在这两个片段之间传递数据是不可能的

Question

我要疯了！！ 我无法将数据从片段（A）传递到另一个片段（B）。 我阅读了有关使用公共接口的信息......它似乎可以工作，但我不明白如何使用这种方法。

片段(A)

package it.anddev.pagertabs;
public class Page1Fragment extends Fragment {

String Str;
OnDataPass dataPasser;

Class Senddata extends AsyncTask<String, String, String> {

   @Override
   protected void onPreExecute() {

                            // do something [...]

   }

    @Override
    protected String doInBackground(String... args) {

                             // do something [...]

           dataPasser.onDataPass(result_array.toString());

    }

      return null;

    }

    protected void onPostExecute(String file_url) {

                             // do something [...]

    }};



@Override
public void onAttach(Activity activity) {
  super.onAttach(activity);
  dataPasser = (OnDataPass) activity;

}

public interface OnDataPass {
    public void onDataPass(String data);
}

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

                       // do something [...]

  Button Avanti = (Button) view.findViewById(R.id.sendbutton);
  Avanti.setOnClickListener(new OnClickListener() {
           @Override
           public void onClick(View view) {
               //mViewPager.setCurrentItem(1, true);
               new Senddata().execute();
           }
            });

片段B

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


  if (container == null) {
     return null;
  }

  View view = (LinearLayout)inflater.inflate(R.layout.page2,container,false);

  Button mostra = (Button) view.findViewById(R.id.mostrabutton);

           // String str = i need to get string from "public void onDataPass"

  mostra.setOnClickListener(new OnClickListener() {
       @Override
       public void onClick(View view) {
           //mViewPager.setCurrentItem(1, true);
           Log.d("IT WORKS", str);
       }
        });


  return view;
}

@Override
public void onDataPass(final String data) {
// TODO Auto-generated method stub
Log.d("okkkkkk", "" + data);

}

最后，我怎样才能从fragmentB 中的public void 中获取字符串？ 谢谢

Answer 1

考虑我的 2 个片段 A 和 B，假设我需要将数据从 B 传递到 A。

然后在B中创建一个接口，并将数据传递给Main Activity。在那里创建另一个接口并将数据传递给片段 A。

分享一个小例子：

片段 A 的样子

public class FragmentA extends Fragment implements InterfaceDataCommunicatorFromActivity {
    public InterfaceDataCommunicatorFromActivity interfaceDataCommunicatorFromActivity;
    String data;

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

    @Override
    public void updateData(String data) {
        this.data = data;
        //data is updated here which is from fragment B
    }

    @Override
    public void onAttach(Activity activity) {
    super.onAttach(activity);
        try {
            interfaceDataCommunicatorFromActivity = (InterfaceDataCommunicatorFromActivity) activity;
        } catch (ClassCastException e) {
            throw new ClassCastException(activity.toString()
                    + " must implement InterfaceDataCommunicatorFromActivity");
        }
    }

}

FragmentB 看起来像

class FragmentB extends Fragment {
    public InterfaceDataCommunicator interfaceDataCommunicator;

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

        // call this inorder to send Data to interface
        interfaceDataCommunicator.updateData("data");
    }

    public interface InterfaceDataCommunicator {
        public void updateData(String data);
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        try {
            interfaceDataCommunicator = (InterfaceDataCommunicator) activity;
        } catch (ClassCastException e) {
            throw new ClassCastException(activity.toString()
                    + " must implement InterfaceDataCommunicator");
        }
    }

}

主要活动是

public class MainActivity extends Activity implements InterfaceDataCommunicator {
    public InterfaceDataCommunicatorFromActivity interfaceDataCommunicatorFromActivity;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public void updateData(String data) {
        interfaceDataCommunicatorFromActivity.updateData(data);
    }

    public interface InterfaceDataCommunicatorFromActivity {
        public void updateData(String data);
    }

}

Answer 2

最简单的方法是在第一个片段中创建一个静态变量并在第二个片段中使用这个变量。

Answer 3

使用公共接口通过包含片段的 Activity 传递字符串。 Here 是更详细的类似问题和解决方案。

Answer 4

考虑 2 个片段 A 和 B，假设我需要将数据从 B 传递到 A。

然后在B中创建一个接口，并将数据传递给Activity。从那里您可以拨打 A getActivity() 以获取信息。

例子：

活动是：

public class MainActivity extends Activity implements InterfaceDataCommunicator {
    public static String data;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public void updateData(String data) {
        this.data = data;
    }

}

片段 A：

public class FragmentA extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        getActivity().data;//receive data

        return super.onCreateView(inflater, container, savedInstanceState);
    }

}

片段 B：

class FragmentB extends Fragment {
    public InterfaceDataCommunicator interfaceDataCommunicator;

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

        interfaceDataCommunicator.updateData(/*the String to send*/); //send data
    }

    public interface InterfaceDataCommunicator {
        public void updateData(String data);
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        try {
            interfaceDataCommunicator = (InterfaceDataCommunicator) activity;
        } catch (ClassCastException e) {
            throw new ClassCastException(activity.toString()
                    + " must implement InterfaceDataCommunicator");
        }
    }

}