ViewPager和Fragments：为什么我总是看到相同的东西？

Question

I have created a ViewPager with three "pages". The code is this

MainActivity.java

public class MainActivity extends FragmentActivity {

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


        ViewPager viewPager = (ViewPager) findViewById(R.id.pager);
        PagerTabStrip pagerTabStrip = (PagerTabStrip) findViewById(R.id.pager_tab_strip);
        FragmentPagerAdapter fragmentPagerAdapter = new MyFragmentPagerAdapter(
                getSupportFragmentManager());

        viewPager.setAdapter(fragmentPagerAdapter);
        pagerTabStrip.setDrawFullUnderline(true);
        pagerTabStrip.setTabIndicatorColor(Color.DKGRAY);
    }

}

MyFragmentPageAdapter.java

public class MyFragmentPagerAdapter extends FragmentPagerAdapter {

    private String[] pageTitle = {
            "Page1", "Page2", "Page3"
    };

    public MyFragmentPagerAdapter(FragmentManager fragmentManager) {
        super(fragmentManager);
    }

    @Override
    public Fragment getItem(int position) {
        Fragment fragment = new PageFragment();
        Bundle arguments = new Bundle();
        arguments.putString("pageIndex", Integer.toString(position + 1));
        fragment.setArguments(arguments);
        return fragment;
    }

    @Override
    public int getCount() {
        return pageTitle.length;
    }

    @Override
    public CharSequence getPageTitle(int position) {
        return pageTitle[position];
    }

}

PageFragment.java

public class PageFragment extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = getActivity().getLayoutInflater().inflate(R.layout.fragment_page, null);

    return view;

    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/RelativeLayout1"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >

<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/pager"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >
    <android.support.v4.view.PagerTabStrip
        android:id="@+id/pager_tab_strip"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="top"
        android:background="#33B5E5"
        android:textColor="#FFFFFF"
        android:paddingTop="10dp"
        android:paddingBottom="10dp" />

    </android.support.v4.view.ViewPager>

</RelativeLayout>

fragment_page.xml

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

    <TextView
        android:id="@+id/textView1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="20dp"
        android:textSize="16sp"
        android:textStyle="italic"
        android:gravity="center_horizontal"
        android:textColor="@color/red"
        android:text="@string/inf" />

        <TextView
        android:id="@+id/textView2"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="60dp"
        android:textSize="28sp"
        android:gravity="center_horizontal"
        android:textStyle="bold"
        android:text="@string/ben" />

                <TextView
        android:id="@+id/textView3"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="130dp"
        android:gravity="center_horizontal"
        android:textSize="18sp"
        android:text="Prova"
         />

        <Button
            android:id="@+id/button1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical|center_horizontal"
            android:layout_centerInParent="true"
            android:text="@string/verifica" />

</RelativeLayout>

But now i visualize in all three pages the same thing. If I for example on page 2 I want a TextView with the text "This is the 2 page" and on the third page a TextView with the text "This is the page 3" and in the first page two TextView with the button ... how can I? I'm going crazy, please let pass me the code to do this thing. Please.

Answer 1

Once you inflate PageFragment 's layout you need to get a reference of the TextView so you can display the position on it via the Bundle you are passing using setArguments() . Use your view variable inside onCreateView() to get a reference of the TextView . (ie view.findViewById() ). Then use getArguments() in your PageFragment to retrieve the Bundle with that has position, and set the TextView to that value.

Answer 2

这是您想要的一个很好的例子。

Answer 3

Just create a function in your page fragment class to configure elements and modify onCreateView to attach childs.

public class PageFragment extends Fragment {

        TextView tv1 ;
        // ...

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            View view = getActivity().getLayoutInflater().inflate(R.layout.fragment_page, null);
            /// Attach your childs
            tv1 = view.findViewById(R.id.textView1);

        return view;

        }

        public void configure(int position) {
            tv1 .setText("This is "+ position);
        }
    }

Then just call the function configure in getItem function

  @Override
        public Fragment getItem(int position) {
            PageFragment fr = new PageFragment();
            fr.configure(position + 1);         
            return fr;
        }