getFragmentManager（）返回null，與android.support.v4.app.DialogFragment支持libraray

這裏是片段的對話框：getFragmentManager（）返回null，與android.support.v4.app.DialogFragment支持libraray

import android.support.v4.app.DialogFragment; 
public static class SensorMeasurmentsDialogFragment extends DialogFragment { 

    public static SensorMeasurmentsDialogFragment newInstance(int title) { 

     SensorMeasurmentsDialogFragment frag = new SensorMeasurmentsDialogFragment(); 
     Bundle args = new Bundle(); 
     args.putInt("title", title); 
     frag.setArguments(args); 
     return frag; 

     @Override public Dialog onCreateDialog(Bundle savedInstanceState) { 
      ..... 
     } 
    } 
}

它的呼叫從一個普通的活動做了不從fragmentActivity因爲我的活動已經擴展了mapActivity。

m_measurmentDlg=SensorMeasurmentsDialogFragment.newInstance(R.string.app_name); 
m_measurmentDlg.show(m_measurmentDlg.getFragmentManager(),"measurments");

任何想法爲什麼它是空的？

來源

2012-11-03 user1582281