Android ViewPage的使用（一）

ViewPage是一个简单的页面切换组件，左右滑动的话，有效果，和ListView一样

也需要配合适配器（PagerAdapter）来使用。

先来个效果图吧

先随便创建3个view页面，用于放到 ViewPage里面

view_one.xml

view_two.xml  和上面页面内容一样，

view_there.xml  和上面页面内容一样，

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

    <TextView
        android:id="@+id/textView"
        android:layout_width="140dp"
        android:layout_height="101dp"
        android:text="one"
        android:textSize="30sp" />
</android.support.constraint.ConstraintLayout>

主页面activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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"
    tools:context=".MainActivity">

    <android.support.v4.view.ViewPager
        android:id="@+id/vpager_one"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center">

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

</android.support.constraint.ConstraintLayout>

适配器：

package action.sun.com.viewpage1;

import android.support.v4.view.PagerAdapter;
import android.view.View;
import android.view.ViewGroup;

import java.util.ArrayList;

public class MyPagerAdapter extends PagerAdapter {

    private ArrayList<View> viewLists;

    public MyPagerAdapter() {
    }

    public MyPagerAdapter(ArrayList<View> viewLists) {
        super();
        this.viewLists = viewLists;
    }

    @Override
    public int getCount() {
        return viewLists.size();
    }

    @Override
    public boolean isViewFromObject(View view, Object object) {
        return view == object;
    }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        container.addView(viewLists.get(position));
        return viewLists.get(position);
    }

    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
        container.removeView(viewLists.get(position));
    }
}

主页面调用代码：

package action.sun.com.viewpage1;

import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    private ViewPager vpager;
    private ArrayList<View> aList;
    private MyPagerAdapter mAdapter;

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

        vpager = (ViewPager) findViewById(R.id.vpager_one);

        aList = new ArrayList<View>();
        LayoutInflater li = getLayoutInflater();
        aList.add(li.inflate(R.layout.view_one,null,false));
        aList.add(li.inflate(R.layout.view_two,null,false));
        aList.add(li.inflate(R.layout.view_there,null,false));
        mAdapter = new MyPagerAdapter(aList);
        vpager.setAdapter(mAdapter);
    }
}

以上，基本的ViewPage就能够实现了。