【安卓学习笔记】Activity与Fragment通信——Activity发送到Fragment

要点：

• activity中，实例化fragment，并通过fragment的setArguments方法，向fragment发送bundle绑定的数据；

• fragment中，通过getArguments方法接收activity发送过来的数据。

具体代码：

1、MainActivity的布局文件activity_main.xml

<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:orientation="vertical"
    android:id="@+id/layout"    
    tools:context=".MainActivity" >
    
    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:inputType="text"
        android:id="@+id/et1" />
    <Button 
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="发送到fragment"
        android:id="@+id/btn"/>    
        
</LinearLayout>

2、MainActivity

public class MainActivity extends Activity {

    private EditText et01;
    private Button btn01;

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

        et01 = (EditText) findViewById(R.id.et1);
        btn01 = (Button) findViewById(R.id.btn);

        btn01.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {

                // 实例化自定义的fragment
                myFragment fragment = new myFragment();
                // 通过bundle绑定数据，fragment的setArguments方法传值
                Bundle bundle = new Bundle();
                bundle.putString("tag", et01.getText().toString());
                fragment.setArguments(bundle);

                // 后面和动态加载fragment一样
                FragmentManager fragmentManager = getFragmentManager();
                FragmentTransaction beginTransaction = fragmentManager
                        .beginTransaction();
                // 将fragment添加到activity的布局中
                beginTransaction.add(R.id.layout, fragment);
                beginTransaction.addToBackStack(null);
                beginTransaction.commit();
            }
        });
    }
}

3、fragment布局文件fragment.xml

<?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="vertical" >

    <TextView
        android:id="@+id/text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

4、自定义的Fragment

public class myFragment extends Fragment {

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

        View view = inflater.inflate(R.layout.fragment, container, false);
        TextView tv = (TextView) view.findViewById(R.id.text);

        // 获取activity发送来的数据
        Bundle bundle = getArguments();
        String value = bundle.getString("tag");
        tv.setText("接收到的值 为：" + value);
        return view;
    }
}