C＃如何製作泛型類？

Question

我該如何製作這個通用的？

class AtomicReference 
{ 
    private Object _value; 

    public AtomicReference() 
    { 
     _value = new Object(); 
    } 

    public AtomicReference(Object value) 
    { 
     OptimisticSet(value); 
    } 

    public Object CompareAndSet(Object newValue) 
    { 
     return Interlocked.Exchange(ref _value, newValue); 
    } 

    public void OptimisticSet(Object newValue) 
    { 
     do { 
     } while (_value == Interlocked.CompareExchange(ref _value, _value, newValue)); 
    } 

    public Object Get() 
    { 
     return _value; 
    } 
} 

我的失敗嘗試：

class AtomicReference<T> 
{ 
    private T _value; 

    public AtomicReference() 
    { 
    } 

    public AtomicReference(T value) 
    { 
     Set(value); 
    } 

    public T CompareAndSet(T newValue) 
    { 
     // _value is not an object that can be referenced 
     return Interlocked.Exchange(ref _value, newValue); 
    } 

    public void OptimisticSet(T newValue) 
    { 
     // I can't use the operator== with type T 
     do{}while(_value == CompareAndSet(newValue)); 
    } 

    public T Get() 
    { 
     return _value; 
    } 
} 

Answer 1

您需要constrainT是引用類型，像這樣：

class AtomicReference<T> where T : class { 
    private T _value; 

    public AtomicReference() { } 

    public AtomicReference(T value) { 
     OptimisticSet(value); 
    } 

    public T CompareAndSet(T newValue) { 
     return Interlocked.Exchange(ref _value, newValue); 
    } 

    public void OptimisticSet(T newValue) { 
     while (_value == CompareAndSet(newValue)); 
    } 

    public T Get() { 
     return _value; 
    } 
} 

編輯：我建議你也更換具有屬性的方法：

public T Value { 
    get { return _value; } 
    set { while(_value == CompareAndSet(value)); } 
} 

Answer 2

我沒有VS 2005年安裝在家裏幫助調試您的解決方案，但我認爲你需要限制T.這裏有一些一些資源，以幫助：

Generics C#

Generics Explained (.NET Framework version 2.0)