.NetCoreAop之IActionFilter

一、简介

在.net core 中Filter分为以下六大类：

1、AuthorizeAttribute（权限验证）

2、IResourceFilter（资源缓存）

3、IActionFilter（执行方法前后的记录）

4、IResultFilter（结果生成前后扩展）

5、IAlwaysRun（响应结果的补充）

6、IExceptionFilter（异常处理）

 二、IActionFilter（同步）

1、定义Filter

public class CustomerActionFilterAttribute : Attribute, IActionFilter    {        /// <summary>        /// 在XXAction执行之前        /// </summary>        /// <param name="context"></param>        public void OnActionExecuting(ActionExecutingContext context)        {            Console.WriteLine("CustomerActionFilterAttribute.OnActionExecuting");        }        /// <summary>        /// 在XXAction执行之后        /// </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($"执行 {this.GetType().Name} 构造函数");        }        [CustomerActionFilter]        public IActionResult Index()        {            Console.WriteLine($"执行 Index 方法");            return View();        }    }

 3、扩展记录日志

public class CustomerActionFilterAttribute : Attribute, IActionFilter    {        private readonly ILogger<CustomerActionFilterAttribute> _logger;        public CustomerActionFilterAttribute(ILogger<CustomerActionFilterAttribute> logger)        {            _logger = logger;        }        /// <summary>        /// 在XXAction执行之前        /// </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($"当前请求的控制器是{controllerName},方法名{actionName},请求参数是{JsonConvert.SerializeObject(para)}");        }        /// <summary>        /// 在XXAction执行之后        /// </summary>        /// <param name="context"></param>        public void OnActionExecuted(ActionExecutedContext context)        {            var para = context.Result;            var controllerName = context.ActionDescriptor.RouteValues["controller"];            var actionName = context.ActionDescriptor.RouteValues["action"];            _logger.LogInformation($"当前请求的控制器是{controllerName},方法名{actionName},请求结果是{JsonConvert.SerializeObject(para)}");        }    }

public class Home1Controller : Controller    {        private readonly ILogger<HomeController> _logger;        public Home1Controller(ILogger<HomeController> logger)        {            _logger = logger;            Console.WriteLine($"执行 {this.GetType().Name} 构造函数");        }        [TypeFilter(typeof(CustomerActionFilterAttribute))]        public IActionResult Index(int id)        {            Console.WriteLine($"执行 Index 方法");            ViewBag.Data = new { name = "11111" };            return View();        }    }

 

 

 三、IAsyncActionFilter（异步）

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($"当前请求的控制器是{controllerName},方法名{actionName},请求参数是{JsonConvert.SerializeObject(para)}");                        var excuteContext = await next.Invoke(); // 这句话就是去执行Action            _logger.LogInformation($"当前请求的控制器是{controllerName},方法名{actionName},请求结果是{JsonConvert.SerializeObject(excuteContext.Result)}");        }    }

public class Home1Controller : Controller    {        private readonly ILogger<HomeController> _logger;        public Home1Controller(ILogger<HomeController> logger)        {            _logger = logger;            Console.WriteLine($"执行 {this.GetType().Name} 构造函数");        }        //[TypeFilter(typeof(CustomerActionFilterAttribute))]        [TypeFilter(typeof(CustomerAsyncActionFilterAttribute))]        public IActionResult Index(int id)        {            Console.WriteLine($"执行 Index 方法");            ViewBag.Data = new { name = "11111" };            return View();        }    }

 

 

 

 

四、总结

作用：该Filter可以记录Action执行前后的参数和结果

执行顺序：1、执行控制器的构造函数2、执行CustomerActionFilterAttribute.OnActionExecuting3、执行Action方法4、执行CustomerActionFilterAttribute.OnActionExecuted