.Net Core Aop之IActionFilter

一、簡介

在.net core 中Filter分為以下六大類：

1、AuthorizeAttribute（權限驗證）

2、IResourceFilter（資源緩存）

3、IActionFilter（執行方法前后的記錄）

4、IResultFilter（結果生成前后擴展）

5、IAlwaysRun（響應結果的補充）

6、IExceptionFilter（異常處理）

 二、IActionFilter（同步）

1、定義Filter

public class CustomerActionFilterAttribute : Attribute, IActionFilter
    {
        /// <summary>
        /// 在XXAction執行之前
        /// </summary>
        /// <param name="context"></param>
        public void OnActionExecuting(ActionExecutingContext context)
        {
            Console.WriteLine("CustomerActionFilterAttribute.OnActionExecuting");
        }

        /// <summary>
        /// 在XXAction執行之后
        /// </summary>
        /// <param name="context"></param>
        public void OnActionExecuted(ActionExecutedContext context)
        {
            Console.WriteLine("CustomerActionFilterAttribute.OnActionExecuted");
        }

        
    }

 

2、使用Filter

public class Home1Controller : Controller
    {
        private readonly ILogger<HomeController> _logger;

        public Home1Controller(ILogger<HomeController> logger)
        {
            _logger = logger;
            Console.WriteLine($"執行 {this.GetType().Name} 構造函數");
        }


        [CustomerActionFilter]
        public IActionResult Index()
        {
            Console.WriteLine($"執行 Index 方法");
            return View();
        }
    }

 3、擴展記錄日志

public class CustomerActionFilterAttribute : Attribute, IActionFilter
    {

        private readonly ILogger<CustomerActionFilterAttribute> _logger;

        public CustomerActionFilterAttribute(ILogger<CustomerActionFilterAttribute> logger)
        {
            _logger = logger;
        }
        /// <summary>
        /// 在XXAction執行之前
        /// </summary>
        /// <param name="context"></param>
        public void OnActionExecuting(ActionExecutingContext context)
        {
            var para = context.HttpContext.Request.QueryString.Value;
            var controllerName = context.ActionDescriptor.RouteValues["controller"];
            var actionName = context.ActionDescriptor.RouteValues["action"];

            _logger.LogInformation($"當前請求的控制器是{controllerName},方法名{actionName},請求參數是{JsonConvert.SerializeObject(para)}");

        }

        /// <summary>
        /// 在XXAction執行之后
        /// </summary>
        /// <param name="context"></param>
        public void OnActionExecuted(ActionExecutedContext context)
        {
            var para = context.Result;
            var controllerName = context.ActionDescriptor.RouteValues["controller"];
            var actionName = context.ActionDescriptor.RouteValues["action"];
            _logger.LogInformation($"當前請求的控制器是{controllerName},方法名{actionName},請求結果是{JsonConvert.SerializeObject(para)}");

        }
    }

public class Home1Controller : Controller
    {
        private readonly ILogger<HomeController> _logger;

        public Home1Controller(ILogger<HomeController> logger)
        {
            _logger = logger;
            Console.WriteLine($"執行 {this.GetType().Name} 構造函數");
        }


        [TypeFilter(typeof(CustomerActionFilterAttribute))]
        public IActionResult Index(int id)
        {
            Console.WriteLine($"執行 Index 方法");
            ViewBag.Data = new { name = "11111" };
            return View();
        }
    }

 

 

 三、IAsyncActionFilter（異步）

public class CustomerAsyncActionFilterAttribute : Attribute, IAsyncActionFilter
    {

        private readonly ILogger<CustomerAsyncActionFilterAttribute> _logger;

        public CustomerAsyncActionFilterAttribute(ILogger<CustomerAsyncActionFilterAttribute> logger)
        {
            _logger = logger;
        }
        public async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)
        {

            var para = context.HttpContext.Request.QueryString.Value;
            var controllerName = context.ActionDescriptor.RouteValues["controller"];
            var actionName = context.ActionDescriptor.RouteValues["action"];

            _logger.LogInformation($"當前請求的控制器是{controllerName},方法名{actionName},請求參數是{JsonConvert.SerializeObject(para)}");
            
            var excuteContext = await next.Invoke(); // 這句話就是去執行Action

            _logger.LogInformation($"當前請求的控制器是{controllerName},方法名{actionName},請求結果是{JsonConvert.SerializeObject(excuteContext.Result)}");

        }
    }

public class Home1Controller : Controller
    {
        private readonly ILogger<HomeController> _logger;

        public Home1Controller(ILogger<HomeController> logger)
        {
            _logger = logger;
            Console.WriteLine($"執行 {this.GetType().Name} 構造函數");
        }


        //[TypeFilter(typeof(CustomerActionFilterAttribute))]
        [TypeFilter(typeof(CustomerAsyncActionFilterAttribute))]
        public IActionResult Index(int id)
        {
            Console.WriteLine($"執行 Index 方法");
            ViewBag.Data = new { name = "11111" };
            return View();
        }
    }

 

 

 

 

四、總結

作用：該Filter可以記錄Action執行前后的參數和結果

執行順序：
1、執行控制器的構造函數
2、執行CustomerActionFilterAttribute.OnActionExecuting
3、執行Action方法
4、執行CustomerActionFilterAttribute.OnActionExecuted