Question

我有以下过滤器属性，我可以将字符串数组传递给属性，如[MyAttribute("string1", "string2")]。

public class MyAttribute : TypeFilterAttribute
{
    private readonly string[] _ids;

    public MyAttribute(params string[] ids) : base(typeof(MyAttributeImpl))
    {
        _ids = ids;
    }

    private class MyAttributeImpl : IActionFilter
    {
        private readonly ILogger _logger;

        public MyAttributeImpl(ILoggerFactory loggerFactory)
        {
            _logger = loggerFactory.CreateLogger<MyAttribute>();
        }

        public void OnActionExecuting(ActionExecutingContext context)
        {
            // HOW DO I ACCESS THE IDs VARIABLE HERE ???
        }

        public void OnActionExecuted(ActionExecutedContext context)
        {
        }
    }
}

如何将字符串数组_ids传递给动作过滤器的实现？我错过了一些非常明显的东西！？

Answer 1

TypedFilterAttribute有一个Argument属性（类型为object[]），您可以在其中将参数传递给实现的构造函数。因此，您可以使用此代码：

public class MyAttribute : TypeFilterAttribute
{        
    public MyAttribute(params string[] ids) : base(typeof(MyAttributeImpl))
    {
        Arguments = new object[] { ids };
    }

    private class MyAttributeImpl : IActionFilter
    {
        private readonly string[] _ids;
        private readonly ILogger _logger;

        public MyAttributeImpl(ILoggerFactory loggerFactory, string[] ids)
        {
            _ids = ids;
            _logger = loggerFactory.CreateLogger<MyAttribute>();
        }

        public void OnActionExecuting(ActionExecutingContext context)
        {
            // NOW YOU CAN ACCESS _ids
            foreach (var id in _ids)
            {
            }
        }

        public void OnActionExecuted(ActionExecutedContext context)
        {
        }
    }
}

如何在asp.net中的动作过滤器中添加参数？

1 个答案: