使用 WCF rest 下载文件

本文关键字：文件 下载 rest WCF 使用 | 更新日期: 2023-09-27 18:35:30

我正在使用 .net 4.0 并尝试使用 rest wcf 服务上传文件，并使用称为 upload 的方法上传文件，并使用称为下载的方法使用相同的 rest 服务下载该文件。有一个控制台应用程序将流数据发送到 wcf 服务，并且相同的控制台应用从该服务下载。控制台应用程序使用 WebChannelFactory 来连接和使用服务。

下面是来自控制台应用的代码 

            StreamReader fileContent = new StreamReader(fileToUpload, false);
            webChannelServiceImplementation.Upload(fileContent.BaseStream );

这是 wcf 服务代码

public void Upload(Stream fileStream)
{
        long filebuffer  = 0;
        while (fileStream.ReadByte()>0)
        {
            filebuffer++;
        }
        byte[] buffer = new byte[filebuffer];
        using (MemoryStream memoryStream = new MemoryStream())
        {
            int read;
            while ((read = fileStream.Read(buffer, 0, buffer.Length)) > 0)
            {
                memoryStream.Write(buffer, 0, read);
            }
            File.WriteAllBytes(path, buffer);
        }
}
现在，在此步骤中，当我检查文件时，

我注意到它的大小（以千字节为单位）与从控制台应用程序发送的原始文件相同，但是当我打开该文件时，它没有任何内容。该文件可以是任何文件类型，无论是 excel 还是 word 文档，它仍然作为空文件出现在服务器上。所有数据都去哪儿了？

我之所以做fileStream.ReadByte()>0是因为我在某处读到，通过网络传输时，找不到缓冲区长度（这就是为什么我在尝试在服务upload方法中获取流的长度时出现异常的原因）。这就是为什么我不使用byte[] buffer = new byte[32768];，如许多在线示例所示，其中字节数组是固定的。

从服务下载时，我在 wcf 服务端使用此代码

    public Stream Download()
    {
        return new MemoryStream(File.ReadAllBytes("filename"));
    }

在控制台应用程序方面，我有 

        Stream fileStream = webChannelServiceImplementation.Download();
        //find size of buffer
        long size= 0;
        while (fileStream .ReadByte() > 0)
        {
            size++;
        }
        byte[] buffer = new byte[size];
        using (Stream memoryStream = new MemoryStream())
        {
            int read;
            while ((read = fileContents.Read(buffer, 0, buffer.Length)) > 0)
            {
                memoryStream.Write(buffer, 0, read);
            }
            File.WriteAllBytes("filename.doc", buffer);
        }

现在这个下载的文件也是空白的，因为它下载了我之前使用上面的上传代码上传的文件，即使上传的文件大小为 200 KB，它的大小也只有 16 KB。

我的代码有什么问题？任何帮助表示赞赏。

使用 WCF rest 下载文件

你可以使这更简单：

public void Upload(Stream fileStream)
{
    using (var output = File.Open(path, FileMode.Create))
        fileStream.CopyTo(output);
}

现有代码的问题在于，您调用ReadByte并读取整个输入流，然后尝试再次读取它（但现在它在末尾）。 这意味着您的第二次读取将全部失败（循环中的read变量将为 0，并立即爆发），因为流现在处于其末尾。

在这里，我创建了一个 WCF REST 服务。Service.svc.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.ServiceModel.Web;
using System.Text;
namespace UploadSvc
{
    // NOTE: You can use the "Rename" command on the "Refactor" menu to change the class name "Service1" in code, svc and config file together.
[ServiceBehavior(ConcurrencyMode = ConcurrencyMode.Multiple,
                 InstanceContextMode = InstanceContextMode.PerCall,
                 IgnoreExtensionDataObject = true,
                 IncludeExceptionDetailInFaults = true)]    
      public class UploadService : IUploadService
    {
        public UploadedFile Upload(Stream uploading)
        {
            var upload = new UploadedFile
            {
                FilePath = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString())
            };
            int length = 0;
            using (var writer = new FileStream(upload.FilePath, FileMode.Create))
            {
                int readCount;
                var buffer = new byte[8192];
                while ((readCount = uploading.Read(buffer, 0, buffer.Length)) != 0)
                {
                    writer.Write(buffer, 0, readCount);
                    length += readCount;
                }
            }
            upload.FileLength = length;
            return upload;
        }
        public UploadedFile Upload(UploadedFile uploading, string fileName)
        {
            uploading.FileName = fileName;
            return uploading;
        }
    }
}

网络.config

<?xml version="1.0"?>
<configuration>
  <system.web>
    <compilation debug="true" targetFramework="4.0" />
    <httpRuntime executionTimeout="100000" maxRequestLength="20000000"/>
  </system.web>
  <system.serviceModel>
    <bindings>
      <webHttpBinding>
        <binding maxBufferSize="2147483647"
                 maxBufferPoolSize="2147483647"
                 maxReceivedMessageSize="2147483647"
                 transferMode="Streamed"
                 sendTimeout="00:05:00" closeTimeout="00:05:00" receiveTimeout="00:05:00">
          <readerQuotas  maxDepth="2147483647"
                         maxStringContentLength="2147483647"
                         maxArrayLength="2147483647"
                         maxBytesPerRead="2147483647"
                         maxNameTableCharCount="2147483647"/>
          <security mode="None" />
        </binding>
      </webHttpBinding>
    </bindings>
    <behaviors>
      <endpointBehaviors>
        <behavior name="defaultEndpointBehavior">
          <webHttp/>
        </behavior>
      </endpointBehaviors>
      <serviceBehaviors>
        <behavior name="defaultServiceBehavior">
          <serviceMetadata httpGetEnabled="true" />
          <serviceDebug includeExceptionDetailInFaults="true" />
        </behavior>
      </serviceBehaviors>
    </behaviors>
    <services>
      <service name="UploadSvc.UploadService" behaviorConfiguration="defaultServiceBehavior">
        <endpoint address="" behaviorConfiguration="defaultEndpointBehavior"
          binding="webHttpBinding" contract="UploadSvc.IUploadService"/>
      </service>
    </services>    
  </system.serviceModel>
 <system.webServer>
    <modules runAllManagedModulesForAllRequests="true"/>
  </system.webServer>
</configuration>

消费者.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Cache;
using System.Text;
namespace UploadSvcConsumer
{
    class Program
    {
        static void Main(string[] args)
        {
            //WebClient client = new WebClient();
            //client.UploadData("http://localhost:1208/UploadService.svc/Upload",)
            //string path = Path.GetFullPath(".");
            byte[] bytearray=null ;
            //throw new NotImplementedException();
            Stream stream =
                new FileStream(
                    @"C:'Image'hanuman.jpg"
                    FileMode.Open);
                stream.Seek(0, SeekOrigin.Begin);
                bytearray = new byte[stream.Length];
                int count = 0;
                while (count < stream.Length)
                {
                    bytearray[count++] = Convert.ToByte(stream.ReadByte());
                }
            string baseAddress = "http://localhost:1208/UploadService.svc/";
            HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(baseAddress + "Upload");
            request.Method = "POST";
            request.ContentType = "text/plain";
            request.KeepAlive = false;
            request.ProtocolVersion = HttpVersion.Version10;
            Stream serverStream = request.GetRequestStream();
            serverStream.Write(bytearray, 0, bytearray.Length);
            serverStream.Close();
            using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
            {
                int statusCode = (int)response.StatusCode;
                StreamReader reader = new StreamReader(response.GetResponseStream());
            }
        }
    }
}
相关文章：