Question

我面临的新的Android开发问题是我无法在相同活动的片段之间传递字符串值现在让我简要解释一下我的要求我有两个片段片段b和片段c。每当用户从片段c中的微调器中选择值时，我应该传递给片段c中的listview，到目前为止我尝试过：

这是我的Fragment New Requirement片段（片段c）：

package com.example.first.servicefirst;
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.Spinner;

public class NewRequirements extends Fragment {


@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    try {
        View view = inflater.inflate(R.layout.fragment_dialog_claim, container,
                false);
        final Button btnupdate;
        btnupdate = (Button) view.findViewById(R.id.update);
        final Spinner sbu = (Spinner) view.findViewById(R.id.sbuu);
        ArrayAdapter<CharSequence> adaptersbu = ArrayAdapter.createFromResource(
                getActivity().getBaseContext(), R.array.newrequirements, R.layout.spinnerlayout);
        adaptersbu.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        sbu.setAdapter(adaptersbu);
        final Spinner bu = (Spinner) view.findViewById(R.id.bu);

        adapterbu.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        bu.setAdapter(adapterbu);
        final Spinner sbuu = (Spinner) view.findViewById(R.id.sbu);
        ArrayAdapter<CharSequence> adaptersbuu = ArrayAdapter.createFromResource( 
        getActivity().getBaseContext(), R.array.newrequirements, R.layout.spinnerlayout);
        adaptersbuu.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        sbuu.setAdapter(adaptersbuu);
        final Spinner sc = (Spinner) view.findViewById(R.id.sc);
        ArrayAdapter<CharSequence> adaptersc = ArrayAdapter.createFromResource(
        getActivity().getBaseContext(), R.array.newrequirements, R.layout.spinnerlayout);
        adaptersc.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        sc.setAdapter(adaptersc);
        final Spinner ssc = (Spinner) view.findViewById(R.id.ssc);
        ArrayAdapter<CharSequence> adapterssc = ArrayAdapter.createFromResource
                (getActivity().getBaseContext(), R.array.newrequirements, R.layout.spinnerlayout);
        adapterssc.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        ssc.setAdapter(adapterssc);
        setHasOptionsMenu(true);
        final String str = sbu.getSelectedItem().toString();

        btnupdate.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                try {
                    Bundle bundle = new Bundle();
                    FragmentManager fm=getFragmentManager();
                    Add add = new Add();

                    bundle.putString("yes", str);
                    Log.i("Bundle", bundle.toString());
                    Log.v("Add", str);
                    add.setArguments(bundle);
                    FragmentTransaction ft=fm.beginTransaction();
                    ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
                    ft.replace(R.id.content_frame, add,"hi");
                    ft.addToBackStack(null);
                    ft.commit();


                }catch (Exception e){
                throw e;}
            }
        });
        return view;
    }catch (Exception e){
    throw e;
    }
 }

 }

这是片段添加（片段B）

  package com.example.first.servicefirst;

import android.app.Fragment;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Button;
 import android.widget.ListView;
import android.widget.Spinner;
import android.widget.TextView;

import java.util.ArrayList;


public  class Add extends Fragment implements View.OnClickListener
{
public static Add()
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.activity_btn_add, container, false);
    Spinner ldsource=(Spinner)rootView.findViewById(R.id.lead_source);
    ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
            getActivity().getBaseContext(), R.array.dropbox1, R.layout.spinnerlayout);


    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    ldsource.setAdapter(adapter);
 //   EditText editText=(EditText)rootView.findViewById(R.id.title);

    Spinner ldtype=(Spinner)rootView.findViewById(R.id.ldtype);
    ArrayAdapter<CharSequence> adapter1 = ArrayAdapter.createFromResource(
            getActivity().getBaseContext(), R.array.dropbox2,R.layout.spinnerlayout);

    adapter1.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    ldtype.setAdapter(adapter1);
    Spinner ldstatus=(Spinner)rootView.findViewById(R.id.ldstatus);
    TextView txt=(TextView)rootView.findViewById(R.id.spinnerTarget);
    ArrayAdapter<CharSequence> adapter2 = ArrayAdapter.createFromResource(
            getActivity().getBaseContext(), R.array.dropbox3, R.layout.spinnerlayout);

    adapter2.setDropDownViewResource(android.R.layout.simple_selectable_list_item);
    ldstatus.setAdapter(adapter2);
  //  Bundle bundle=getArguments();
  //  String good=bundle.getString("sbu");
    ArrayList<LdNewsItem> listContact = GetlistContact();
    final   ListView lv = (ListView)rootView.findViewById(R.id.ldrequirements);
    lv.setAdapter(new customListAdapterldrequirements(getActivity(), listContact));
//    lv.setOnTouchListener(new View.OnTouchListener() {
  //      @Override
    //    public boolean onTouch(View v, MotionEvent event) {
    //        return false;
       // }

        // Setting on Touch Listener for handling the touch inside ScrollView


    //});
sbu = getArguments().getString("yes");
     return rootView;


}

在以下位置获取空指针异常：sbu = getArguments（）。getString（“yes”）;真的Donno在哪里犯了错误，如果有人帮我提前谢谢你会非常有帮助！

Answer 1

如果您想在Fragment之间传递数据，可以使用以下方法。

1.您可以使用https://lodash.com/docs#findWhere使用此功能将数据发送到LBM，您可以在目标片段上实现接收器，以监听广播数据。

您可以在源片段和目标片段之间实现回调侦听器。使用回调侦听器源片段将在回调方法中传递数据，目标片段将侦听它。查找说明LocalBroadcastManager
您可以使用here第三方库在两个片段之间传递数据的简单方法。

Answer 2

执行此操作的最佳方法是使用Interface并处理Activity内的所有片段更改逻辑。我已经快速写了一些代码来告诉你这是如何工作的。我没有包含任何构造函数或Fragment实例化和填充代码。您必须在Fragment内保留对Activity FragmentTransaction的引用，并在那里处理public class MainActivity extends Activity implements FragmentOneListener { private FragmentOne fragmentOne; private FragmentTwo fragmentTwo; @Override public void sendDataBack(String data) { if (fragmentTwo != null) { fragmentTwo.doSomethingWithData(data); } } }。

如果您不知道如何做某事，请告诉我，我会尝试将其添加到示例代码中。

<强> MainActivity.java

public class FragmentOne extends Fragment {
    private FragmentOneListener fragmentOneListener;

    private void sendDataBack(String data) {
        if  (fragmentOneListener != null) {
            fragmentOneListener.sendDataBack(data);
        }
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        try {
          fragmentOneListener = (FragmentOneListener) context;
        } catch (ClassCastException e) {
            throw new ClassCastException(context.toString()+ " must implement FragmentOneListener");
        }
    }

    @Override
    public void onDetach() {
        super.onDetach();
        fragmentOneListener = null;
    }

    public interface FragmentOneListener {
        void sendDataBack(String data);
    }
}

FragmentOne.java

public class FragmentTwo extends Fragment {

    public void doSomethingWithData(String data) {

    }
}

<强> FragmentTwo.java

<svg xmlns:svg="http://www.w3.org/2000/svg" xmlns="http://www.w3.org/2000/svg">
    <g id="visibility-test">
        <rect x="100" y="0" height="140" width="40"/>
        <rect x="0" y="100" height="40" width="140" visibility="visible"/>
    </g>                
</svg>

如何在相同活动的片段之间传递值？

2 个答案: