Android应用开发中Fragment间通信的实现教程

// 用来存放fragment的Activtiy必须实现这个接口
  public interface OnHeadlineSelectedListener {
    public void onArticleSelected(int position);
  }

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

    // 这是为了保证Activity容器实现了用以回调的接口。如果没有，它会抛出一个异常。
    try {
      mCallback = (OnHeadlineSelectedListener) activity;
    } catch (ClassCastException e) {
      throw new ClassCastException(activity.toString()
          + " must implement OnHeadlineSelectedListener");
    }
  }

@Override
  public void onListItemClick(ListView l, View v, int position, long id) {
    // 发送时间给Activity宿主
    mCallback.onArticleSelected(position);
  }

public static class MainActivity extends Activity
    implements HeadlinesFragment.OnHeadlineSelectedListener{
  ...
  
  public void onArticleSelected(int position) {
    // 用户选择了HeadlinesFragment中的头标题后
    // 做一些业务操作
  }
}

public static class MainActivity extends Activity
    implements HeadlinesFragment.OnHeadlineSelectedListener{
  ...

  public void onArticleSelected(int position) {
    // 用户选中HeadlinesFragment中的头标题后
    // 做一些必要的业务操作

    ArticleFragment articleFrag = (ArticleFragment)
        getSupportFragmentManager().findFragmentById(R.id.article_fragment);

    if (articleFrag != null) {
      // 如果 article frag 不为空，那么我们在同时显示两个fragmnet的布局中...

      // 调用ArticleFragment中的方法去更新它的内容
      articleFrag.updateArticleView(position);
    } else {
      // 否则，我们就是在仅包含一个fragment的布局中并需要交换fragment...

      // 创建fragment并给他一个跟选中的文章有关的参数
      ArticleFragment newFragment = new ArticleFragment();
      Bundle args = new Bundle();
      args.putInt(ArticleFragment.ARG_POSITION, position);
      newFragment.setArguments(args);
    
      FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();

      // 用这个fragment替换任何在fragment_container中的东西
      // 并添加事务到back stack中以便用户可以回退到之前的状态
      transaction.replace(R.id.fragment_container, newFragment);
      transaction.addToBackStack(null);

      // 提交事务
      transaction.commit();
    }
  }
}

public class MainActivity extends Activity implements MyListener {
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    FragmentManager manager = getFragmentManager();
    FragmentTransaction fragmentTransaction = manager.beginTransaction();
    Fragment1 fragment1 = new Fragment1();
    fragmentTransaction.add(R.id.layout1, fragment1);
    fragmentTransaction.commit();

  }
    //在mainActivity中实现MyListener接口并实现它未实现的方法，在该方法中传递数据
  @Override
  public void send(String info) {
    Toast.makeText(this, "Activity成功接收" + info, 0).show();    
    Fragment2 fragment2 = new Fragment2();
    Bundle bundle = new Bundle();
    bundle.putString("name", info);
    fragment2.setArguments(bundle);
    FragmentManager manager = getFragmentManager();
    FragmentTransaction fragmentTransaction = manager.beginTransaction();
    //替换该Fragment        
    fragmentTransaction.replace(R.id.layout2, fragment2, "fragment2");

    fragmentTransaction.commit();
  }

}

 public class Fragment1 extends Fragment {
  EditText et;
  Button enter;
  private String info;
  @Override
  public void onAttach(Activity activity) {
    listener = (MyListener) activity;
    super.onAttach(activity);
  }
  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container,
      Bundle savedInstanceState) {

    View view = inflater.inflate(R.layout.fragment1_lay,container, false);
    et = (EditText) view.findViewById(R.id.et);
    enter = (Button) view.findViewById(R.id.enter);
    enter.setOnClickListener(new OnClickListener() {

      @Override
      public void onClick(View v) {
        info = et.getText().toString();
        listener.send(info);

      }
    });
    return view;
  }
  public MyListener listener;
    //定义一个接口
  public interface MyListener{ 
    public void send(String info);
  }

}
public class Fragment2 extends Fragment {

  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container,
      Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment2_lay,container, false);
    TextView tv = (TextView) view.findViewById(R.id.tv);
    tv.setText(getArguments().get("name")+"");//获取传递的值
    Toast.makeText(getActivity(), "fragment"+getArguments().get("name")+"", 0).show();
    return view;
  }

}

FragmentManager fragmentManager = getFragmentManager();
Fragment fragment = fragmentManager.findFragmentById(R.id.frag);//静态加载在Activity布局中设置的Fragment的ID
MyFragment frag = (MyFragment) fragment;
frag.setText1("fragment静态传值");

private String text1;
  public String getText1() {
    return text1;
  }
  public void setText1(String text1) {
    this.text1 = text1;
  }

     String value = getText1();