在ASP.NET MVC中有四种过滤器类型
Action
1、在ASP.NET MVC项目中，新建文件夹Filter，然后新建类MyCustormFilter，继承自ActionFilterAttribute类，我们来看下ActionFilterAttribute类有如下四个方法，从命名我应该就可以看出他们的执行时机。
?public class MyCustormFilter:ActionFilterAttribute ???{ ???????public override void OnActionExecuting(ActionExecutingContext filterContext) ???????{ ???????????filterContext.HttpContext.Response.Write("Action执行前"); ???????????base.OnActionExecuting(filterContext); ???????} ???????public override void OnActionExecuted(ActionExecutedContext filterContext) ???????{ ???????????filterContext.HttpContext.Response.Write("Action执行后"); ???????????base.OnActionExecuted(filterContext); ???????} ???}2、对于过滤器，我们可以把它们加在三个地方，一个是控制器上面（控制器下面的所有Action），一个是Action上面（指定标识的Action），另一个就是全局位置（所有控制器中的Action)。这里我只演示在Action上面加
[MyCustormFilter]
public ActionResult Index()
{
return View();
}
public ActionResult Index1()
{
return View();
??????}
3、build然后运行
Result
1、新建类TestResultFilter，继承ActionFilterAttribute
?public class TestResultFilter:ActionFilterAttribute ???{ ???????/// <summary> ???????/// 加载 "视图" 前执行 ???????/// </summary> ???????/// <param name="filterContext"></param> ???????public override void OnResultExecuting(System.Web.Mvc.ResultExecutingContext filterContext) ???????{ ???????????filterContext.HttpContext.Response.Write("加载视图前执行 OnResultExecuting <br/>"); ???????????base.OnResultExecuting(filterContext); ???????} ???????/// <summary> ???????/// 加载"视图" 后执行 ???????/// </summary> ???????/// <param name="filterContext"></param> ???????public override void OnResultExecuted(System.Web.Mvc.ResultExecutedContext filterContext) ???????{ ???????????filterContext.HttpContext.Response.Write("加载视图后执行 OnResultExecuted <br/>"); ???????????base.OnResultExecuted(filterContext); ???????} ???}2、这里我把TestResultFilter过滤器加在控制器上面
?[TestResultFilter] ???public class FilterTestController : Controller ???{ ??????[MyCustormFilter] ???????public ActionResult Index() ???????{ ???????????return View(); ???????} ??????public ActionResult Index1() ??????{ ??????????return View(); ??????} ???}3、运行看下结果
注意：Result过滤器，无论Action的返回类型为什么（甚至void）都将执行。
RouteData中保存了当前请求匹配的路由信息和路由对象
修改MyCustormFilter.cs
public override void OnActionExecuting(ActionExecutingContext filterContext) ???????{ ???????????//1.获取获取请求的类名和方法名 ???????????string strController = filterContext.RouteData.Values["controller"].ToString(); ???????????string strAction = filterContext.RouteData.Values["action"].ToString();//2.另一种方式 获取请求的类名和方法名 ???????????string strAction2 = filterContext.ActionDescriptor.ActionName; ???????????string strController2 = filterContext.ActionDescriptor.ControllerDescriptor.ControllerName; ???????????filterContext.HttpContext.Response.Write("Action执行前</br>"); ???????????filterContext.HttpContext.Response.Write("控制器:" + strController + "</br>"); ???????????filterContext.HttpContext.Response.Write("控制器:" + strController2+"</br>"); ???????????filterContext.HttpContext.Response.Write("Action:" + strAction + "</br>"); ???????????filterContext.HttpContext.Response.Write("Action:" + strAction2 + "</br>"); ???????????base.OnActionExecuting(filterContext); ???????}AuthorizeAttribute
1、 新建TestAuthorizeAttribute
???/// <summary> ???/// 授权过滤器 --在Action过滤器前执行 ???/// </summary> ???public class TestAuthorizeAttribute:AuthorizeAttribute ???{ ???????public override void OnAuthorization(AuthorizationContext filterContext) ???????{ ???????????filterContext.HttpContext.Response.Write("<br/>OnAuthorization<br/>"); ???????????//注释掉父类方法，因为父类里的 OnAuthorization 方法会调用asp.net的授权验证机制！ ???????????//base.OnAuthorization(filterContext); ???????}}2、在控制器FilterTest中的Index上添加TestAuthorize标记
??????[MyCustormFilter] ??????[TestAuthorize] ???????public ActionResult Index() ???????{ ???????????return View(); ???????}运行看下结果：
Exception
1、新建TestHandleError.cs
???/// <summary> ???/// 异常处理 过滤器 ???/// </summary> ???public class TestHandleError : HandleErrorAttribute ???{ ???????public override void OnException(ExceptionContext filterContext) ???????{ ???????????//1.获取异常对象 ???????????Exception ex = filterContext.Exception; ???????????//2.记录异常日志 ???????????//3.重定向友好页面 ???????????filterContext.Result = new RedirectResult("~/error.html"); ???????????//4.标记异常已经处理完毕 ???????????filterContext.ExceptionHandled = true; ???????????base.OnException(filterContext); ???????} ???}2、在Action上面加TestHandleError
?[TestHandleError] ??????public ActionResult GetErr() ??????{ ??????????int a = 0; ??????????int b = 1 / a; ??????????return View(); ??????}注意：通常这样的异常处理我们是放在全局过滤器上面的。
??public class FilterConfig ???{ ???????public static void RegisterGlobalFilters(GlobalFilterCollection filters) ???????{ ???????????//filters.Add(new HandleErrorAttribute()); ???????????//添加全局过滤器 ???????????filters.Add(new TestHandleError()); ???????} ???}ASP.NET MVC中有四种过滤器类型
原文地址：https://www.cnblogs.com/yy1234/p/8862061.html