需要有关泛型方法的帮助 [英] Need help on generic methods

问题描述

我有2种方法，我打算将其重构为单一方法

I have 2 methods which I'm planning to refactor into a single method

IFactory _factory

// Method 1

TClass obj = (TClass )_factory.CreateA(param1);

// Method 2

HClass obj  = (HClass )__factory.CreateB(param2);

现在我想要一个通用方法，它会返回我的通用对象



下面是我试过的代码，但是徒劳无功。获取类型错误

Now I want a generic method which will return me generic object

Below is the code which I tried,But in vain.Get typecast error

T CreateInst<<T>>() 
{
    T _requestType;
        if(_requestType.GetType() == typeof(TClass ))
        {
             _requestType = (TClass)_factory.CreateA(param1)  ;
        }
        else if(_requestType.GetType() == typeof(HClass ))
        {
            _requestType = (HClass)_factory.CreateB(param1)  ;
        }

    return _requestType;
}

推荐答案

这是因为您的方法尝试分配类型的对象TClass 或 HClass 到 T 类型的对象。由于 T 没有约束 ， T 可以是任何东西，你不能分配 TClass 或 HClass 对任何事情......

That happens because your method tries to assign an object of type TClass or HClass to an object of type T. Since there are no constraints for T, T can be anything and, you cannot assign TClass or HClass to anything...

也许，你打算写下这样的话：

Maybe, you intended to write something like:

T CreateInst<T>(object param1) where T : class
{
    T _requestType = null;

    if(typeof(T) == typeof(TClass))
    {
        _requestType = _factory.CreateA(param1) as T  ;
    }
    else if(typeof(T) == typeof(HClass))
    {
        _requestType = _factory.CreateB(param1) as T ;
    }
 
    return _requestType;
}

T CreateInst<<T>>()
{
    T _requestType;
        if(_requestType is TClass)
        {
             _requestType = (TClass)_factory.CreateA(param1)  ;
        }
        else if(_requestType is HClass )
        {
            _requestType = (HClass)_factory.CreateB(param1)  ;
        }

    return _requestType;
}

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