在片段中更改文本视图文本

我在android中创建我的第一个应用程序，我使用抽屉布局和获取当前位置的服务，并将数据发送到Broadacast接收器，这应该是更新仪表板片段中的纬度和经度textview ，但是当updateDashLocation被调用时，我收到这个错误：由于：java.lang.NullPointerException：尝试在DashLatitude的空对象引用上调用虚拟方法'void android.widget.TextView.setText（java.lang.CharSequence）'。的setText（纬度）;和DashLongitude.setText（经度）;在片段中更改文本视图文本

片段代码

public class DashboardFragment extends Fragment { 


public DashboardFragment() { 
    // Required empty public constructor 
} 

View dashboardInflatedView; 
TextView DashLatitude,DashLongitude; 
String TAG = "GPSTracker"; 

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
         Bundle savedInstanceState) { 

    Toolbar toolbar = ((MainActivity)getActivity()).toolbar; 
    toolbar.setTitle("Dashboard"); 

    dashboardInflatedView = inflater.inflate(R.layout.fragment_dashboard, container, false); 
    DashLatitude = (TextView)dashboardInflatedView.findViewById(R.id.DashLatitude); 
    DashLongitude = (TextView)dashboardInflatedView.findViewById(R.id.DashLongitude); 

    return dashboardInflatedView; 
} 

public void updateDashLocation(String latitude, String longitude){ 

    //Log.d(TAG, "Update Dashboard Location"); 
    DashLatitude.setText(latitude); 
    DashLongitude.setText(longitude); 
}

}

如何我可以访问仪表盘碎片的元素时updateDashLocation叫？

来源

2016-11-30 Cristian

看起来像在创建片段视图之前调用updateDashLocation – diedu

您确定您的视图有合适的ID吗？ – LukeWaggoner

id是正确的！ updateDashLocation在创建片段后调用。删除现金后我重复测试，我收到导致：java.lang.NullPointerException：尝试调用虚拟方法'android.view.View android.view.View.findViewById（int）'对空引用对象，如果我把DashLatitude .setText（ “测试”）;在片段的onCreateView期间，文本正确更新...以某种方式，我无法在充气器后访问相同片段中的片段视图！任何人都可以帮助我？ – Cristian

尝试在updateDashLocation方法被调用时声明TextViews？

public class DashboardFragment extends Fragment { 

     public DashboardFragment() { 
      // Required empty public constructor 
     } 

     View dashboardInflatedView; 
     TextView DashLatitude,DashLongitude; 
     String TAG = "GPSTracker"; 

     @Override 
     public View onCreateView(LayoutInflater inflater, ViewGroup container, 
           Bundle savedInstanceState) { 

      Toolbar toolbar = ((MainActivity)getActivity()).toolbar; 
      toolbar.setTitle("Dashboard"); 

      dashboardInflatedView = inflater.inflate(R.layout.fragment_dashboard, container, false); 
      return dashboardInflatedView; 
     } 

     public void updateDashLocation(String latitude, String longitude){ 

      DashLatitude = (TextView)dashboardInflatedView.findViewById(R.id.DashLatitude); 
      DashLongitude = (TextView)dashboardInflatedView.findViewById(R.id.DashLongitude); 

      //Log.d(TAG, "Update Dashboard Location"); 
      DashLatitude.setText(latitude); 
      DashLongitude.setText(longitude); 
     }

来源

2016-11-30 17:22:41 JamesSwinton

我找到了解决办法，问题是主要活动，现在在广播接收器，当作为被传递坐标，代码：

// Define the callback for what to do when data is received 
private BroadcastReceiver locationReceiver = new BroadcastReceiver() { 

    @Override 
    public void onReceive(Context context, Intent intent) { 

     Log.d(TAG, "Broadcastreceiver Coordinates"); 

     int resultCode = intent.getIntExtra("resultCode", RESULT_CANCELED); 
     if (resultCode == RESULT_OK) { 
      Double latitude= intent.getDoubleExtra("latitude",0); 
      Double longitude= intent.getDoubleExtra("longitude",0); 

      DashboardFragment dashboardFrag = (DashboardFragment) 
        manager.findFragmentByTag("Dashboard"); 
      dashboardFrag .updateLocation(latitude.toString(),longitude.toString()); 
      Log.d(TAG, latitude.toString()+" --- "+longitude.toString()); 
     } 
    } 
};

我得到的片段，该标签和访问方法

来源

2016-12-02 10:07:48 Cristian

在片段中更改文本视图文本

回答

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