在MainActivity内调用Fragment内的控件并实现方法

在MainActivity内调用Fragment内的控件，
并在MainActivity内实现Fragment内的控件的方法

MainActivety.java

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    private FragmentManager fragmentManager;
    private FragmentTransaction fragmentTransaction;
    private xxx x;
    private vvv v;
    private EditText xet ,vet;
    private Button xbt, vbt;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        fragmentManager = getFragmentManager();
        fragmentTransaction = fragmentManager.beginTransaction();
        x = new xxx();
        v = new vvv();
        fragmentTransaction.add(R.id.vvv, v, "fv");
        fragmentTransaction.add(R.id.xxx, x, "fx");
        fragmentTransaction.commit();
    }

    @Override
    protected void onStart() {
        super.onStart();
        xbt = (Button) x.getView().findViewById(R.id.xxxbutton);
        vbt = (Button) v.getView().findViewById(R.id.vvvbutton);
        xbt.setOnClickListener(this);
        vbt.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        vet = (EditText) v.getView().findViewById(R.id.vvveditText);
        xet = (EditText) x.getView().findViewById(R.id.xxxeditText);

        switch(view.getId()){
            case R.id.vvvbutton:
                if(vet != null) {
                    vet.setText(xet.getText().toString());
                    System.out.println(vet);
                }
                break;

            case R.id.xxxbutton:
                if(xet != null) {
                    xet.setText(vet.getText().toString());
                    System.out.println(xet);
                }
                break;
            default:
                break;
        }
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:id="@+id/activity_main"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="horizontal"

    tools:context="com.example.java.m1020a.MainActivity">

    <LinearLayout

        android:layout_width="match_parent"

        android:layout_height="match_parent"

        android:layout_weight="1"

        android:id="@+id/xxx"

        android:orientation="vertical"

        ></LinearLayout>

    <LinearLayout

        android:layout_width="match_parent"

        android:layout_height="match_parent"

        android:layout_weight="1"

        android:id="@+id/vvv"

        android:orientation="vertical"

        ></LinearLayout>

</LinearLayout>

vvv.java

xxx.java

public class vvv extends Fragment {

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

    }

    @Nullable

    @Override

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

        View v = inflater.inflate(R.layout.fvvv, null);

        return v;

    }

    @Override

    public void onPause() {

        super.onPause();

    }

}

fvvv.xml

fxxx.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">

    <EditText

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:inputType="textPersonName"

        android:text="fv"

        android:ems="10"

        android:id="@+id/vvveditText" />

    <Button

        android:text="fvvv"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:id="@+id/vvvbutton" />

</LinearLayout>