Question

我有以下接收类型T的Generic类，并且必须实现IEnumerable：

public class ConfigurationHelper<T>: IEnumerable<object[]> where T: BaseTestConfiguration 
{
    public T _configuration;

    public ConfigurationHelper(configuration)
    {
        _configuration = configuration;
    }

    public IEnumerator<object[]> GetEnumerator()
    {
        ParameterExpression element = Expression.Parameter(typeof(T), "element");
        //use reflection to check the property that's a generic list
        foreach (PropertyInfo property in _configuration.GetType().GetGenericArguments()[0].GetProperties())
        {
        }

       /* HERE IS MY ISSUE */
       return _configuration.Select(x=>GET LIST<OTHERTYPE> PROPERTY)
                            .SelectMany(i => new object[] { AS MANY PROPERTIES AS OTHERTYPE  })
                            .GetEnumerator();
    }

    IEnumerator IEnumerable.GetEnumerator()
    {
        return GetEnumerator();
    }
}

我从类型T中知道的唯一一件事就是只有一个属性类型List<OtherType>，我希望在此OtherType中返回一个IEnumerable<object[]>项和属性一样多的项目。

我想使用ExpressionTrees，但我不知道如何撰写它。

Answer 1

如果没有BestTestConfiguration的定义，真的无法做多少事情。如果你能提供，我会改变代码。请根据我的理解检查以下代码我尝试做的事情：

class Program
    {
        public static void Main(string[] args)
        {
            var helper = new ConfigurationHelper<BestTestConfiguration>(new BestTestConfiguration()
            {
                Objects = new List<string>()
                {
                    "testing 1",
                    "testing 2"
                }
            });
            var item = helper.GetEnumerator();
            Console.ReadLine();
        }


    }

    public class ConfigurationHelper<T> : IEnumerable<object[]> where T : BestTestConfiguration
    {
        public T Configuration;

        public ConfigurationHelper(T configuration)
        {
            Configuration = configuration;
        }

        public IEnumerator<object[]> GetEnumerator()
        {
            ParameterExpression element = Expression.Parameter(typeof(T), "element");
            //use reflection to check the property that's a generic list
            var items = new List<object[]>();

            foreach (PropertyInfo property in Configuration.GetType().GetProperties().Where(x => x.PropertyType.IsGenericType))
            {
                var valueOfProperty = Configuration.GetType().GetProperty(property.Name).GetValue(Configuration, null);
                items.Add(new object[] {valueOfProperty});
            }

            return items.GetEnumerator();
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }
    }

    public class BestTestConfiguration
    {
        public List<string> Objects { get; set; }
    }

ExpressionTree和IEnumerable实现

1 个答案: