public class LightweightViewModel extends ViewModel {
    // 瞧！連背包都不帶
    private int clickCount=0;
    
    // 記錄用戶點(diǎn)擊次數(shù)
    public void recordClick() {
        clickCount++;
        System.out.println("點(diǎn)擊次數(shù)：" + clickCount);
    }
}

public class FeatureRichViewModel extends AndroidViewModel {
    // 看！它背著神奇的Application背包
    private SharedPreferences prefs;
    
    public FeatureRichViewModel(Application app) {
        super(app);
        // 從背包里取出共享首選項(xiàng)工具
        prefs = app.getSharedPreferences("user_prefs", Context.MODE_PRIVATE);
    }
    
    // 保存用戶設(shè)置
    public void saveUserSetting(String key, String value) {
        prefs.edit().putString(key, value).apply();
        System.out.println("已保存設(shè)置：" + key + "=" + value);
    }
}

// 使用哥哥ViewModel正合適
public class ClickCounterViewModel extends ViewModel {
    private MutableLiveData<Integer> count = new MutableLiveData<>(0);
    
    public void increaseCount() {
        count.setValue(count.getValue() + 1);
    }
}

// 請(qǐng)出弟弟AndroidViewModel
public class ThemeViewModel extends AndroidViewModel {
    private SharedPreferences prefs;
    
    public ThemeViewModel(Application app) {
        super(app);
        prefs = app.getSharedPreferences("theme_prefs", 0);
    }
    
    public void saveTheme(String themeName) {
        prefs.edit().putString("current_theme", themeName).apply();
    }
}

// 通過(guò)參數(shù)傳遞工具（代替使用AndroidViewModel）
public class SafePrefsViewModel extends ViewModel {
    private SharedPreferences prefs;
    
    // 安全地獲取工具而不背背包
    public SafePrefsViewModel(SharedPreferences prefs) {
        this.prefs = prefs;
    }
}