我如何转换List< Interface>列出< Class>在C#中

问题描述：

我的接口定义为

public interface IReaderInfo
{
    string Displayname {get;}
}

和实现该接口的类

public class ReaderInfo : IReaderInfo
{
    string DisplayName {get;}
}

然后我创建了一个返回列表的函数

I then created a function which return List

public List<ReaderInfo> GetReaders
{
     var readers = new List<ReaderInfo>();
     var Ireaders = someobject.Getreaders();// Returns the list of IReaderInfo.
     // Now i would like cast Ireaders as readers and return.
}

我该如何投放?

答

您必须使用投放的项目创建新列表:

You have to create a new list with casted items:

var readers = Ireaders.Cast<ReaderInfo>().ToList();

或者，如果可能存在不兼容的IReaderInfo条目，而您只希望结果中包含实际的ReaderInfo对象:

Or, if there is a possibility to have incompatible IReaderInfo entries and you only want the actual ReaderInfo objects in the result:

var readers = Ireaders.OfType<ReaderInfo>().ToList();

我如何转换List< Interface>列出< Class>在C#中

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