在实例化从泛型继承的类型时，有没有办法不使用动态? [英] Is there a way not to use dynamic when instantiating a type that inherits from generic?

问题描述

如何创建一个从泛型继承的类型的实例，并将其静态转换为其基类型

How can I create an instance a type that inherits from generic, and statically cast it to its base type

foreach(Type t in x.ChildType.Assembly.GetTypes())
{
    if (t.BaseType.IsGenericType)
    {
        if (t.BaseType.GetGenericTypeDefinition() == typeof(ClassMapExt<>)) 
        {
            if (t.BaseType.GetGenericArguments()[0] == x.ChildType) 
            {
                // t is BonusMap. BonusMap is declared as:
                // class BonusMap : ClassMapExt<Bonus>
                dynamic bz = Activator.CreateInstance(t);  

                // the last line is analogous to:
                // var bz = new BonusMap();

                // statically casting it doesn't work
                // var bz = (ClassMapExt<>) Activator.CreateInstance(t); 

                foreach (IManyToOneMappingProvider imt1 in bz.ExtReference)

推荐答案

通常的方法是在其中包含一个非通用 API(可能具有显式实现).然后你只需转换到非通用接口.

Normally the way to do that is to include a non-generic API in there (perhaps with explicit implementation). Then you just cast to the non-generic interface.

不完全一样，但有点像:

Not quite the same, but a bit like:

Type itemType = ...;
IList list = (IList)Activator.CreateInstance(
    typeof(List<>).MakeGenericType(itemType));
list.Add(...);

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