将TimePickerDialog的结果设置为通过DialogFragment的按钮android

Question

美好的一天，我会第一个承认，我没有使用片段的经验，只是学习，请耐心等待。正如标题所说，我试图将TimePickerDialog的结果设置为我的活动中的按钮，但没有成功。当我点击开始按钮时，我看不到一个通常的TimePickerDialog，我看到的只是屏幕中间的一个小空对话框。所以，请问我可能做错了什么？谢谢。

这里是我的代码：

TimeDialog：

public class TimeDialog extends DialogFragment { 
    private int mHour; 
    private int mMinute; 

    public TimeDialog(){ 

    } 

    public static TimeDialog newInstance(int title){ 
     TimeDialog frag = new TimeDialog(); 
     Bundle args = new Bundle(); 
     args.putInt("title", title); 
     frag.setArguments(args); 
     return null; 

    } 

    private TimePickerDialog.OnTimeSetListener mTimeSetListener = new TimePickerDialog.OnTimeSetListener() { 

     @Override 
      public void onTimeSet(TimePicker view, int hourOfDay, int minute) { 
       mHour = hourOfDay; 
       mMinute = minute; 

       //updateDisplay(); 
      } 

     /*private void updateDisplay() { 

      View v = getActivity().getLayoutInflater().inflate(R.layout.add_resp, null); 
      Button start = (Button)v.findViewById(R.id.start_time_button_id); 
      start.setText(new StringBuilder().append(mHour).append(":").append(mMinute).toString()); 


     }*/ 
     }; 

    @Override 
    public Dialog onCreateDialog(Bundle savedInstancestate){ 

     return new TimePickerDialog(getActivity(), mTimeSetListener, mHour, mMinute, false); 

    } 

    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){ 
     View v = inflater.inflate(R.layout.add_resp, container, false); 
     Button start = (Button)v.findViewById(R.id.start_time_button_id); 
     start.setText(new StringBuilder().append(mHour).append(":").append(mMinute).toString()); 
     return v; 

    } 
} 

和这里就是我称之为从活动：

public class AddResp extends Activity implements OnClickListener { 
    EditText text_title; 
    Button start; 

    public void onCreate(Bundle savedInstanceState){ 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.add_resp); 

     text_title = (EditText)findViewById(R.id.title_text_id); 
     start = (Button)findViewById(R.id.start_time_button_id); 

     start.setOnClickListener(this); 

    } 

    @Override 
    public void onClick(View view) { 
     int selection = view.getId(); 
     switch(selection){ 
     case R.id.start_time_button_id: 

      DialogFragment newFragment = new DialogFragment(); 
       newFragment.show(getFragmentManager(), "dialog"); 
     break;  
     } 
    } 
} 

Answer 1

对于来自DialogFragment将数据发送到活动，您可以使用Handler类。

的主要活性，从其中TimePicker对话框被称为：

public class MainActivity extends Activity{ 

    Handler h = new Handler(){ 
     @Override 
     public void handleMessage(Message msg){ 
      Button button = (Button) findViewById(R.id.btn); 
      button.setText(msg.getData().getString("btn")); 
     } 
    }; 

    @Override 
    public void onCreate(Bundle bundle){ 
     super.onCreate(bundle); 
     setContentView(R.layout.main); 
    } 

    public void btnClicked(View v){  
     TimepickerFragment dialog = new TimepickerFragment(h); 
     dialog.show(getFragmentManager(), "timepickerdialog"); 
    } 
} 

TimePicker对话框：

public class TimepickerFragment extends DialogFragment{ 
    Handler h; 
    public TimepickerFragment(Handler arg_h){ 
     h = arg_h;  
    }  
    private TimePickerDialog.OnTimeSetListener callback = new TimePickerDialog.OnTimeSetListener() { 

     @Override 
     public void onTimeSet(TimePicker view, int hourOfDay, int minute) {   
      Message msg = new Message(); 
      Bundle data = new Bundle(); 
      data.putString("btn", "Selected Time - " + hourOfDay + ":" + minute); 
      msg.setData(data); 
      h.sendMessage(msg);    
     } 
    }; 

    public Dialog onCreateDialog(Bundle bundle){ 
     int hourOfDay = 10; 
     int minute = 10; 
     boolean is24HourView = false; 
     TimePickerDialog tpdialog = new TimePickerDialog(getActivity(), callback, hourOfDay, minute, is24HourView); 
     return tpdialog; 
    } 
} 

注：上述代码在API级测试14