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如何将数据从“父母”Fragment传递给“孩子” Fragment？我已经看过如何在片段之间传递数据，但就我而言，我不能使用Activity.

在我的应用程序中，我有Activity一个Fragment通过单击Listitem. 创建一个类并从循环创建的数据创建类中获取持久数据Activity。在创建之后，它会创建几个Child-Fragment，每个都有不同的 Views，它们应该显示更新的数据。FragmentFragmentFragment

但我的问题是，我无法将数据Parentfragment从Childfragment. 我不确定它是传递问题还是Childfragment.

在我的情况下，“textValueView”和“mySeries”始终为空。为什么 ？

父片段

public class ScreenSlidePagerActivity extends Fragment {


    Bundle bundle = new Bundle();

    public boolean stop = false;

    private ServerFragment newServer;

   //Pager Widget for animation handeling
    private ViewPager mPager;

   //Pager Adapter provides the pages to view pager widget
    private PagerAdapter mPagerAdapter;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                        Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);


        ViewGroup sliderFragmentView = (ViewGroup)   inflater.inflate(R.layout.fragment_screen_slide, container, false);

        ConnectAndReadTask myTask = new ConnectAndReadTask(ScreenSlidePagerActivity.this , "opc.tcp://10.0.2.2:52520" +
            " - " + "mySinus", new NodeId(Integer.parseInt("2"), "mySinus"));
        myTask.execute(new String[]{"opc.tcp://10.0.2.2:52520"});


        // Initiate a ViewPager and a PagerAdapter
        mPager = (ViewPager) sliderFragmentView.findViewById(R.id.pager);
        mPagerAdapter = new ScreenSlidePagerAdapter(getFragmentManager());
        mPager.setAdapter(mPagerAdapter);

        return sliderFragmentView;

}

private class ScreenSlidePagerAdapter extends FragmentStatePagerAdapter {

    public ScreenSlidePagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
        switch(position){
            case 0:
                return newServer.newInstance("url","url","url");
            case 1:
                return new GaugeFragment();
            case 2:
                return new GaugeFragment();
            default:
                return new GaugeFragment();
        }

    }

    @Override
    public int getCount() {
        return 3;
    }
}

@Override
public void onDestroy() {
    stop = true;
    super.onDestroy();
}

/**
 *
 * @param value
 */

public void setData(String value)
{

    Log.d("ScreenSlide.SetData", value);
   // mCallback.onValueSelected(value);#
  bundle.putString("value", value);
    ServerFragment.create(value);
    newServer.setArguments(bundle);
   //newServer.setData(value);

}


@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    newServer = new ServerFragment();
}
}

孩子的片段

public class ServerFragment extends Fragment {

TextView urlTextView, nodeTextView, valueTextView;

public static String passValue;
//Graph
GraphView graphView;
public LineGraphSeries<DataPoint>mySeries;
private double graph2LastXValue = 5d;


public View myFragmentView;
public String url, namespace, nodeName;

public ServerFragment() {}


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

   myFragmentView  = inflater.inflate(R.layout.fragment_server, container, false);

    urlTextView = (TextView)myFragmentView.findViewById(R.id.urlTextView);
    nodeTextView = (TextView)myFragmentView.findViewById(R.id.nodeTextView);
    valueTextView = (TextView)myFragmentView.findViewById(R.id.valueTextView);



    //Graph
    graphView = (GraphView)myFragmentView.findViewById(R.id.graphView);
    mySeries = new LineGraphSeries<DataPoint>();

    mySeries.setColor(Color.RED);

    graphView.addSeries(mySeries);
    graphView.getViewport().setXAxisBoundsManual(true);
    graphView.getViewport().setMinX(0);
    graphView.getViewport().setMaxX(100);
    graphView.getViewport().setMinY(-20);
    graphView.getViewport().setMaxY(70);

    url = getArguments().getString("url");

    urlTextView.setText(getArguments().getString("url"));
    nodeTextView.setText(getArguments().getString("ns") + " | " + getArguments().getString("nodeName"));

    return myFragmentView;

}



public void setData() {


    Bundle bundle = this.getArguments();

    String value = bundle.getString("value");
    graph2LastXValue += 1d;
    try {
        mySeries.appendData(new DataPoint(graph2LastXValue, Double.parseDouble(value)),
                true, 200);
    }
    catch (Exception e)
    {
        Log.d("mySeries.appendData", e.getMessage());
    }

    try {
        valueTextView.setText(value);
    }

    catch (Exception e)
    {
        Log.d("valueTextView", e.getMessage());
    }




    Log.d("Serverfragment setData:" , value);
}



@Override
public void onStart() {
    super.onStart();

        setData();

}


@Override
public void onDestroy() {

    Log.d("ServerFragment", "disconnected");
    super.onDestroy();
}


@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

}


public static ServerFragment newInstance(String url, String ns, String nodeName) {

    ServerFragment sf = new ServerFragment();
    Bundle b = new Bundle();
    b.putString("url", url);
    b.putString("ns", ns);
    b.putString("nodeName", nodeName);



    sf.setArguments(b);

    return sf;
}

}
4

2 回答 2

0

通常的方法是将它从第一个 Fragment 传递到主机 Activity，然后它将它分派到第二个 Fragment。

我不知道你为什么不能这样做，但如果真的像你说的那样，你可以尝试使用 Jake Warton 的 Otto Bus 库，然后将你的两个片段订阅到总线。

class Fragment1 { 

  @Override
    public void onResume() {
        super.onResume();
        mBus.register(this);
    }

    @Override
    public void onPause() {
        mBus.unregister(this);
        super.onPause();
    }

    //let's assume you need to do it it on button click
    @Override
    public void onClick(View v) {
      mBus.post(new SomeDataEvent())
    }
} 
//======================

class Fragment2 { 

  @Override
    public void onResume() {
        super.onResume();
        mBus.register(this);
    }

    @Override
    public void onPause() {
        mBus.unregister(this);
        super.onPause();
    }

    //here we define method to handle your data
    @Subscribe
    public void onSomeData(SomeDataEvent object) {
      //do something with it
    }
}

在此处查看更多信息http://square.github.io/otto/

于 2016-03-17T13:01:11.350 回答
0

您可以使用您想要的数据作为参数向您的片段添加公共方法。然后您可以从父片段中调用此方法。您需要做的就是获取您创建的片段的引用。

您可以使用 mPagerAdapter.getItem(int position); 遍历您的片段；

您还可以在创建片段时向片段添加标识符，以便更容易区分它们。例如代替new GaugeFragment()你可以做的new GaugeFragment(identifierString)。现在每个片段都可以告诉您有关“谁”的信息。您还可以拥有不同类型的片段。

    PagerAdapter mPagerAdapter;
    ScreenSlidePagerAdapter screenSlidePagerAdapter;

    screenSlidePagerAdapter =  new ScreenSlidePagerAdapter(getFragmentManager());
    mPagerAdapter = screenSlidePagerAdapter;

稍后当您要设置数据时：

    int count = screenSlidePagerAdapter .getCount();
    for(int i=0;i<count;i++){
        Fragment fragment = screenSlidePagerAdapter .getItem(i);
        if(fragment instanceof GaugeFragment){
            ((GaugeFrament)fragment).gaugeFragmentMethod(data);
            break;
        }
        else if(fragment instanceof OtherTypeOfFragment){
            ((OtherTypeOfFragment)fragment).otherTypeOfFragmentMethod(data);
            break;
        }
    }
于 2016-03-17T13:12:41.863 回答