Question

只是想知道，谷歌搜索如何在asp mvc 4中使用过滤器。我发现有些人像这样定义它们：

public class CustomFilter : ActionFilterAttribute

有些人喜欢这样：

public class CustomFilter : ActionFilterAttribute, IActionFilter

ActionFilterAttribute已经覆盖了所有操作，为什么我也应该实现这个接口？

另外例如在下一个代码中，最后再次调用过滤器，为什么会这样？

public class 

CustomActionFilter : ActionFilterAttribute, IActionFilter
{
    void IActionFilter.OnActionExecuting(ActionExecutingContext filterContext)


    {
        // TODO: Add your acction filter's tasks here

        // Log Action Filter Call
        MusicStoreEntities storeDB = new MusicStoreEntities();

        ActionLog log = new ActionLog()
        {
            Controller = filterContext.ActionDescriptor.ControllerDescriptor.ControllerName,
            Action = filterContext.ActionDescriptor.ActionName + " (Logged By: Custom 

Action Filter)",
            IP = filterContext.HttpContext.Request.UserHostAddress,
            DateTime = filterContext.HttpContext.Timestamp
        };

        storeDB.ActionLogs.Add(log);
        storeDB.SaveChanges();

        this.OnActionExecuting(filterContext);
    }
}

Answer 1

如果您检查MSDN definition of ActionFilterAttribute ，您将看到它是一个继承接口 IActionFilter AND IResultFilter 的抽象类。

实际上继承自 ActionFilterAttribute ，

public class CustomFilter : ActionFilterAttribute

相当于继承类 FilterAttribute 和接口 IActionFilter 和 IResultFilter

public class CustomFilter : FilterAttribute, IActionFilter, IResultFilter

与

无异

public class CustomFilter : ActionFilterAttribute, IActionFilter, IResultFilter

因此，继承自 ActionFilterAttribute 与继承 ActionFilterAttribute 和 IActionFilter 无异。

ASP MVC过滤器，实现接口与否？

1 个答案: