在asp.net中下載一個字節數組作爲文件mvc

我有一個字節數組，我嘗試下載爲一個docx文件。我允許用戶上傳多個文件並創建一個新的模型對象來存儲每個文件信息。然後我將編輯文件數據並返回給用戶一個新文件。現在我正嘗試從FileStreamResult的字節數組中下載文件。從我所看到和閱讀的同時使用FileStreamResult進行研究似乎被推薦。這是將字節數組作爲文件下載的最佳方式嗎？爲什麼我收到上傳方法返回時發生的錯誤？在asp.net中下載一個字節數組作爲文件mvc

我的HTML代碼是：

<html> 
<body> 
    <div class="jumbotron"> 
     <h1>File Upload through HTML</h1> 
     <form enctype="multipart/form-data" method="post" id="uploadForm" action="http://localhost:51906/api/FileUpload/Upload"> 
      <fieldset> 
       <legend>Upload Form</legend> 
       <ol> 
        <li> 
         <label>Upload File</label> 
         <input type="file" id="fileInput" name="fileInput" accept=".docx, .xml" multiple> 
        </li> 
        <li> 
         <input type="submit" value="Upload" id="submitBtn" class="btn"> 
        </li> 
       </ol> 
      </fieldset> 
     </form> 
    </div> 
</body> 
</html>

我的控制器代碼如下：

 [HttpPost] 
     public async Task<ActionResult> Upload() //Task<FileStreamResult> 
     { 
      if (!Request.Content.IsMimeMultipartContent()) 
      { 
       throw new Exception(); 
       return null; 
      } 

      var provider = new MultipartMemoryStreamProvider(); 
      await Request.Content.ReadAsMultipartAsync(provider); 

      List<FileUpload> fileList = new List<FileUpload>(); 
      foreach (var file in provider.Contents) 
      { 
       FileUpload f = new FileUpload //Create a new model 
       { 
        fileName = file.Headers.ContentDisposition.FileName.Trim('\"'), 
        contentType = file.Headers.ContentType.MediaType, 
        fileBuffer = await file.ReadAsByteArrayAsync()      
       }; 
       fileList.Add(f); 

//TEMPORARY FOR TESTING DOWNLOAD 
       if (f.contentType == "application/vnd.openxmlformats-officedocument.wordprocessingml.document") 
        final = new FileUpload 
        { 
         fileName = f.fileName, 
         contentType = f.contentType, 
         fileBuffer = f.fileBuffer 
        }; 
      } 

      //convert(fileList);   

      Stream stream = new MemoryStream(final.fileBuffer); 
      FileStreamResult fsr = new FileStreamResult(stream, "application/vnd.openxmlformats-officedocument.wordprocessingml.document") 
      { 
       FileDownloadName = "file.docx" 
      }; 
      return fsr; 
     }

我知道這一切，直到我在那裏創建流和FileStreamResult對象工作。然而，當我運行代碼，我得到這個結果：

<Error> 
    <Message>An error has occurred.</Message> 
    <ExceptionMessage> 
     The 'ObjectContent`1' type failed to serialize the response body for content type    'application/xml; charset=utf-8'. 
    </ExceptionMessage> 
    <ExceptionType> 
    System.InvalidOperationException 
    </ExceptionType> 
    <StackTrace/> 
    <InnerException> 
    <Message>An error has occurred.</Message> 
    <ExceptionMessage> 
     Type 'System.Web.Mvc.FileStreamResult' cannot be serialized. Consider marking it with the DataContractAttribute attribute, and marking all of its members you want serialized with the DataMemberAttribute attribute. If the type is a collection, consider marking it with the CollectionDataContractAttribute. See the Microsoft .NET Framework documentation for other supported types. 
    </ExceptionMessage> 
    <ExceptionType> 
    System.Runtime.Serialization.InvalidDataContractException 
    </ExceptionType> 
    <StackTrace> 
at System.Runtime.Serialization.DataContract.DataContractCriticalHelper.ThrowInvalidDataContractException(String message, Type type) 
     at System.Runtime.Serialization.DataContract.DataContractCriticalHelper.CreateDataContract(Int32 id, RuntimeTypeHandle typeHandle, Type type) 
     at System.Runtime.Serialization.DataContract.DataContractCriticalHelper.GetDataContractSkipValidation(Int32 id, RuntimeTypeHandle typeHandle, Type type) 
     at System.Runtime.Serialization.DataContractSerializer.GetDataContract(DataContract declaredTypeContract, Type declaredType, Type objectType) 
     at System.Runtime.Serialization.DataContractSerializer.InternalWriteObjectContent(XmlWriterDelegator writer, Object graph, DataContractResolver dataContractResolver) 
     at System.Runtime.Serialization.DataContractSerializer.InternalWriteObject(XmlWriterDelegator writer, Object graph, DataContractResolver dataContractResolver) 
     at System.Runtime.Serialization.XmlObjectSerializer.WriteObjectHandleExceptions(XmlWriterDelegator writer, Object graph, DataContractResolver dataContractResolver) 
     at System.Runtime.Serialization.DataContractSerializer.WriteObject(XmlWriter writer, Object graph) 
     at System.Net.Http.Formatting.XmlMediaTypeFormatter.WriteToStream(Type type, Object value, Stream writeStream, HttpContent content) 
     at System.Net.Http.Formatting.XmlMediaTypeFormatter.WriteToStreamAsync(Type type, Object value, Stream writeStream, HttpContent content, TransportContext transportContext) 
    --- End of stack trace from previous location where exception was thrown --- 
     at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) 
     at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) 
     at System.Runtime.CompilerServices.TaskAwaiter.GetResult() 
     at System.Web.Http.WebHost.HttpControllerHandler. 
     <WriteBufferedResponseContentAsync>d__14.MoveNext() 
    </StackTrace> 
    </InnerException> 
</Error>

來源

2014-07-23 user3780986