c# - 我该如何修复这个 : generic type in list?

Question

我遇到编译错误:

"The type or namespace name 'T' could not be found (are you missing a using directive or an assembly reference?)
Error 3 The type or namespace name 'S' could not be found (are you missing a using directive or an assembly reference?)

下面是我的代码:

public static List<T> AutoCopyList(List<S> lst)
{
    List<T> ModelF = new List<T>();
    foreach (var item in lst)
    {
        var e = new T();
        e = Commn.AutoCopy<T, S>(item);
        ModelF.Add(e);
    }
    return ModelF;
}

Answer 1

您应该将您的方法标记为通用方法并明确声明 T 应该有一个公共(public)无参数构造函数:

 public static List<T> AutoCopyList<S,T>(List<S> lst) where T : new()

有关新约束的更多信息，where T : new()，请查看 here .