这是我的设置,
class CostPeriodDto : IPeriodCalculation
{
public decimal? a { get; set; }
public decimal? b { get; set; }
public decimal? c { get; set; }
public decimal? d { get; set; }
}
interface IPeriodCalculation
{
decimal? a { get; set; }
decimal? b { get; set; }
}
class myDto
{
public List<CostPeriodDto> costPeriodList{ get; set; }
public List<IPeriodCalculation> periodCalcList
{
get
{
return this.costPeriodList; // compile error
}
}
}
这样做的最佳方式是什么？
解决方法
使用Cast< IPeriodCalculation>()：
public class CostPeriodDto : IPeriodCalculation
{
public decimal? a { get; set; }
public decimal? b { get; set; }
public decimal? c { get; set; }
public decimal? d { get; set; }
}
public interface IPeriodCalculation
{
decimal? a { get; set; }
decimal? b { get; set; }
}
public class myDto
{
public List<CostPeriodDto> costPeriodList { get; set; }
public List<IPeriodCalculation> periodCalcList
{
get
{
return this.costPeriodList.Cast<IPeriodCalculation>().ToList();
}
}
}
我相信C#4,如果你正在使用实现IEnumerable< out T>的东西,你可以按照你编写它的方式来做,它将使用Covariance来解决.
class myDto
{
public IEnumerable<CostPeriodDto> costPeriodList{ get; set; }
public IEnumerable<IPeriodCalculation> periodCalcList
{
get
{
return this.costPeriodList; // wont give a compilation error
}
}
}
