Fragment与Activity的通信

package com.zdsoft.activityfragment1205;import android.support.v4.app.Fragment;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;public class MainActivity extends AppCompatActivity implements ListFragment.OnItemSelectListener {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);    }    @Override    public void OnSelect(int index) {        String str = "";        //获得frament        ContentFragment fragment = (ContentFragment) getSupportFragmentManager().findFragmentById(R.id.f_content);        switch (index) {            case 0:                str = "你好，我是Android";                fragment.showMessage(str);                break;            case 1:                str = "你好，我是IOS";                fragment.showMessage(str);                break;            case 2:                str = "你好，我是WP";                fragment.showMessage(str);                break;            default:                break;        }    }}

package com.zdsoft.activityfragment1205;import android.content.Context;import android.os.Bundle;import android.support.v4.app.Fragment;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.AdapterView;import android.widget.ArrayAdapter;import android.widget.ListView;import android.widget.Toast;/** * A simple {@link Fragment} subclass. */public class ListFragment extends Fragment {    private ListView lv_show;    private String[] array = {"android", "IOS", "WP"};    OnItemSelectListener listener;    public ListFragment() {        // Required empty public constructor    }    @Override    public View onCreateView(LayoutInflater inflater, ViewGroup container,                             Bundle savedInstanceState) {        // Inflate the layout for this fragment        View view = inflater.inflate(R.layout.fragment_list, container, false);        ArrayAdapter<String> adapter = new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1, array);        lv_show = (ListView) view.findViewById(R.id.lv_show);        lv_show.setAdapter(adapter);        lv_show.setOnItemClickListener(new AdapterView.OnItemClickListener() {            @Override            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {                //调用接口内方法                listener.OnSelect(position);            }        });        return view;    }    /**     * 定义接口     */    public interface OnItemSelectListener {        public void OnSelect(int index);    }    /**     * 重写onAttach方法实例化listener;     *     * @param context     */    @Override    public void onAttach(Context context) {        super.onAttach(context);        listener = (OnItemSelectListener) context;    }}

package com.zdsoft.activityfragment1205;import android.os.Bundle;import android.support.v4.app.Fragment;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.TextView;/** * A simple {@link Fragment} subclass. */public class ContentFragment extends Fragment {    private TextView tv_show;    public ContentFragment() {        // Required empty public constructor    }    @Override    public View onCreateView(LayoutInflater inflater, ViewGroup container,                             Bundle savedInstanceState) {        // Inflate the layout for this fragment        View view = inflater.inflate(R.layout.fragment_content, container, false);        tv_show = (TextView) view.findViewById(R.id.tv_show);        return view;    }    public void showMessage(String msg) {        tv_show.setText(msg);    }}

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="horizontal">    <fragment        android:id="@+id/f_list"        android:name="com.zdsoft.activityfragment1205.ListFragment"        android:layout_width="0dp"        android:layout_height="match_parent"        android:layout_weight="1" />    <fragment        android:id="@+id/f_content"        android:name="com.zdsoft.activityfragment1205.ContentFragment"        android:layout_width="0dp"        android:layout_height="match_parent"        android:layout_weight="3" /></LinearLayout>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:background="@color/colorAccent"    android:orientation="vertical">    <!-- TODO: Update blank fragment layout -->    <ListView        android:id="@+id/lv_show"        android:layout_width="match_parent"        android:layout_height="match_parent" /></LinearLayout>

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context="com.zdsoft.activityfragment1205.ContentFragment">    <!-- TODO: Update blank fragment layout -->    <TextView        android:id="@+id/tv_show"        android:layout_width="match_parent"        android:layout_height="match_parent" /></FrameLayout>