ASP.NET Core MVC （core 3.1)拦截器

1.三个类的代码放下面（可复制）

 2.ActionFilters

using Microsoft.AspNetCore.Mvc.Filters;
using Microsoft.Extensions.Logging;
 
namespace xx（更改一下命名空间）
{
    public class ActionFilters:ActionFilterAttribute
    {
        private readonly ILogger<ActionFilters> _logger;
        public ActionFilters(ILogger<ActionFilters> logger)
        {
            _logger = logger;
        }
        /// <summary>
        /// 执行方法之前
        /// </summary>
        /// <param name="context"></param>
        public override void OnActionExecuting(ActionExecutingContext context)
        {
            _logger.LogDebug("执行方法之前");
            base.OnActionExecuting(context);
        }
        /// <summary>
        /// 执行方法之后
        /// </summary>
        /// <param name="context"></param>
        public override void OnActionExecuted(ActionExecutedContext context)
        {
            _logger.LogDebug("执行方法之后");
            base.OnActionExecuted(context);
        }
        /// <summary>
        /// 返回值之前
        /// </summary>
        /// <param name="context"></param>
        public override void OnResultExecuting(ResultExecutingContext context)
        {
            _logger.LogDebug("返回值之前");
            base.OnResultExecuting(context);
        }
        /// <summary>
        /// 返回值之后
        /// </summary>
        /// <param name="context"></param>
        public override void OnResultExecuted(ResultExecutedContext context)
        {
            _logger.LogDebug("返回值之后");
            base.OnResultExecuted(context);
        }
    }
}

3.ExceptionFilters

using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Filters;
using Microsoft.AspNetCore.Mvc.ModelBinding;
using Microsoft.Extensions.Logging;
 
namespace xx(更改一下命名空间)
{
    /// <summary>
    /// 异常拦截器
    /// </summary>
    public class ExceptionFilters :ExceptionFilterAttribute
    {
        private readonly ILogger<ExceptionFilters> _logger;
        public IModelMetadataProvider ModelMetadata { get; }
        public ExceptionFilters(ILogger<ExceptionFilters> logger,IModelMetadataProvider modelMetadata)
        {
            _logger = logger;
            ModelMetadata = modelMetadata;
        }
        /// <summary>
        /// 当方法异常时进入
        /// </summary>
        /// <param name="context"></param>
        public override void OnException(ExceptionContext context)
        {
            if (!context.ExceptionHandled)
            {
                //添加到日志
                _logger.LogError(context.Exception.Message);
 
                //返回的数据
                //new{ 自定义 = false,自定义=context.Exception.Message 报错信息}里面的值对应你原本方法返回的数据类型的属性名
                context.Result = new JsonResult(new{ success = false,msg=context.Exception.Message});
 
                //终端式（跑到这里结束）
            }
            base.OnException(context);
        }
    }
}

4.ResultFilters

using System;
using System.Web.Mvc;
 
namespace xx（更改一下命名空间）
{
    public class ResultFilters : FilterAttribute, IResultFilter
    {
 
        void IResultFilter.OnResultExecuting(ResultExecutingContext filterContext)
        {
            //执行完action后跳转前执行
            throw new NotImplementedException();
        }
        void IResultFilter.OnResultExecuted(ResultExecutedContext filterContext)
        {
            //执行完action后跳转后执行
            throw new NotImplementedException();
        }
 
    }
   
}

5.指定方法拦截[TypeFilter(typeof(对应的拦截器类名))]（在运行时会自动进入对应方法）

 6.指定控制器拦截[TypeFilter(typeof(对应的拦截器类名))]相当于该控制器中所有方法都添加拦截器特性

 7.全局控制器中的所有方法添加拦截器（Startup类的ConfigureServices方法体中把拦截器添加到服务之中）

 
            #region 拦截器-全局
            services.AddControllersWithViews(configure =>
            {
                configure.Filters.Add<ActionFilters>();
            });

添加到全局就会每个控制器中方法都能实现拦截器的方法了