分享一个项目中在用的图片处理工具类(图片缩放，旋转，画布格式，字节,image,bitmap转换等)

using System;

using System.Collections.Generic;

using System.IO;

using System.Text;

using System.Drawing;

using System.Drawing.Drawing2D;

using System.Threading;

namespace ConfigLab.Comp.Img.ImgUtils

{

    /// <summary>

    /// 功能简介：图片转换类

    /// 创建时间：2016-9-10

    /// 创建人：pcw

    /// 博客：http://www.cnblogs.com/taohuadaozhu

    /// </summary>

    public class ImgConvert

    {

        /// <summary>

        /// 字节数组转换为bitmap

        /// </summary>

        /// <param name="buffer"></param>

        /// <returns></returns>

        public static Bitmap BytesToBitmap(byte[] buffer)

        {

            Bitmap bitmapResult = null;

            if (buffer != null && buffer.Length > 0)

            {

                using (MemoryStream ms = new MemoryStream(buffer))

                {

                    try

                    {

                        bitmapResult = new Bitmap(ms);

                        return bitmapResult;

                    }

                    catch (Exception error)

                    {

                        return bitmapResult;

                    }

                    finally

                    {

                        ms.Close();

                        ms.Dispose();

                    }

                }

            }

            return null;

        }

        /// <summary>

        /// 字节数组转换为Image对象

        /// </summary>

        /// <param name="buffer"></param>

        /// <returns></returns>

        public static Image BytesToImage(byte[] buffer)

        {

            if (buffer != null && buffer.Length > 0)

            {

                using (MemoryStream ms = new MemoryStream(buffer))

                {

                    Image image = null;

                    try

                    {

                        image = Image.FromStream(ms);

                        return image;

                    }

                    catch (Exception error)

                    {

                        return image;

                    }

                    finally

                    {

                        ms.Close();

                        ms.Dispose();

                    }

                }

            }

            return null;

        }

        /// <summary>

        /// 按照一定的比率进行放大或缩小

        /// </summary>

        /// <param name="Percent">缩略图的宽度百分比 如：需要百分之80，就填0.8</param>

        /// <param name="rotateFlipType">

        ///顺时针旋转90度     RotateFlipType.Rotate90FlipNone

        ///逆时针旋转90度     RotateFlipType.Rotate270FlipNone

        ///水平翻转           RotateFlipType.Rotate180FlipY

        ///垂直翻转          RotateFlipType.Rotate180FlipX

        ///保持原样           RotateFlipType.RotateNoneFlipNone

        /// </param>

        /// <param name="IsTransparent">背景是否透明</param>

        /// <returns>Bitmap对象</returns>

        public static Bitmap GetImage_Graphics(Image ResourceImage, double Percent, RotateFlipType rotateFlipType, bool IsTransparent)

        {

            Bitmap ResultBmp = null;

            try

            {

                if (ResourceImage != null)

                {

                    ResourceImage.RotateFlip(rotateFlipType);

                    int _newWidth = (int)Math.Round(ResourceImage.Width * Percent);

                    int _newHeight = (int)Math.Round(ResourceImage.Height * Percent);

                    ResultBmp = new System.Drawing.Bitmap(_newWidth, _newHeight, System.Drawing.Imaging.PixelFormat.Format32bppArgb);//创建图片对象

                    Graphics g = null;

                    try

                    {

                        g = Graphics.FromImage(ResultBmp);//创建画板并加载空白图像

                        if (g != null)

                        {

                            g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.NearestNeighbor; //System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;//设置保真模式为高度保真

                            g.DrawImage(ResourceImage, new Rectangle(0, 0, _newWidth, _newHeight), 0, 0, ResourceImage.Width, ResourceImage.Height, GraphicsUnit.Pixel);//开始画图

                            if (IsTransparent)

                            {

                                ResultBmp.MakeTransparent(System.Drawing.Color.Transparent);

                            }

                        }

                    }

                    catch (Exception errr)

                    {

                        ConfigLab.Utils.SaveErrorLog(string.Format("GetImage_Graphics(1)，异常={0}", errr.Message));

                        Thread.Sleep(100);

                    }

                    finally

                    {

                        if (g != null)

                        {

                            g.Dispose();

                        }

                    }

                }

            }

            catch (Exception ex)

            {

                ConfigLab.Utils.SaveErrorLog(string.Format("GetImage_Graphics(2)，异常={0}", ex.Message));

                Thread.Sleep(100);

                return null;

            }

            finally

            {

                if (ResourceImage != null)

                {

                    ResourceImage.Dispose();

                }

            }

            return ResultBmp;

        }

        /// <summary>

        /// 图片等比缩放

        /// </summary>

        /// <param name="sImgFilePath"></param>

        /// <param name="Percent"></param>

        /// <returns></returns>

        public static bool ChangeImgSize(string sImgFilePath, double Percent,string sNewImgFilePath)

        {

            Image img = null;

            Bitmap bp = null;

            bool bSuccess = false;

            try

            {

                if (File.Exists(sImgFilePath) == false)

                {

                    Utils.SaveErrorLog(string.Format("找不到待压缩的原文件{0}", sImgFilePath));

                    return false;

                }

                img = Image.FromFile(sImgFilePath);

                if (img != null)

                {

                    bp = GetImage_Graphics(img, Percent, RotateFlipType.RotateNoneFlipNone, true);

                    if (bp != null)

                    {

                        string sDirectory = FilePathUtils.getDirectory(sNewImgFilePath);

                        if (sDirectory.EndsWith("\\") == false)

                        {

                            sDirectory = string.Format("{0}\\", sDirectory);

                        }

                        bp.Save(sNewImgFilePath);

                        bSuccess=true;

                    }

                }

            }

            catch(Exception ex)

            {

                Utils.SaveErrorLog(string.Format("ChangeImgSize处理{0}的图片且保存到{1}的任务执行失败",sImgFilePath,sNewImgFilePath), ex);

            }

            finally

            {

                if (img != null)

                {

                    img.Dispose();

                }

                if (bp != null)

                {

                    bp.Dispose();

                }

            }

            return bSuccess;

        }

        /// <summary>

        /// Resize图片

        /// </summary>

        /// <param name="bmp">原始Bitmap</param>

        /// <param name="newW">新的宽度</param>

        /// <param name="newH">新的高度</param>

        /// <returns>处理以后的Bitmap</returns>

        public static Bitmap ResizeBmp(Bitmap bmp, int newW, int newH)

        {

            try

            {

                Bitmap b = new Bitmap(newW, newH);

                Graphics g = Graphics.FromImage(b);

                g.SmoothingMode = SmoothingMode.HighSpeed;

                g.CompositingQuality = CompositingQuality.HighSpeed;

                g.InterpolationMode = InterpolationMode.Low;

                g.DrawImage(bmp, new Rectangle(0, 0, newW, newH), new Rectangle(0, 0, bmp.Width, bmp.Height), GraphicsUnit.Pixel);

                g.Dispose();

                return b;

            }

            catch

            {

                return null;

            }

        }

        /// 将图片Image转换成Byte[]

        /// </summary>

        /// <param name="Image">image对象</param>

        /// <param name="imageFormat">后缀名</param>

        /// <returns></returns>

        public static byte[] ImageToBytes(Image Image, System.Drawing.Imaging.ImageFormat imageFormat)

        {

            if (Image == null) { return null; }

            byte[] data = null;

            using (MemoryStream ms = new MemoryStream())

            {

                using (Bitmap Bitmap = new Bitmap(Image))

                {

                    Bitmap.Save(ms, imageFormat);

                    ms.Position = 0;

                    data = new byte[ms.Length];

                    ms.Read(data, 0, Convert.ToInt32(ms.Length));

                    ms.Flush();

                }

            }

            return data;

        }

        /// <summary>

        /// 通过FileStream 来打开文件，这样就可以实现不锁定Image文件，到时可以让多用户同时访问Image文件

        /// </summary>

        /// <param name="path"></param>

        /// <returns></returns>

        public static Bitmap ReadImageFile(string path)

        {

            if (string.IsNullOrEmpty(path))

                return null;

            if (File.Exists(path) == false)

                return null;

            int filelength = 0;

            Bitmap bit = null;

            Byte[] image = null;

            try

            {

                using (FileStream fs = File.OpenRead(path))//OpenRead

                {

                    filelength = (int)fs.Length; //获得文件长度

                    image = new Byte[filelength]; //建立一个字节数组

                    fs.Read(image, 0, filelength); //按字节流读取

                    System.Drawing.Image result = System.Drawing.Image.FromStream(fs);

                    bit = new Bitmap(result);

                    if (fs != null)

                    {

                        fs.Close();

                        fs.Dispose();

                    }

                }

            }

            catch (Exception err)

            {

                ConfigLab.Utils.SaveErrorLog(string.Format("读取图片【{0}】失败,调试信息={1}", path, err.Message + err.StackTrace));

            }

            finally

            {

                if (image != null)

                {

                    image = null;

                }

            }

            return bit;

        }

    }

}

分享一个项目中在用的图片处理工具类(图片缩放，旋转，画布格式，字节,image,bitmap转换等)的相关教程结束。