Question

我打算使用LoadPreferences和SavePreferences方法。我希望它尽可能灵活，这样我就可以要求任何可爱的＆＃34; savable＆＃34;数据在我需要时被调用，并在我完成任何类/方法的更改时保存。当我像任何可返回变量一样设置它时，它会给我一个nullpointerexception。这就是我所拥有的：

public class MainActivity extends Activity {

// Add SharedPreference loader

int mPlayerCharisma = SharedPrefLoader("playerCharisma", 0); //I want variable
// playerCharisma if it exists, and to default to int 0 if it does not
int mPlayerBusiness = SharedPrefLoader("playerBusiness", 0);
int mPlayerCombat = SharedPrefLoader("playerCombat", 0);
int mPlayerLevel = SharedPrefLoader("playerLevel", 0);
int mPlayerLocation = SharedPrefLoader("playerLocation", 0);
int mPlayerMoney = SharedPrefLoader("playerMoney", 500);
int mPlayerEnergy = SharedPrefLoader("playerEnergy", 10);

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        // ...
    }

    public int SharedPrefLoader(String key, int defValue) {
        SharedPreferences sharedPref = this.getSharedPreferences("drudlordmt",
            MODE_PRIVATE); //This is where  my nullpointerexception points to//
        int returnedValue = sharedPref.getInt(key, defValue);
        return returnedValue;
    }

    public void SharedPrefSaver(String key, int value) {
        SharedPreferences settings = getSharedPreferences("druglordmt", 0);
        SharedPreferences.Editor prefEditor = settings.edit();
        prefEditor.putInt(key, value).commit();
    }
}

从我的阅读中我知道我需要以某种方式传递我的背景，但我想确保我仍然可以做我想要的事情。任何建议都将不胜感激。

谢谢！

Answer 1

移动：

int mPlayerCharisma = SharedPrefLoader("playerCharisma", 0); //I want variable
// playerCharisma if it exists, and to default to int 0 if it does not
int mPlayerBusiness = SharedPrefLoader("playerBusiness", 0);
int mPlayerCombat = SharedPrefLoader("playerCombat", 0);
int mPlayerLevel = SharedPrefLoader("playerLevel", 0);
int mPlayerLocation = SharedPrefLoader("playerLocation", 0);
int mPlayerMoney = SharedPrefLoader("playerMoney", 500);
int mPlayerEnergy = SharedPrefLoader("playerEnergy", 10);

在SharedPrefLoader()内

（以及对onCreate()的所有其他调用）。请参阅：Why getApplicationContext() in constructor of Activity throws null pointer exception?

从方法加载和保存SharedPreferences

1 个答案: