Question

所以我尝试在我的应用中使用this Intro Slider

一切都很好，直到我试图让它出现在第一次开始。

我为此使用了 sharedPreferences 。

这是我的IntroActivity：

public class MainIntroActivity extends com.heinrichreimersoftware.materialintro.app.IntroActivity {

    private PrefManager prefManager;

    @Override protected void onCreate(Bundle savedInstanceState) {

        prefManager = new PrefManager(this);
        if (!prefManager.isFirstTimeLaunch()) {
            launchHomeScreen();
            finish();
        }

        super.onCreate(savedInstanceState);

        addSlide(new SimpleSlide.Builder()
            .title(R.string.intro_title1)
            .description(R.string.intro_description1)
            .image(R.drawable.tired)
            .background(R.color.colorPrimaryLight)
            .backgroundDark(R.color.colorPrimaryDark)
            .build());
    }


    private void launchHomeScreen() {
        prefManager.setFirstTimeLaunch(false);
        startActivity(new Intent(MainIntroActivity.this, MainActivity.class));
        finish();
    }

}

这是我的PrefManager类：

public class PrefManager {
    SharedPreferences pref;
    SharedPreferences.Editor editor;
    Context _context;

    // shared pref mode
    int PRIVATE_MODE = 0;

    // Shared preferences file name
    private static final String PREF_NAME = "MainIntroActivity";

    private static final String IS_FIRST_TIME_LAUNCH = "IsFirstTimeLaunch";

    public PrefManager(Context context) {
        this._context = context;
        pref = _context.getSharedPreferences(PREF_NAME, PRIVATE_MODE);
        editor = pref.edit();
    }

    public void setFirstTimeLaunch(boolean isFirstTime) {
        editor.putBoolean(IS_FIRST_TIME_LAUNCH, isFirstTime);
        editor.commit();
    }

    public boolean isFirstTimeLaunch() {
        return pref.getBoolean(IS_FIRST_TIME_LAUNCH, true);
    }
}

logcat：

Caused by: java.lang.NullPointerException
                      at com.heinrichreimersoftware.materialintro.app.IntroActivity.findViews(IntroActivity.java:282)
                      at com.heinrichreimersoftware.materialintro.app.IntroActivity.onCreate(IntroActivity.java:174)
                      at ege.ege.MainIntroActivity.onCreate(MainIntroActivity.java:21)

Answer 1

在super.onCreate(savedInstanceState);

之前移动prefManager = new PrefManager(this);

试图让我的Intro Slider只出现一次，但得到NullPointerException

1 个答案: