Fragment间的通信

Fragment通信

主要说的是activity与fragment的数据传递、fragment与activity的数据传递和fragment与fragment之前的数据传递

一、activity与fragment之间的通信

采用 Bundle方式。具体Demo步骤如下：
   步骤1：Activity的布局文件act_to_fragment.xml
   步骤2：设置 Fragment的布局文件fragment_com.xml
   步骤3：设置Activity的类文件ActToFragment.java
   步骤4：设置Fragment的类文件fragment_com.java

1.activity页面文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".ActToFragment"
    android:orientation="vertical">

    <TextView
        android:id="@+id/text"
        android:layout_gravity="center"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="20dp"
        android:text="我是Activity" />

    <FrameLayout
        android:layout_below="@+id/button"
        android:id="@+id/fragment_container"
        android:layout_width="match_parent"
        android:layout_height="500dp"/>

</LinearLayout>

　2.设置 Fragment的布局文件

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/colorAccent"
    >

    <TextView
        android:id="@+id/com_vfa"
        android:text="我是fragment"
        android:layout_gravity="center"
        android:textSize="30dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        />

    <TextView
        android:id="@+id/text"
        android:layout_gravity="center"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="20dp"
        android:text="等待Activity发送消息" />

    <Button
        android:id="@+id/button"
        android:layout_gravity="center"
        android:text="点击接收Activity消息"
        android:layout_centerInParent="true"
        android:textSize="20dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
</LinearLayout>

　3.设置activity的类文件

public class ActToFragment extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.act_to_fragment);
        FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
        //创建需要添加的fragment;
        FragmentCom fragmentCom = new FragmentCom();
        //创建bundle对象并将数据传递到fragment中去
        Bundle bundle = new Bundle();
        bundle.putString("message", "I love Google");
        fragmentCom.setArguments(bundle);
        transaction.add(R.id.fragment_container,fragmentCom);
        transaction.commit();
    }
}

4.　fragment的类文件

 @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_com, container, false);

        TextView textView = (TextView) view.findViewById(R.id.text);

        Button button = (Button) view.findViewById(R.id.button);

        //通过getArguments获取bundle对象
        Bundle bundle = this.getArguments();

        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                textView.setText(bundle.getString("message"));
            }
        });
        return view;
    }

二、fragment与activity的通信

fragment传递消息到activity
 1、定义接口
 2、实现接口
 3、消息传递
1.设置activity布局文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".FragmentToActActivity"
    android:orientation="vertical"
    >

    <TextView
        android:id="@+id/text_second"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="20dp"
        android:text="等待Fragment发送消息" />

    <Button
        android:id="@+id/button_second"
        android:layout_below="@+id/text"
        android:text="点击接收Fragment消息"
        android:layout_centerInParent="true"
        android:textSize="10dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <FrameLayout
        android:layout_below="@+id/selected"
        android:id="@+id/fragment_container"
        android:layout_width="match_parent"
        android:layout_height="500dp"/>

</LinearLayout>

　　2.设置Fragment的布局文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >

    <TextView
        android:id="@+id/fragment"
        android:text="我是fragment"
        android:gravity="center"
        android:textSize="30dp"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@color/colorAccent"/>
</LinearLayout>

　　3.设置回调接口：ICallBack.java

public interface ICallBack {

    void getMessageFromFragment(String message);
}

　　4.设置fragment的类文件

 @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_com_sencond, container, false);
    }


    //实现定义的接口

    public void sendMessage(ICallBack iCallBack){
        iCallBack.getMessageFromFragment("我是来自fragment的消息");
    }

　　5.设置activity的类文件

public class FragmentToActActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_fragment_to_act);
        TextView textView = (TextView) findViewById(R.id.text_second);

        Button button = (Button) findViewById(R.id.button_second);

        FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();

        ComSencondFragment comSencondFragment = new ComSencondFragment();

        transaction.add(R.id.fragment_container, comSencondFragment).commit();

        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                comSencondFragment.sendMessage(new ICallBack() {
                    @Override
                    public void getMessageFromFragment(String message) {
                        textView.setText(message);
                    }
                });
            }
        });
    }
}