在Startup.cs中定义Middleware，设置缓存Http请求的Body数据。代码如下。自定义Middleware请放到Configure方法的最前面。

app.Use(next => new RequestDelegate(async context => {context.Request.EnableBuffering();await next(context);})); 

GET请求

HttpContext.Request.Query
//或者
HttpContext.Request.QueryString

POST请求

form

HttpContext.Request.Form

body

HttpContext.Request.Body//过滤器中使用
public override async Task OnExceptionAsync(ExceptionContext context){var httpContext = context.HttpContext;var request = httpContext.Request;request.Body.Position = 0;StreamReader sr = new StreamReader(request.Body);string body = await sr.ReadToEndAsync();request.Body.Position = 0;}}

file

HttpContext.Request.Form.Files