WCF筆記(5)流模式與文件傳輸

開啓流模式，主要是設置一個叫TransferMode的屬性，所以，你看看哪些Binding的派生類有這個屬性就可以了。

TransferMode其實是一個舉枚，看看它的幾個有效值：

• Buffered：緩衝模式，說白了就是在內存中緩衝，一次調用就把整個消息讀/寫完，也就是我們最常用的方式，就是普通的操作協定的調用方式；
• StreamedRequest：只是在請求的時候使用流，說簡單一點就是在傳入方法的參數使用流，如 int MyMethod(System.IO.Stream stream);
• StreamedResponse：就是操作協定方法返回一個流，如 Stream MyMethod(string file_name);

一般而言，如果使用流作爲傳入參數，最好不要使用多個參數。

示例代碼

1、服務端

using System;
using System.ServiceModel;
using System.ServiceModel.Description;
using System.IO;

namespace Server
{
    class Program
    {
        //設置服務並啓動
        static void Main()
        {
            //服務基地址
            Uri baseUri = new Uri("http://localhost:3000/Service");
            //聲明服務器主機
            using (ServiceHost host = new ServiceHost(typeof(MyService), baseUri))
            {
                //添加綁定和終結點
                BasicHttpBinding binding = new BasicHttpBinding();
                //啓用流模式
                binding.TransferMode = TransferMode.StreamedRequest;
                binding.MaxBufferSize = 1024;
                //接收消息的最大範圍500M
                binding.MaxReceivedMessageSize = 500*1024*1024;
                host.AddServiceEndpoint(typeof(IService), binding, "test");
                //添加服務描述
                host.Description.Behaviors.Add(new ServiceMetadataBehavior { HttpGetEnabled = true });
                //啓動服務
                try
                {
                    host.Open();
                    Console.WriteLine("服務已啓動");
                }
                catch (Exception ex)
                {
                    Console.WriteLine(ex.Message);
                }
                Console.ReadKey();
                //關閉服務
                host.Close();
            }
        }
    }

    /// <summary>
    /// 定義服務協定
    /// </summary>
    [ServiceContract]
    public interface IService
    {
        [OperationContract]
        ResponseMessage UpLoadFile(StreamFile  stream);
    }

    /// <summary>
    /// 實現服務協定
    /// </summary>
    public class MyService : IService
    {
        public ResponseMessage UpLoadFile(StreamFile stream)
        {
            ResponseMessage result=new ResponseMessage();
            if (stream == null || stream.FileStream == null || string.IsNullOrEmpty(stream.FileName))
            {
                result.IsSuccessed = false;
                result.ErrorMessage = "流文件爲空!";
                return result;
            }
            try
            {
                using (FileStream fs = new FileStream(stream.FileName, FileMode.OpenOrCreate, FileAccess.Write))
                {
                    // 我們不用對兩個流對象進行讀寫，只要複製流就OK
                    stream.FileStream.CopyTo(fs);
                    fs.Flush();
                    result.IsSuccessed = true;
                    Console.WriteLine("{0}接收到客戶端發送的流，已保存到{1}", DateTime.Now.ToLongTimeString(), stream.FileName);
                }
            }
            catch (Exception ex)
            {
                result.ErrorMessage = ex.Message;
                result.IsSuccessed = false;
            }
            return result;
        }
    }

    [MessageContract]
    public class StreamFile
    {
        /// <summary>
        /// 流文件名稱
        /// </summary>
        [MessageHeader]
        public string FileName { get; set; }

        /// <summary>
        /// 流文件
        /// </summary>
        [MessageBodyMember]
        public Stream FileStream { get; set; }
    }

    [MessageContract]
    public class ResponseMessage
    {
        /// <summary>
        /// 是否成功
        /// </summary>
        [MessageBodyMember]
        public bool IsSuccessed { get; set; }

        /// <summary>
        /// 錯誤信息
        /// </summary>
        [MessageBodyMember]
        public string ErrorMessage { get; set; }
    }
}
 

2、客戶端

using System;
using System.Windows.Forms;
using System.IO;

namespace Client
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void btnOpen_Click(object sender, EventArgs e)
        {
            OpenFileDialog ofd = new OpenFileDialog();
            ofd.Filter = "所有文件|*.*";
            if (ofd.ShowDialog() == DialogResult.OK)
            {
                txtFileName.Text = ofd.FileName;
            }
        }

        private async  void btnUpLoad_Click(object sender, EventArgs e)
        {
            if (txtFileName.Text.Trim() == "")
            {
                MessageBox.Show("請選擇上傳的文件！");
                btnOpen.Focus();
                return;
            }
            btnUpLoad.Enabled = false;
            FileStream fs = new FileStream(txtFileName.Text.Trim(), FileMode.Open, FileAccess.Read);
            WS.ServiceClient sc = new WS.ServiceClient();
            WS.StreamFile sf = new WS.StreamFile(Path.GetFileName(txtFileName.Text.Trim()), fs);
            var response = await sc.UpLoadFileAsync(sf);
            if (response.IsSuccessed)
            {
                MessageBox.Show("上傳成功");
            }
            else
            {
                MessageBox.Show(string.Format("上傳失敗！錯誤信息：{0}", response.ErrorMessage));
            }
            btnUpLoad.Enabled = true;
        }
    }
}