Android Studio-Fragment.setArguments（）返回空对象引用

Question

我有一个片段查看器的主要活动。主要活动从其他活动中获取附加内容，并应将这些附加内容设置为地图片段的参数。

但是，在fra.setArguments（message）;行上；该片段不存在，导致应用程序崩溃。

您能帮我解决吗？

public class MainScreen extends AppCompatActivity implements 
listFragment.SendMessage {

private Toolbar mToolbar;
private ViewPager mViewpager;
private PageAdapter mPageAdapter;
private TabLayout mTablayout;
public  Bundle message;

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

    mToolbar = (Toolbar) findViewById(R.id.mainToolbar);
    mViewpager = (ViewPager) findViewById(R.id.tabsViewPager);
    mTablayout = (TabLayout) findViewById(R.id.allTabs);

    setSupportActionBar(mToolbar);
    mPageAdapter = new PageAdapter(getSupportFragmentManager());
    mViewpager.setAdapter(mPageAdapter);
    mTablayout.setupWithViewPager(mViewpager);


    if(getIntent().getExtras()!= null) {
        message = new Bundle();
        message.putDouble("Lat",getIntent().getBundleExtra("Bundle").getDouble("Lat",0));
        message.putDouble("Long",getIntent().getBundleExtra("Bundle").getDouble("Long",0));
        String tag = "android:switcher:" + R.id.tabsViewPager + ":" + 0;
        mapFragment fra = (mapFragment) getSupportFragmentManager().findFragmentByTag(tag);
        fra.setArguments(message);

    }


}