Question

我正在使用.net 4.0并尝试使用rest wcf服务上传文件，该服务使用名为upload的方法，并使用名为download的方法使用相同的rest服务下载它。有一个控制台应用程序将流数据发送到wcf服务，并从服务下载相同的控制台应用程序。控制台应用程序使用WebChannelFactory连接并使用该服务。

以下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，当我检查文件时，我注意到它在Kilobytes中的大小与从控制台应用程序发送的原始文件大小相同，但是当我打开文件时，它没有内容。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。所有数据都去了哪里？

我正在做fileStream.ReadByte()>0的原因是因为我在某处读到了当通过网络传输时，缓冲区长度无法找到（这就是为什么我在尝试获取长度时遇到异常的原因）服务upload方法中的流。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，因为它使用上面的上传代码下载我之前上传的文件，即使上传的文件大小只有200 KB，它的大小只有16 KB。

我的代码出了什么问题？任何帮助表示赞赏。

Answer 1

你可以更简单：

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（但现在结束时）。这意味着你的第二次读取都将失败（read变量将在你的循环中为0，并立即爆发）因为流现在已经结束了。

Answer 2

这里我创建了一个WCF REST服务。的 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; } } }

<强>的Web.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>

<强> Consumer.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()); } } } }

使用WCF休息文件上传下载

2 个答案: