Question

我有以下通用类：

internal class AutoRegisterThread<T> where T: AutoRegisterAbstract
{
field1....
method1...
}

我有5个实现AutoRegisterAbstract的类（抽象类）。

在我的Main表单（内部局部类MainForm：Form）中，我需要声明一个字段：

AutoRegisterThread<> _currentThread

无需指定通用类型，因为我可以将_currentThread初始化为：

_currentThread=new AutoRegisterThread<implementedClass1>

或

_currentThread=new AutoRegisterThread<implementedClass2>

_currentThread：将在整个表单中使用（在许多情况下）

Answer 1

在C＃中具有通用类时，您必须提供type参数。您可以编写另一个不会通用的类。如果有任何逻辑可以在泛型和非泛型类之间共享，则可以将该逻辑移至另一个新类。

Answer 2

从非泛型基类继承：

internal abstract class AutoRegisterThreadBase { }

internal class AutoRegisterThread<T> : AutoRegisterThreadBase 
   where T: AutoRegisterAbstract
{
field1....
method1...
}

您的主表单字段现在可以为AutoRegisterThreadBase

类型

请注意，如果需要，非泛型父类可以与泛型类具有相同的名称；就您而言，AutoRegisterThread。

编辑：扩展示例，用法：

internal abstract class AutoRegisterThreadBase { /* Leave empty, or put methods that don't depend on typeof(T) */ }
internal abstract class AutoRegisterAbstract { /* Can have whatever code you need */ }

internal class AutoRegisterThread<T> : AutoRegisterThreadBase
    where T : AutoRegisterAbstract
{
    private int someField;
    public void SomeMethod() { }        
}

internal class AutoRegisterWidget : AutoRegisterAbstract { /* An implementation of AutoRegisterAbstract; put any relevant code here */ }

// A type that stores an AutoRegisterThread<T> (as an AutoRegisterThreadBase)
class SomeType
{
    public AutoRegisterThreadBase MyAutoRegisterThread { get; set; }
}

// Your code that uses/calls the above types
class Program
{        
    static void Main(string[] args)
    {
        var someType = new SomeType();

        // Any sub-class of AutoRegisterThreadBase, including generic classes, is valid
        someType.MyAutoRegisterThread = new AutoRegisterThread<AutoRegisterWidget>();

        // You can then get a local reference to that type 
        // in the code that's created it - since you know the type here
        var localRefToMyAutoRegisterThread = someType.MyAutoRegisterThread as AutoRegisterThread<AutoRegisterWidget>;
        localRefToMyAutoRegisterThread.SomeMethod();
    }
}

C＃-如何在不指定泛型类型的情况下在类型“泛型类”的MainForm类中声明变量

2 个答案: