ASP.NET Core中的Filter的五种类型：

Authorization filter、

Resource filter、

Action filter、

Exception filter、

Result filter。

执行顺序：

Action Filter

1、IAsyncActionFilter接口

2、当有多个Action Filter，链式执行。

筛选器1 →next→ 筛选器2 →next→ 筛选器3

筛选器1 ←----- 筛选器2 ←----- 筛选器3

举例：

public class MyActionFilter1 : IAsyncActionFilter
{
	public async Task OnActionExecutionAsync(ActionExecutingContext context,ActionExecutionDelegate next)
	{
		Console.WriteLine("MyActionFilter 1:开始执行");
		ActionExecutedContext r = await next();
		Console.WriteLine("MyActionFilter 1:执行成功");
	}
}
public class MyActionFilter2 : IAsyncActionFilter
{
	public async Task OnActionExecutionAsync(ActionExecutingContext context, 
		ActionExecutionDelegate next)
	{
		Console.WriteLine("MyActionFilter 2:开始执行");
		ActionExecutedContext r = await next();
		Console.WriteLine("MyActionFilter 2:执行成功");
	}
}

注入服务：

builder.Services.Configure<MvcOptions>(options =>
{
    options.Filters.Add<MyActionFilter1>();
    options.Filters.Add<MyActionFilter2>();
});

请求方法：

[HttpGet]
public string GetFunction()
{
	Console.WriteLine("~~GetFunction方法~~");
	return "my func";
}

运行结果：

MyActionFilter 1:开始执行

MyActionFilter 2:开始执行

~~GetFunction方法~~

MyActionFilter 2:执行成功

MyActionFilter 1:执行成功