FastDfs在NET下的使用

FastDfs是一个开源的轻量级分布式文件系统，其原理可以查看http://blog.chinaunix.net/uid-20196318-id-4058561.html，然后部署安装部分可参考http://blog.csdn.net/poechant/article/details/7209313，这里只是简单的说明下在C#中如何使用FastDfs。

首先是通过Nuget下载dll，具体地址为https://www.nuget.org/packages/FastDFS/

然后可以通过程序来设置相关Tracker服务器地址及群组信息，也可以通过配置文件来配置

通过代码方式的话是如下方式

            new FastDfsConfig
            {
                //FastDfsServer =...,
                //GroupName =...
            };

而通过配置文件方式的话，需要在配置文件的configSections节点中添加如下配置

其中fastdfs为默认节点名，当然name也可以指定为其它值，然后实际配置如下

然后在代码中通过下列代码来初始化

            Config = FastDfsManager.GetConfigSection();
            ConnectionManager.InitializeForConfigSection(Config);

FastDfs相关的操作代码主要集中在FastDFSClient类中，然后实际项目中我们只是用到了UploadFile，所以也就只是简单地做了个封装

    using FastDFS.Client;
    using FastDFS.Client.Config;
    using System.IO;

    public static class FastDfsHelper
    {
        /// 

        /// Dfs文件
        /// 
        public class FastDfsFile
        {
            /// 

            /// Dfs群组名
            /// 
            public string GroupName { get; private set; }
            /// 

            /// Dfs文件路径（包含文件名）
            /// 
            public string FileName { get; private set; }
            public FastDfsFile(string groupName, string fileName)
            {
                if (string.IsNullOrWhiteSpace(groupName))
                {
                    throw new ArgumentNullException("groupName can not be null.");
                }
                if (string.IsNullOrWhiteSpace(fileName))
                {
                    throw new ArgumentNullException("fileName can not be null.");
                }
                this.GroupName = groupName;
                this.FileName = fileName;
            }
            /// 

            /// 获取文件在服务器上访问的路径（不包含域名部分）
            /// 
            /// 
            public override string ToString()
            {
                return string.Format("{0}/{1}", this.GroupName, this.FileName);
            }
        }
        static readonly FastDfsConfig Config;
        static FastDfsHelper()
        {
            Config = FastDfsManager.GetConfigSection();
            ConnectionManager.InitializeForConfigSection(Config);
        }
        /// 

        /// 上传文件
        /// 
        /// 文件数组
        /// 
        /// 
        public static FastDfsFile Upload(byte[] contentByte, string fileExt)
        {
            var node = FastDFSClient.GetStorageNode(Config.GroupName);
            return new FastDfsFile(Config.GroupName, FastDFSClient.UploadFile(node, contentByte, fileExt.Trim('.')));
        }
        /// 

        /// 上传文件
        /// 
        /// 文件流
        /// 
        /// 
        public static FastDfsFile Upload(Stream stream, string fileExt)
        {
            using (stream)
            {
                byte[] contentByte = new byte[stream.Length];
                stream.Read(contentByte, 0, contentByte.Length);
                return Upload(contentByte, fileExt);
            }
        }
        /// 

        /// 将数据流读取成byte数组，并在读取完成后将流当前位置设置为0
        /// 
        /// 
        /// 
        public static byte[] StreamToBytes(Stream stream)
        {
            byte[] bytes = new byte[stream.Length];
            stream.Read(bytes, 0, bytes.Length);
            // 设置当前流的位置为流的开始
            stream.Seek(0, SeekOrigin.Begin);
            return bytes;
        }
        /// 

        /// 移除文件
        /// 
        /// 
        /// 
        public static void Remove(string groupName, string fileName)
        {
            FastDFSClient.RemoveFile(groupName, fileName);
        }
    }

然后因为我们主要是上传图片，所以这里还从网上找了段压缩的代码，然后简单的调整了下

    using System.Drawing;
    using System.Drawing.Drawing2D;
    using System.Drawing.Imaging;
    using System.IO;

    public static class ImageHelper
    {
        /// 

        /// JPG编码解码器信息，为null表示未安装
        /// 
        public static readonly ImageCodecInfo JPEGICIinfo;
        static ImageHelper()
        {
            JPEGICIinfo = GetJPEGICIinfo();
        }
        /// 

        /// 图片压缩并获得压缩后的数据流，如果出现异常则返回null，注意使用完之后释放
        /// 
        /// 原始图片内容
        /// 压缩后的最大高度
        /// 压缩后的最大宽度
        /// 压缩质量 1-100
        /// 
        public static Stream GetPicThumbnail(byte[] imgByte, int dHeight, int dWidth, int flag)
        {
            using (var sStream = new MemoryStream(imgByte))
            {
                Image iSource = Image.FromStream(sStream);
                ImageFormat tFormat = iSource.RawFormat;
                //按比例缩放
                var zSize = GetZoomSize(new Size(iSource.Width, iSource.Height), dWidth, dHeight);
                Bitmap ob = new Bitmap(zSize.Width, zSize.Height);
                using (Graphics g = Graphics.FromImage(ob))
                {
                    g.CompositingQuality = CompositingQuality.HighQuality;
                    g.SmoothingMode = SmoothingMode.HighQuality;
                    g.InterpolationMode = InterpolationMode.HighQualityBicubic;
                    g.DrawImage(iSource, new Rectangle(0, 0, zSize.Width, zSize.Height), 0, 0, iSource.Width, iSource.Height, GraphicsUnit.Pixel);
                }
                MemoryStream rStream = new MemoryStream();
                try
                {
                    if (JPEGICIinfo != null)
                    {
                        ob.Save(rStream, JPEGICIinfo, GetEncoderParameters(flag));
                    }
                    else
                    {
                        ob.Save(rStream, tFormat);
                    }
                    rStream.Position = 0;
                }
                catch
                {
                    rStream.Dispose();
                    rStream = null;
                }
                finally
                {
                    iSource.Dispose();
                    ob.Dispose();
                }
                return rStream;
            }
        }
        private static Size GetZoomSize(Size sSize, int dWidth, int dHeight)
        {
            int sW = sSize.Width, sH = sSize.Height;
            //按比例缩放
            if (sSize.Width > dHeight || sSize.Width > dWidth) //将**改成c#中的或者操作符号
            {
                if ((sSize.Width * dHeight) > (sSize.Height * dWidth))
                {
                    sW = dWidth;
                    sH = (dWidth * sSize.Height) / sSize.Width;
                }
                else
                {
                    sH = dHeight;
                    sW = (sSize.Width * dHeight) / sSize.Height;
                }
            }
            return new Size(sW, sH);
        }
        private static ImageCodecInfo GetJPEGICIinfo()
        {
            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;
        }
        private static EncoderParameters GetEncoderParameters(int flag)
        {
            //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;
            return ep;
        }
    }

简单的使用代码如下

            string localPath = @"E:\demoPic\03.jpg";
            string newPath1 = @"E:\demoPic\NN03.jpg";
            var imgByte = File.ReadAllBytes(localPath);
            //图片压缩
            var stream = ImageHelper.GetPicThumbnail(imgByte, 500, 500, 70);
            if (stream != null)
            {
                using (stream)
                {
                    byte[] bytes = FastDfsHelper.StreamToBytes(stream);
                    //文件上传
                    var file = FastDfsHelper.Upload(stream, Path.GetExtension(localPath).Trim('.'));
                    Console.WriteLine(file);//file.ToString()结果就为排除fastDfs访问域名后完整的图片访问路径
                    File.WriteAllBytes(newPath1, bytes);//本地存储以便与上传到Dfs的文件进行比较
                }
            }