详解ASP.NET Core WebApi 返回统一格式参数

业务场景：

业务需求要求，需要对 WebApi 接口服务统一返回参数，也就是把实际的结果用一定的格式包裹起来，比如下面格式：

{
 "response":{
 "code":200,
 "msg":"Remote service error",
 "result":""
 }
}

具体实现：

using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Filters;

public class WebApiResultMiddleware : ActionFilterAttribute
{
 public override void OnResultExecuting(ResultExecutingContext context)
 {
 //根据实际需求进行具体实现
 if (context.Result is ObjectResult)
 {
 var objectResult = context.Result as ObjectResult;
 if (objectResult.Value == null)
 {
 context.Result = new ObjectResult(new { code = 404, sub_msg = "未找到资源", msg = "" });
 }
 else
 {
 context.Result = new ObjectResult(new { code = 200, msg = "", result = objectResult.Value });
 }
 }
 else if (context.Result is EmptyResult)
 {
 context.Result = new ObjectResult(new { code = 404, sub_msg = "未找到资源", msg = "" });
 }
 else if (context.Result is ContentResult)
 {
 context.Result = new ObjectResult(new { code = 200, msg = "", result= (context.Result as ContentResult).Content });
 }
 else if (context.Result is StatusCodeResult)
 {
 context.Result = new ObjectResult(new { code = (context.Result as StatusCodeResult).StatusCode, sub_msg = "", msg = "" });
 }
 }
}

Startup添加对应配置：

public void ConfigureServices(IServiceCollection services)
{
 services.AddMvc(options =>
 {
 options.Filters.Add(typeof(WebApiResultMiddleware));
 options.RespectBrowserAcceptHeader = true;
 });
}