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文章目录
  1. 1. 简单介绍
  2. 2. 实例

简单介绍

一个完整的Android应用一般都会有进入应用时的欢迎页，首次使用的导航页。本篇介绍使用ViewPager实现该功能的方法。

实例

首先建立三个导航页面xml，然后建立一个管理导航页面的xml，我的如下:

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

    <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:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:gravity="center_horizontal"
        android:orientation="horizontal">

        <ImageView
            android:id="@+id/iv_point1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@mipmap/guide_point_selected" />

        <ImageView
            android:id="@+id/iv_point2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@mipmap/guide_point" />

        <ImageView
            android:id="@+id/iv_point3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@mipmap/guide_point" />
    </LinearLayout>

</RelativeLayout>

然后欢迎页的类WelcomeActivity

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package com.carlos.guide;

import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

public class WelcomeActivity extends AppCompatActivity {

    private boolean isFirstIn=false;
    private static final int TIME=2*1000;//延迟两秒
    private static final int GO_HOME=0;
    private static final int GO_GUIDE=1;
    

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

        //初始化控件
        initView();
    }

    private void initView(){
        SharedPreferences preferences=getSharedPreferences("guide",MODE_PRIVATE);
        isFirstIn=preferences.getBoolean("isFirstIn",true);
        if(isFirstIn){//如果第一次进入就显示导航页，第二次以后就不用显示
            handler.sendEmptyMessageDelayed(GO_GUIDE,TIME);
        }else{
            handler.sendEmptyMessageDelayed(GO_HOME,TIME);
            SharedPreferences.Editor editor=preferences.edit();
            editor.putBoolean("isFirstIn",false);
            editor.commit();
        }
    }

    /**
     * 进入引导页面
     */
    private void goGuide(){
        Intent intent=new Intent(WelcomeActivity.this,GuideActivity.class);
        startActivity(intent);
        finish();
    }

    /**
     * 进入主界面
     */
    private void goHome(){
        Intent intent =new Intent(WelcomeActivity.this,HomeActivity.class);
        startActivity(intent);
        finish();
    }

    Handler handler=new Handler(){
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            switch (msg.what){
                case GO_GUIDE:
                    goGuide();
                    break;
                case GO_HOME:
                    goHome();
                    break;
            }
        }
    };

}

新建的ViewPagerAdapter适配器

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package com.carlos.guide;

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 xiaobudian on 2015/12/8.
 */
public class ViewPagerAdapter extends PagerAdapter{

    //界面列表
    private List<View> views;
    private Context context;

    public ViewPagerAdapter(List<View> views,Context context){
        this.views=views;
        this.context=context;
    }

    //销毁position位置的界面
    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
        ((ViewPager)container).removeView(views.get(position));
    }

    //初始化position位置的界面
    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        ((ViewPager)container).addView(views.get(position));
        return views.get(position);
    }

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

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

新建引导页的类GuideActivity

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package com.carlos.guide;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

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

/**
 * Created by xiaobudian on 2015/12/7.
 */
public class GuideActivity extends Activity implements ViewPager.OnPageChangeListener{

    private ViewPager viewPager;
    private ViewPagerAdapter viewPagerAdapter;
    private List<View> views;
    private ImageView[] dots;
    private int[] ids={R.id.iv_point1,R.id.iv_point2,R.id.iv_point3};
    private Button b_enter;


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

        //初始化界面
        initViews();
        //初始化小圆点
        initDots();
    }

    public void initViews(){
        LayoutInflater layoutInflater=LayoutInflater.from(this);
        views=new ArrayList<>();
        views.add(layoutInflater.inflate(R.layout.guide_one,null));
        views.add(layoutInflater.inflate(R.layout.guide_two,null));
        views.add(layoutInflater.inflate(R.layout.guide_three,null));
        viewPagerAdapter=new ViewPagerAdapter(views,this);
        viewPager= (ViewPager) findViewById(R.id.viewpager);
        viewPager.setAdapter(viewPagerAdapter);
        b_enter= (Button) views.get(2).findViewById(R.id.b_enter);
        b_enter.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(GuideActivity.this, HomeActivity.class);
                startActivity(intent);
                finish();
            }
        });
        viewPager.setOnPageChangeListener(this);
    }

    public void initDots(){
        dots=new ImageView[views.size()];
        for(int i=0;i<views.size();i++){
            dots[i]=(ImageView)findViewById(ids[i]);
        }
    }

    @Override
    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

    }

    @Override
    public void onPageSelected(int position) {
        for(int i=0;i<ids.length;i++){
            if(position==i){
                dots[i].setImageResource(R.mipmap.guide_point_selected);
            }else{
                dots[i].setImageResource(R.mipmap.guide_point);
            }
        }
    }

    @Override
    public void onPageScrollStateChanged(int state) {

    }
}

最后自己写主界面的实现功能。运行即可以看到首次打开时出现欢迎页面，延迟两秒后到导航页面，三个导航页面滑动后点击进入即到了主界面。以后再进入时就直接从欢迎页面到主界面。

文章目录
  1. 1. 简单介绍
  2. 2. 实例