如何通过声明名称引用局部变量

Question

如果我有按钮单击处理函数，我希望能够通过使用以下参数识别哪个按钮被其引用名称（例如minimize_button或maximize_button）和NOT单击：

minimize_button.setName("minimize_button"); 

class Game extends JFrame 
{ 
    public Game() 
    { 
     JButton minimize_button = new JButton(); 

     minimize_button.addMouseListener(new MouseAdapter() 
     { 
      public void mouseClicked(MouseEvent mouse) 
      { 
       setWindowState(mouse); 
      } 
     }); 

     JButton maximize_button = new JButton(); 

     maximize_button.addMouseListener(new MouseAdapter() 
     { 
      public void mouseClicked(MouseEvent mouse) 
      { 
       setWindowState(mouse); 
      } 
     }); 
    } 

    private void setWindowState(MouseEvent mouse) 
    { 
     int window_state = Game.this.getExtendedState(); 

     JButton button = (JButton)mouse.getComponent(); 

     if (button == minimize_button) 
     { 
      if (window_state == JFrame.NORMAL || window_state == JFrame.MAXIMIZED_BOTH) 
       window_state = JFrame.ICONIFIED; 
     } 
     else if (button == maximize_button) 
     { 
      if (window_state == JFrame.NORMAL) 
       window_state = JFrame.MAXIMIZED_BOTH; 
      else if (window_state == JFrame.MAXIMIZED_BOTH) 
       window_state = JFrame.NORMAL; 
     } 

     Game.this.setExtendedState(window_state); 
    } 
} 

注：我不想声明它作为类变量

编辑：我需要在一个函数中处理按钮点击的原因是因为我不想重复代码（见下文）。我不想如下：

class Game extends JFrame 
{ 
    public Game() 
    { 
     JButton minimize_button = new JButton(); 

     minimize_button.addMouseListener(new MouseAdapter() 
     { 
      public void mouseClicked(MouseEvent mouse) 
      { 
       int window_state = Game.this.getExtendedState(); 

       if (window_state == JFrame.NORMAL || window_state == JFrame.MAXIMIZED_BOTH) 
        Game.this.setExtendedState(JFrame.ICONIFIED); 
      } 
     }); 

     JButton maximize_button = new JButton(); 

     maximize_button.addMouseListener(new MouseAdapter() 
     { 
      public void mouseClicked(MouseEvent mouse) 
      { 
       int window_state = Game.this.getExtendedState(); 

       if (window_state == JFrame.NORMAL) 
        window_state = JFrame.MAXIMIZED_BOTH; 
       else if (window_state == JFrame.MAXIMIZED_BOTH) 
        window_state = JFrame.NORMAL; 

       Game.this.setExtendedState(window_state); 
      } 
     }); 
    } 
} 

注：好心从评论：“哦，你应该这样做这样”不要。我想知道的是，我可以通过它的参考名称引用一个变量。如果是这样，怎么样？在上面的例子中反射将不起作用，正如我所说的，我不想将它们声明为类变量。

Answer 1

在你的例子中，你试图访问范围之外的minimize_button和maximize_button。他们停止在你已经声明的Game（）构造函数之外“存在”。没有办法改变它。

另一种方法是将它们声明为类变量，即属性。你已经声明你不想要这个。

我可以建议让它编译的最小变化如下。我不会推荐这个，但它会在你确定的约束范围内回答你的问题。在这里，我已经通过最小化并最大化按钮引用到您的“共享”方法setWindowState（）中。

public Game() { 
    JButton minimize_button = new JButton(); 
    JButton maximize_button = new JButton(); 

    minimize_button.addMouseListener(new MouseAdapter() { 
     public void mouseClicked(MouseEvent mouse) { 
      setWindowState(mouse, minimize_button, maximize_button); 
     } 
    }); 

    maximize_button.addMouseListener(new MouseAdapter() { 
     public void mouseClicked(MouseEvent mouse) { 
      setWindowState(mouse, minimize_button, maximize_button); 
     } 
    }); 
} 

private void setWindowState(MouseEvent mouse, JComponent minimize_button, JComponent maximize_button) { 
    int window_state = Game.this.getExtendedState(); 
    JButton button = (JButton) mouse.getComponent(); 

    if (button == minimize_button) { 
     if (window_state == JFrame.NORMAL || window_state == JFrame.MAXIMIZED_BOTH) 
      window_state = JFrame.ICONIFIED; 
    } else if (button == maximize_button) { 
     if (window_state == JFrame.NORMAL) { 
      window_state = JFrame.MAXIMIZED_BOTH; 
     } else if (window_state == JFrame.MAXIMIZED_BOTH) { 
      window_state = JFrame.NORMAL; 
     } 
    } 
    Game.this.setExtendedState(window_state); 
}