Question

我正在尝试使用不同的标签创建一个记分视图，并在变量状态发生变化时更新每个标记。所以说我有这个类可以扩展可观察性，它有可分离的方法来改变生活，时钟，食物和健康的价值。这些方法还通知观察者，在我的情况下是得分视图。

import java.util.Observable;

import com.codename1.ui.Display;    
public class GameWorld extends Observable { 
            .....
            private int lives = 3; 
            private int clock = 10; 
            private int food = 0;
            private int health = 0;
            .....

            public void someMethodThatChangesValueOfLives {
                    lives--; //decreases lives
                    setChanged();
                    notifyObservers(lives);  
            }
            public void someMethodThatChangesValueOfClock {
                    clock++; //increases clock
                    setChanged();
                    notifyObservers(clock);  
            }
            public void someMethodThatChangesValueOfFood {
                    food += 30; //decreases lives
                    setChanged();
                    notifyObservers(food);  
            }
            public void someMethodThatChangesValueOfHealth {
                    health += 30; //decreases lives
                    setChanged();
                    notifyObservers(health);  
            }
    }

我的记分级别课程有不同的标签，用于存储生命，时钟，食物和健康。我的问题是我怎么想告诉更新方法更新哪个标签？说我的生活减少如何让它更新生命标签而不是时钟标签或其他标签？

import java.util.Observable;
import java.util.Observer;
import com.codename1.ui.Container;
import com.codename1.ui.Label;

    public class ScoreView extends Container implements Observer {
        private Label timeLabelText;
        private Label timeLabelValue;
        private Label livesLabelText;
        private Label livesLabelValue;
        private Label foodLabelText;
        private Label foodLabelValue;
        private Label healthLabelText;
        private Label healthLabelValue;
        ...more labels

        public ScoreView () {
            timeLabelText = new Label("Time:");
            timeLabelValue = new Label(" 0");
            livesLabelText = new Label("Lives Left:");
            livesLabelValue = new Label(" 3");
            foodLabelText = new Label("Food Level:");
            foodLabelValue = new Label("30");
            healthLabelText = new Label("Health Level:");
            healthLabelValue = new Label("10");
            ...more labels

            this.addComponent(timeLabelText);
            this.addComponent(timeLabelValue);
            ...add more labels to components
        }

        //How to tell update which label to update from the argument?
        public void update (Observable o, Object arg) {
            String clock = (String)arg;
            timeLabelValue.setText(clock);
            String lives = (String)arg;
            livesLabelValue.setText(lives);
            String food = (String)arg;
            foodLabelValue.setText(food);
            String health = (String)arg;
            healthLabelValue.setText(health);
}

Answer 1

属性非常适用于此，并且它们还具有其他一些便利功能。

https://www.codenameone.com/blog/tutorial-properties.html

如何使用观察者的更新方法来更新不同的标签？

1 个答案: