ViewPager+Fragment簡單應用
利用ViewPager+Fragment實現多頁面
- 創建四個Fragment
在每個佈局中載入對應layout
其中的一個代碼,其他類似
public class IndexFragment extends Fragment {
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_index,container,false);
return view;
}
}
- 在activity_main.xml中添加ViewPager,四個TextView
<?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"
android:orientation="vertical"
tools:context=".MainActivity">
<androidx.viewpager.widget.ViewPager
android:id="@+id/vp_fragment"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="50dp"
android:background="#009688">
<TextView
android:id="@+id/tv_index"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:layout_gravity="center"
android:layout_marginLeft="30dp"
android:textSize="25sp"
android:text="首頁"/>
<TextView
android:id="@+id/tv_phone"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:layout_gravity="center"
android:textSize="25sp"
android:text="通訊錄"/>
<TextView
android:id="@+id/tv_disc"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:layout_gravity="center"
android:textSize="25sp"
android:text="發現"/>
<TextView
android:id="@+id/tv_me"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:layout_gravity="center"
android:textSize="25sp"
android:text="我"/>
</LinearLayout>
</LinearLayout>
- 創建FragmentAdapter類,繼承FragmentPagerAdapter
原理跟ListView類似
public class FragmentAdapter extends FragmentPagerAdapter {
private List<Fragment> list;
public FragmentAdapter(FragmentManager fm, List<Fragment> list) {
super(fm);
this.list = list;
}
@Override
public Fragment getItem(int position) {
return list.get(position);
}
@Override
public int getCount() {
return list.size();
}
}
- 在MainActivity中實現
public class MainActivity extends AppCompatActivity {
private ViewPager viewPager;
private FragmentAdapter adapter;
private List<Fragment> list;
private TextView tvIndex;
private TextView tvPhone;
private TextView tvDisc;
private TextView tvMe;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
viewPager = findViewById(R.id.vp_fragment);
tvIndex = findViewById(R.id.tv_index);
tvPhone = findViewById(R.id.tv_phone);
tvDisc = findViewById(R.id.tv_disc);
tvMe = findViewById(R.id.tv_me);
list = new ArrayList<>();
list.add(new IndexFragment());list.add(new PhoneFragment());
list.add(new DiscFragment());list.add(new MeFragment());
adapter = new FragmentAdapter(getSupportFragmentManager(), list);
viewPager.setAdapter(adapter);
viewPager.setCurrentItem(0);
viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
switch (position) {
case 0:
tvIndex.setTextColor(Color.RED);
tvPhone.setTextColor(Color.WHITE);
tvDisc.setTextColor(Color.WHITE);
tvMe.setTextColor(Color.WHITE);
break;
case 1:
tvPhone.setTextColor(Color.RED);
tvIndex.setTextColor(Color.WHITE);
tvDisc.setTextColor(Color.WHITE);
tvMe.setTextColor(Color.WHITE);
break;
case 2:
tvDisc.setTextColor(Color.RED);
tvIndex.setTextColor(Color.WHITE);
tvPhone.setTextColor(Color.WHITE);
tvMe.setTextColor(Color.WHITE);
break;
case 3:
tvMe.setTextColor(Color.RED);
tvIndex.setTextColor(Color.WHITE);
tvPhone.setTextColor(Color.WHITE);
tvDisc.setTextColor(Color.WHITE);
break;
default:
break;
}
}
@Override
public void onPageSelected(int position) {
}
@Override
public void onPageScrollStateChanged(int state) {
}
});
}
}
完成