c# - Stream 意外结束，内容可能已被另一个组件读取。 Microsoft.AspNetCore.WebUtilities.MultipartReaderStream

Question

当我尝试从请求中读取多部分内容时出现异常，提示该内容可能已被另一个组件读取。

 if (MultipartRequestHelper.IsMultipartContentType(Request.ContentType))
            {
                // Used to accumulate all the form url encoded key value pairs in the 
                // request.
                var formAccumulator = new KeyValueAccumulator();

                var boundary = Request.GetMultipartBoundary();
                var reader = new MultipartReader(boundary, HttpContext.Request.Body);
                var section = await reader.ReadNextSectionAsync();
                while (section != null)
                {
                    ContentDispositionHeaderValue contentDisposition;
                    var hasContentDispositionHeader =
                        ContentDispositionHeaderValue.TryParse(section.ContentDisposition, out contentDisposition);
                }
            }

Answer 1

在asp.net core 3中，你必须添加factories.RemoveType<FormFileValueProviderFactory>();给你的DisableFormValueModelBindingAttribute属性。

代码

[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method)]
public class DisableFormValueModelBindingAttribute : Attribute, IResourceFilter
{
    public void OnResourceExecuting(ResourceExecutingContext context)
    {
        var factories = context.ValueProviderFactories;
        factories.RemoveType<FormValueProviderFactory>();
        factories.RemoveType<FormFileValueProviderFactory>();
        factories.RemoveType<JQueryFormValueProviderFactory>();
    }

    public void OnResourceExecuted(ResourceExecutedContext context)
    {
    }
}

Documentation