呼叫方法在主類的實例化對象

Question

我所試圖做的是這樣的：

public class MainClass { 
    private UIController uIController; 

    MainClass() { 
     uIController = new UIController(); 
    } 

    public void MethodIWantToCall() { 
     //Do Something 
    } 
} 

UIController類的例子：

public class UIController { 
    UIController() { 
     //Call a method in MainClass here, for example MethodIWantToCall() 
    } 

    public void MethodA { 
     //Call a method in MainClass here, for example MethodIWantToCall() 
    } 
} 

我想要做的是，UIController傳遞給MainClass命令，在用戶與UI交互時調用它的方法或將值返回給MainClass。

Answer 1

你需要一個MainClass實例的引用傳遞給您的UIController實例，例如：

public class UIController { 
    private final MainClass mainClass; 
    UIController (final MainClass mainClass) { 
     this.mainClass = mainClass; 
     //Call a method in MainClass here, for example MethodIWantToCall() 
     this.mainClass.MethodIWantToCall(); 
    } 

    public void MethodA() { 
     //Call a method in MainClass here, for example MethodIWantToCall() 
     this.mainClass.MethodIWantToCall();    
    } 
} 

然後

uIController = new UIController(this); 

PS：在Java方法應該與小寫開頭。

Answer 2

可以使實例字段：

public class MainClass { 
    public static MainClass instance; 
    public MainClass() { 
     instance=this; 
    } 
    public void method() {} 
} 

然後，調用：MainClass.instance.method（）;或：

public class MainClass { 
    public MainClass() { 
     new AnotherClass(this); 
    } 
    public void method() {} 
} 
public class AnotherClass { 
    public AnotherClass(MainClass main) { 
     main.method(); 
    } 
}