c# - 是否可以传递服务过滤器参数？

Question

我知道使用常规过滤器可以传递如下参数:

[Filter(param="value")]
public ActionResult Action()
{
    return View();
}

public class Filter : ActionFilterAttribute
{
    public string param { get; set; }

    public override void OnActionExecuting(ActionExecutingContext filterContext)
    {
        // do something with your parameter...
    }       
}

我有一个服务过滤器:

// MyCustomFilter.cs    
namespace MyNamespace.Filters
{
    public class MyCustomFilter : ActionFilterAttribute
    {
        public string param { get; set; }

        // The services I'm injecting.
        private ILogger _logger;
        private IM3ObjectRepository _repo;

        public MyCustomFilter(ILogger<MyCustomFilter> logger, IM3ObjectRepository repo)
        {
            _logger = logger;
            _repo = repo;
        }

        public override void OnActionExecuting(ActionExecutingContext ctx)
        {
            _logger.LogInformation("Filter is working.");

            // Get stuff from object repository, based on passed-in parameter.
        }
    }
}

// Startup.cs
public void ConfigureServices(IServiceCollection services)
{
    ...

    services.AddSingleton<IM3ObjectRepository, M3ObjectRepository>();

    services.AddScoped<M3UISecurityFilter>();

    ...
}

public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
    loggerFactory.AddConsole(Configuration.GetSection("Logging"));
    loggerFactory.AddDebug();

    loggerFactory.AddSerilog();

    ...
}

// Example of filter being used.
[ServiceFilter(typeof(MyCustomFilter))]
public IActionResult Action(...)
{
    ...
}

过滤器中注入(inject)了一些服务。但是每次我使用该服务时，我也会发送一个参数。

我将如何实现传入参数？我在网上找不到任何描述如何与常规过滤器类似的方法。服务过滤器甚至可能吗？

Answer 1

TypeFilterAttribute正是为此而定义的。

就像 服务过滤属性 除了它允许您传递不一定从 IoC 容器解析的构造函数参数。

例子:

[TypeFilter(typeof(LogFilter), Arguments = new object[] {"myLogger"})]  
[HttpGet("")]
public IEnumerable<Item> Get()
{
    return this.repository.GetAll();
}

This article describes this neatly.