c# - 如何在 asp.net 中将参数添加到操作过滤器？

Question

我有以下过滤器属性，我可以像这样将一个字符串数组传递给属性 [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 Action 过滤器的实现？我是否遗漏了一些非常明显的东西!？

Answer 1

TypeFilterAttribute 有一个Argument 属性(object[] 类型)，您可以在其中将参数传递给实现的构造函数。因此适用于您的示例，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)
        {
        }
    }
}