ViewPager实现引导页

第一次安装app的时候总会跳出一些如何使用这个app的引导页，介绍这个app，本文主要讲解这个功能是如何实现的

场景：第一次启动app有引导页，以后启动直接进入主页面

使用Google提供的ViewPager

1.布局  一个ViewPager控件和底下的三个小黑点（随着页面的改动小黑点也会动）

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:showIn="@layout/activity_main"
    tools:context="com.example.myapplication.MainActivity">

 <android.support.v4.view.ViewPager
     android:id="@+id/viewpager"
     android:layout_width="match_parent"
     android:layout_height="match_parent">
 </android.support.v4.view.ViewPager>

 <LinearLayout
     android:id="@+id/dotsLayout"
     android:orientation="horizontal"
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"
     android:gravity="center_horizontal"
     android:layout_alignParentBottom="true">
 <ImageView
     android:src="@drawable/dot_sselect"
     android:id="@+id/dot1"
     android:layout_width="wrap_content"
     android:layout_height="wrap_content" />
  <ImageView
      android:src="@drawable/dot_unselect"
      android:id="@+id/dot2"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content" />
  <ImageView
      android:src="@drawable/dot_unselect"
      android:id="@+id/dot3"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content" />
 </LinearLayout>
</RelativeLayout>

2.设置设配器

package com.example.myapplication;

import android.content.Context;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.View;
import android.view.ViewGroup;

import java.util.List;

/**
 * Created by 小新 on 2016/3/13.
 */
public class MyViewPagerAdapter extends PagerAdapter {

    private List<View> views;
    public MyViewPagerAdapter( List<View> views){
        this.views = views;

    }

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

    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
        ((ViewPager)container).removeView(views.get(position));
    }
    @Override
    public int getCount() {
        return views.size();
    }

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

3.在avtivity中

package com.example.myapplication;

import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.LayoutInflater;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity implements ViewPager.OnPageChangeListener{

    private ViewPager viewPager;
    private  MyViewPagerAdapter myViewPagerAdapter;
    private List<View> views;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        viewPager = (ViewPager) findViewById(R.id.viewpager);
        views = new ArrayList<View>();
        //获取布局加载器
        LayoutInflater layoutInflater = LayoutInflater.from(this);
        //加载布局并且将布局添加到视图中去
        views.add( layoutInflater.inflate(R.layout.one,null));
        views.add(layoutInflater.inflate(R.layout.two,null));
        views.add(layoutInflater.inflate(R.layout.three,null));
        //创建设配器
        myViewPagerAdapter = new MyViewPagerAdapter(views);
        //绑定设配器
        viewPager.setAdapter(myViewPagerAdapter);


        setSupportActionBar(toolbar);

       FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });
    }
    //下面这三个方法是实现页面活动的监听器
    @Override
    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

    }

    @Override
    public void onPageSelected(int position) {

    }

    @Override
    public void onPageScrollStateChanged(int state) {

    }
}