1

我正在尝试通过改装将图像从一个 Asp 网络核心后端上传到另一个。

await _repository.UploadImageAsync(userId,
    new StreamPart(file.OpenReadStream(), file.FileName, file.ContentType), extension);

Api

[Put("/image/{userId}")]
Task<Guid> UploadImageAsync(Guid userId, StreamPart stream, string extension);

接收控制器

[HttpPut("image/{userId}")]
public async Task<IActionResult> UploadImageAsync([FromRoute] Guid userId, StreamPart stream, string extension)
{
    return await RunAsync(async () =>
    {
        var id = await _userImageManager.UploadImageAsync(userId, stream.Value, extension);

        return Ok(id);
    });
}

一旦我运行它，我就会得到以下异常：

Newtonsoft.Json.JsonSerializationException: Error getting value from 'ReadTimeout' on 'Microsoft.AspNetCore.Http.ReferenceReadStream'.
 ---> System.InvalidOperationException: Timeouts are not supported on this stream.
   at System.IO.Stream.get_ReadTimeout()
   at lambda_method(Closure , Object )
   at Newtonsoft.Json.Serialization.ExpressionValueProvider.GetValue(Object target)
   --- End of inner exception stack trace ---
   at Newtonsoft.Json.Serialization.ExpressionValueProvider.GetValue(Object target)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.CalculatePropertyValues(JsonWriter writer, Object value, JsonContainerContract contract, JsonProperty member, JsonProperty property, JsonContract& memberContract, Object& memberValue)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeValue(JsonWriter writer, Object value, JsonContract valueContract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerProperty)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.Serialize(JsonWriter jsonWriter, Object value, Type objectType)
   at Newtonsoft.Json.JsonSerializer.SerializeInternal(JsonWriter jsonWriter, Object value, Type objectType)
   at Newtonsoft.Json.JsonSerializer.Serialize(JsonWriter jsonWriter, Object value, Type objectType)
   at Newtonsoft.Json.JsonConvert.SerializeObjectInternal(Object value, Type type, JsonSerializer jsonSerializer)
   at Newtonsoft.Json.JsonConvert.SerializeObject(Object value, Type type, JsonSerializerSettings settings)
   at Newtonsoft.Json.JsonConvert.SerializeObject(Object value, JsonSerializerSettings settings)
   at Refit.JsonContentSerializer.SerializeAsync[T](T item) in d:\a\1\s\Refit\JsonContentSerializer.cs:line 34
   at Refit.RequestBuilderImplementation.<>c__DisplayClass17_0.<<BuildRequestFactoryForMethod>b__0>d.MoveNext() in d:\a\1\s\Refit\RequestBuilderImplementation.cs:line 546
--- End of stack trace from previous location where exception was thrown ---
   at Refit.RequestBuilderImplementation.<>c__DisplayClass14_0`2.<<BuildCancellableTaskFuncForMethod>b__0>d.MoveNext() in d:\a\1\s\Refit\RequestBuilderImplementation.cs:line 243

我尝试按照此处描述的方式进行操作，但没有成功。是不是我做错了什么？

编辑

基于@TomO的回答，我编辑了我的代码，但我仍然得到 null stream：

Api 1（发送到 Api 2 的部分）：

public async Task<Guid> UploadImageAsync(Guid userId, IFormFile file)
{
    ...
    var stream = file.OpenReadStream();

    var streamPart = new StreamPart(stream, file.FileName, file.ContentType);
    var response = await _repository.UploadImageAsync(userId,
                streamPart, extension);
    ...
}

Api 2（接收器）：

[HttpPost("image/{userId}")]
public async Task<IActionResult> UploadImageAsync([FromRoute] Guid userId, string description, IFormFile stream, string extension)
{
    ...
}

改装 API：

[Multipart]
[Post("/image/{userId}")]
Task<Guid> UploadImageAsync(Guid userId, [AliasAs("Description")] string description, [AliasAs("File")] StreamPart stream, string extension);
4

1 回答 1

2

我认为文档（以及问题中链接的解决方案）提供了很好的指导。但无论如何，这就是我要做的工作：

接收 API 端点：

[HttpPost]
[Route("{*filePath:regex(^.*\\.[[^\\\\/]]+[[A-Za-z0-9]]$)}")]
public async Task<IActionResult> AddFile([FromRoute] AddFileRequest request,
                                         [FromForm] AddFileRequestDetails body,
                                         CancellationToken cancellationToken)

以及相应的改装客户端调用：

[Multipart]
[Post("/{**filePath}")]
Task AddFile(string filePath, [AliasAs("Description")] string description, [AliasAs("File")] StreamPart filepart);

这里重要的是表单主体（不包括文件）的所有成员属性都必须使用“AliasAs”属性进行修饰。

在发送方调用：

            System.IO.Stream FileStream = request.File.OpenReadStream();
            StreamPart sp = new StreamPart(FileStream, request.FileName);

            try
            {
                await _filesClient.AddFile(request.FilePath, request.Description, sp);
            }
            catch (ApiException ae)
            {
                ...
                throw new Exception("Refit FileClient API Exception", ae);
            }

希望这可以帮助下一个人...

于 2020-04-23T16:38:24.787 回答