ViewPager Entry 1: ViewPager entry

ViewPager Entry 1: ViewPager entry

You can use ViewPager to switch between different views.

For example, the sliding between the four views is realized.

1. Create a project and introduce the ViewPager control ViewPager. It is a class that comes with an additional package in the google SDk and can be used to switch between screens.

<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"    tools:context="com.skyfin.viewpage.MainActivity" ><android.support.v4.view.ViewPager    android:id="@+id/pager"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    ></android.support.v4.view.ViewPager></LinearLayout>

2. Create four new LinearLayout views for slide Switching

<?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:background="@color/antiquewhite"    android:gravity="center"    android:orientation="vertical" >    <TextView         android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="tab2"        android:textSize="20dp"        android:textColor="@color/black"        /></LinearLayout>

3. Load the view into Viewpager.

Import android. r. id; import android. app. activity; import android. OS. bundle; import android. support. v4.view. pagerAdapter; import android. support. v4.view. pagerTabStrip; import android. support. v4.view. viewPager; import android. support. v4.view. viewPager. onPageChangeListener; import android. util. log; import android. view. layoutInflater; import android. view. menu; import android. view. menuItem; import android. view. view; import android. view. viewGroup; public class MainActivity extends Activity {ViewPager = null; public String TAG = "tag"; ArrayList <View> viewContainter = new ArrayList <View> (); arrayList <String> titleContainer = new ArrayList <String> (); @ SuppressWarnings ("deprecation") @ Overrideprotected void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState); setContentView (R. layout. activity_main); ViewPager = (ViewPager) findViewById (R. id. pager); View view1 = LayoutInflater. from (this ). inflate (R. layout. tab1, null); View view2 = LayoutInflater. from (this ). inflate (R. layout. tab2, null); View view3 = LayoutInflater. from (this ). inflate (R. layout. tab3, null); View view4 = LayoutInflater. from (this ). inflate (R. layout. tab4, null); // viewpager starts to add viewContainter. add (view1); viewContainter. add (view2); viewContainter. add (view3); viewContainter. add (view4); ViewPager. setAdapter (new PagerAdapter () {// number of components in viewpager @ Override public int getCount () {return viewContainter. size () ;}// destroy the current component @ Override public void destroyItem (ViewGroup container, int position, Object object) {(ViewPager) container) during sliding switching ). removeView (viewContainter. get (position);} // component generated during each slide @ Override public Object instantiateItem (ViewGroup container, int position) {(ViewPager) container ). addView (viewContainter. get (position); return viewContainter. get (position) ;}@ Override public boolean isViewFromObject (View arg0, Object arg1) {return arg0 = arg1 ;}@ Override public int getItemPosition (Object object) {return super. getItemPosition (object) ;}}); ViewPager. setOnPageChangeListener (new OnPageChangeListener () {@ Override public void onPageScrollStateChanged (int arg0) {}@ Override public void onPageScrolled (int arg0, float arg1, int arg2) {}@ Override public void onPageSelected (int arg0) {}}) ;}@ Overridepublic boolean onCreateOptionsMenu (Menu menu) {// Inflate the menu; this adds items to the action bar if it is present. getMenuInflater (). inflate (R. menu. main, menu); return true ;}@ Overridepublic boolean onOptionsItemSelected (MenuItem item) {// Handle action bar item clicks here. the action bar will // automatically handle clicks on the Home/Up button, so long // as you specify a parent activity in AndroidManifest.xml.int id = item. getItemId (); if (id = R. id. action_settings) {return true;} return super. onOptionsItemSelected (item );}}

Code Description 1. Define a ViewPager container

ViewPager ViewPager = null;ArrayList<View> viewContainter = new ArrayList<View>();

2. initialize and change the View and ViewPager and add them to the viewContainter container of the View.

View view1 = LayoutInflater. from (this ). inflate (R. layout. tab1, null); View view2 = LayoutInflater. from (this ). inflate (R. layout. tab2, null); View view3 = LayoutInflater. from (this ). inflate (R. layout. tab3, null); View view4 = LayoutInflater. from (this ). inflate (R. layout. tab4, null); // viewpager starts to add viewContainter. add (view1); viewContainter. add (view2); viewContainter. add (view3); viewContainter. add (view4 );

3. Add to PagerAdapter and set the listener

ViewPager. setAdapter (new PagerAdapter () {// number of components in viewpager @ Override public int getCount () {return viewContainter. size () ;}// destroy the current component @ Override public void destroyItem (ViewGroup container, int position, Object object) {(ViewPager) container) during sliding switching ). removeView (viewContainter. get (position);} // component generated during each slide @ Override public Object instantiateItem (ViewGroup container, int position) {(ViewPager) container ). addView (viewContainter. get (position); return viewContainter. get (position) ;}@ Override public boolean isViewFromObject (View arg0, Object arg1) {return arg0 = arg1 ;}@ Override public int getItemPosition (Object object) {return super. getItemPosition (object) ;}@ Override public CharSequence getPageTitle (int position) {return titleContainer. get (position) ;}}); ViewPager. setOnPageChangeListener (new OnPageChangeListener () {@ Override public void onPageScrollStateChanged (int arg0) {}@ Override public void onPageScrolled (int arg0, float arg1, int arg2) {}@ Override public void onPageSelected (int arg0 ){}});

The following four functions must be rewritten by PageAdapter:

• Boolean isViewFromObject (View arg0, Object arg1)
• Int getCount ()
• Void destroyItem (ViewGroup container, int position, Object object Object)
• Object instantiateItem (ViewGroup container, int position)

Let's first look at each function. What have we done above:

[Java]View plaincopy

1. @ Override
2. Public int getCount (){
3. // TODO Auto-generated method stub
4. Return viewList. size ();
5. }

GetCount (): returns the number of views to slide.

[Java]View plaincopy

1. @ Override
2. Public void destroyItem (ViewGroup container, int position,
3. Object object ){
4. // TODO Auto-generated method stub
5. Container. removeView (viewList. get (position ));
6. }

DestroyItem (): deletes the View at the specified position from the current container;
[Java]View plaincopy

1. @ Override
2. Public Object instantiateItem (ViewGroup container, int position ){
3. // TODO Auto-generated method stub
4. Container. addView (viewList. get (position ));
7. Return viewList. get (position );
8. }
9. };

InstantiateItem (): do two things: first: add the current View to the container, and second: return the current View
[Java]View plaincopy

1. @ Override
2. Public boolean isViewFromObject (View arg0, Object arg1 ){
3. // TODO Auto-generated method stub
4. Return arg0 = arg1;
5. }

IsViewFromObject ()

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