWH = 1,

            /// <summary>

            /// 根据宽剪切

            /// </summary>

            CutW = 2,

            /// <summary>

            /// 根据高剪切

            /// </summary>

            CutH = 3,

            /// <summary>

            /// 缩放不剪裁

            /// </summary>

            CutNo = 4

        }

        public class ResponseMessage

        {

            /// <summary>

            /// 是否遇到错误

            /// </summary>

            public bool IsError { get; set; }

            /// <summary>

            /// web路径

            /// </summary>

            public string WebPath { get; set; }

            /// <summary>

            /// 文件物理路径

            /// </summary>

            public string filePath { get; set; }

            /// <summary>

            /// 反回消息

            /// </summary>

            public string Message { get; set; }

            /// <summary>

            /// 文件大小

            /// </summary>

            public double Size { get; set; }

            /// <summary>

            /// 图片名

            /// </summary>

            public string FileName { get; set; }

            /// <summary>

            /// 图片目录

            /// </summary>

            public string Directory

            {

                get

                {

                    if (WebPath == null) return null;

                    return WebPath.Replace(FileName, "");

                }

            }

            /// <summary>

            /// 缩略图路径

            /// </summary>

            public string SmallPath(int index)

            {

                return string.Format("{0}{1}_{2}{3}", Directory, Path.GetFileNameWithoutExtension(FileName), index, Path.GetExtension(FileName));

            }

        }

        #endregion

    }



}