标签：sync wait attr rri control res tin var void
asp.net core MVC 过滤器会在请求管道的各个阶段触发。同一阶段又可以注册多个范围的过滤器，例如Global范围，controller范围等。以ActionFilter为例，我们来看看过滤器的触发顺序。
public class GlobalActionFilter : IAsyncActionFilter { public async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next) { var factory = context.HttpContext.RequestServices.GetService<ILoggerFactory>(); var logger = factory.CreateLogger<GlobalActionFilter>(); logger.LogWarning("全局ActionFilter执行之前"); await next(); logger.LogWarning("全局ActionFilter执行之后"); } }
注解方式：
public class ControllerActionFilter : ActionFilterAttribute { public override async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next) { var factory = context.HttpContext.RequestServices.GetService<ILoggerFactory>(); var logger = factory.CreateLogger<GlobalActionFilter>(); logger.LogWarning("ControllerActionFilter执行之前"); await next(); logger.LogWarning("ControllerActionFilter执行之后"); } }
重写方式（在controller内重写OnActionExecutionAsync）
public override async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next) { var logger = _factory.CreateLogger<ValuesController>(); logger.LogWarning("Controller内部重写的actionFinter执行前"); await next(); logger.LogWarning("Controller内部重写的actionFinter执行后"); }
public void ConfigureServices(IServiceCollection services) { services.AddMvc(o => { o.Filters.Add<GlobalActionFilter>(); }); }
[ControllerActionFilter] public class ValuesController : Controller
[HttpGet] [ActionActionFilter] public IEnumerable<string> Get()
从结果可以看出，Controller重写 > 全局 > Controller > Action
过滤器的执行顺序不是一成不变的，aspNet Core 通过灵活的设计让我们可以手动自定义过滤器的执行顺序。要实现自定义过滤器执行顺序则需要实现IOrderedFilter接口，该接口定义一个int类型的Order属性，这个属性越大则执行顺序越滞后。
public class GlobalActionFilter : IAsyncActionFilter,IOrderedFilter { public int Order => 0;
[ControllerActionFilter(Order =-1)] public class ValuesController : Controller {
[HttpGet] [ActionActionFilter(Order =-2)] public IEnumerable<string> Get() {
此时的执行顺序：controller内部重写 > Action > controller > global
标签：sync wait attr rri control res tin var void
原文地址：http://www.cnblogs.com/huanent/p/7452066.html
