Android 首次进入应用时加载引导界面

功能需求：首次进入应用时加载引导界面

思路：

1、首次进入，怎么判断？查看SharedPreferences中某个字段

2、基本上每个应用都有个进入实际功能是的动画加载页面，我们可以在该Activity中加入判断，看是否需要跳转到引导Activity

3、引导界面，采用现在比较主流的方式：左右滑动加载；小圆点提示；在最后一个页面，点击button，进入功能界面

实现功能：左右手势滑屏

底部小圆点随当前显示页跳动

浮动按钮显示。当触屏事件发生显示，否则就渐渐消失

　　第一种： ViewFlipper + GestureDetector

　　第二种： ActivityGroup +   GestureDetector

　　第三种： ViewPager  (Android3.0+)

　　第四种： ViewFlow (开源项目)

当你需要在一系列不确定数目的view中滑动时，可以考虑使用ViewFlow。如果你的view数目确定，你应该使用Fragments 或兼容库里的ViewPager 。

综合考虑代码复杂度以及以及加载的引导view个数可确定性，我们就采用第三种方案ViewPager。

（1）修改应用的动画加载页面SplashActivity.java

package com.example.guidepagetest2;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;

/**
 * 功能：使用ViewPager实现初次进入应用时的引导页
 *
 * (1)判断是否是首次加载应用--采取读取SharedPreferences的方法
 * (2)是，则进入引导activity；否，则进入MainActivity
 * (3)5s后执行(2)操作
 *
 * @author sz082093
 *
 */
public class SplashActivity extends Activity {

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

        boolean mFirst = isFirstEnter(SplashActivity.this,SplashActivity.this.getClass().getName());
        if(mFirst)
            mHandler.sendEmptyMessageDelayed(SWITCH_GUIDACTIVITY,5000);
        else
            mHandler.sendEmptyMessageDelayed(SWITCH_MAINACTIVITY,5000);
    }   

    //****************************************************************
    // 判断应用是否初次加载，读取SharedPreferences中的guide_activity字段
    //****************************************************************
    private static final String SHAREDPREFERENCES_NAME = "my_pref";
    private static final String KEY_GUIDE_ACTIVITY = "guide_activity";
    private boolean isFirstEnter(Context context,String className){
        if(context==null || className==null||"".equalsIgnoreCase(className))return false;
        String mResultStr = context.getSharedPreferences(SHAREDPREFERENCES_NAME, Context.MODE_WORLD_READABLE)
                 .getString(KEY_GUIDE_ACTIVITY, "");//取得所有类名 如 com.my.MainActivity
        if(mResultStr.equalsIgnoreCase("false"))
            return false;
        else
            return true;
    }

    //*************************************************
    // Handler:跳转至不同页面
    //*************************************************
    private final static int SWITCH_MAINACTIVITY = 1000;
    private final static int SWITCH_GUIDACTIVITY = 1001;
    public Handler mHandler = new Handler(){
        public void handleMessage(Message msg) {
            switch(msg.what){
            case SWITCH_MAINACTIVITY:
                Intent mIntent = new Intent();
                mIntent.setClass(SplashActivity.this, MainActivity.class);
                SplashActivity.this.startActivity(mIntent);
                SplashActivity.this.finish();
                break;
            case SWITCH_GUIDACTIVITY:
                mIntent = new Intent();
                mIntent.setClass(SplashActivity.this, GuideActivity.class);
                SplashActivity.this.startActivity(mIntent);
                SplashActivity.this.finish();
                break;
            }
            super.handleMessage(msg);
        }
    };

(2)添加引导Activity的布局文件activity_guide.xml

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

    <LinearLayout
        android:id="@+id/linearLayout1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <android.support.v4.view.ViewPager
            android:id="@+id/guidePages"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"/>
    </LinearLayout>

    <LinearLayout
        android:id="@+id/linearLayout2"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <RelativeLayout
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">

            <LinearLayout
                android:id="@+id/viewGroup"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:layout_alignParentBottom="true"
                android:layout_marginBottom="40dp"
                android:gravity="center_horizontal"
                android:orientation="horizontal">

            </LinearLayout>
        </RelativeLayout>

    </LinearLayout>

</FrameLayout>

(3)添加引导时，左右滑动时的view，这里示例两个：

viewpager_page1.xml

<?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:orientation="vertical">

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_gravity="center"
        android:text="@string/guide_begin"
        />

</LinearLayout>

viewpager_page2.xml

<?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:orientation="vertical"
    android:gravity="center">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/guide_end"/>
    <Button
        android:id="@+id/btn_close_guide"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/btn_close_guide"/>

 </LinearLayout>

(4)修改引导Activity：GuideActivity.java

package com.example.guidepagetest2;

import java.util.ArrayList;

import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.os.Parcelable;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.widget.Button;
import android.widget.ImageView;

public class GuideActivity extends Activity {
    private ViewPager viewPager;

    /**装分页显示的view的数组*/
    private ArrayList<View> pageViews;
    private ImageView imageView;

    /**将小圆点的图片用数组表示*/
    private ImageView[] imageViews;

    //包裹滑动图片的LinearLayout
    private ViewGroup viewPics;

    //包裹小圆点的LinearLayout
    private ViewGroup viewPoints;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        //将要分页显示的View装入数组中
        LayoutInflater inflater = getLayoutInflater();
        pageViews = new ArrayList<View>();
        pageViews.add(inflater.inflate(R.layout.viewpager_page1, null));
        pageViews.add(inflater.inflate(R.layout.viewpager_page2, null));

        //创建imageviews数组，大小是要显示的图片的数量
        imageViews = new ImageView[pageViews.size()];
        //从指定的XML文件加载视图
        viewPics = (ViewGroup) inflater.inflate(R.layout.activity_guide, null);

        //实例化小圆点的linearLayout和viewpager
        viewPoints = (ViewGroup) viewPics.findViewById(R.id.viewGroup);
        viewPager = (ViewPager) viewPics.findViewById(R.id.guidePages);

        //添加小圆点的图片
        for(int i=0;i<pageViews.size();i++){
            imageView = new ImageView(GuideActivity.this);
            //设置小圆点imageview的参数
            imageView.setLayoutParams(new LayoutParams(20,20));//创建一个宽高均为20 的布局
            imageView.setPadding(20, 0, 20, 0);
            //将小圆点layout添加到数组中
            imageViews[i] = imageView;

            //默认选中的是第一张图片，此时第一个小圆点是选中状态，其他不是
            if(i==0){
                imageViews[i].setBackgroundResource(R.drawable.page_indicator_focused);
            }else{
                imageViews[i].setBackgroundResource(R.drawable.page_indicator);
            }

            //将imageviews添加到小圆点视图组
            viewPoints.addView(imageViews[i]);
        }

        //显示滑动图片的视图
        setContentView(viewPics);

        //设置viewpager的适配器和监听事件
        viewPager.setAdapter(new GuidePageAdapter());
        viewPager.setOnPageChangeListener(new GuidePageChangeListener());
    }

    private Button.OnClickListener  Button_OnClickListener = new Button.OnClickListener() {
        public void onClick(View v) {
            //设置已经引导
            setGuided();

            //跳转
            Intent mIntent = new Intent();
            mIntent.setClass(GuideActivity.this, MainActivity.class);
            GuideActivity.this.startActivity(mIntent);
            GuideActivity.this.finish();
        }
    }; 

    private static final String SHAREDPREFERENCES_NAME = "my_pref";
    private static final String KEY_GUIDE_ACTIVITY = "guide_activity";
    private void setGuided(){
        SharedPreferences settings = getSharedPreferences(SHAREDPREFERENCES_NAME, 0);
        SharedPreferences.Editor editor = settings.edit();
        editor.putString(KEY_GUIDE_ACTIVITY, "false");
        editor.commit();
    }

    class GuidePageAdapter extends PagerAdapter{

        //销毁position位置的界面
        @Override
        public void destroyItem(View v, int position, Object arg2) {
            // TODO Auto-generated method stub
            ((ViewPager)v).removeView(pageViews.get(position));

        }

        @Override
        public void finishUpdate(View arg0) {
            // TODO Auto-generated method stub

        }

        //获取当前窗体界面数
        @Override
        public int getCount() {
            // TODO Auto-generated method stub
            return pageViews.size();
        }

        //初始化position位置的界面
        @Override
        public Object instantiateItem(View v, int position) {
            // TODO Auto-generated method stub
            ((ViewPager) v).addView(pageViews.get(position));  

             // 测试页卡1内的按钮事件
            if (position == 1) {
                Button btn = (Button) v.findViewById(R.id.btn_close_guide);
                btn.setOnClickListener(Button_OnClickListener);
            }  

            return pageViews.get(position);
        }

        // 判断是否由对象生成界面
        @Override
        public boolean isViewFromObject(View v, Object arg1) {
            // TODO Auto-generated method stub
            return v == arg1;
        }

        @Override
        public void startUpdate(View arg0) {
            // TODO Auto-generated method stub

        }

        @Override
        public int getItemPosition(Object object) {
            // TODO Auto-generated method stub
            return super.getItemPosition(object);
        }

        @Override
        public void restoreState(Parcelable arg0, ClassLoader arg1) {
            // TODO Auto-generated method stub

        }

        @Override
        public Parcelable saveState() {
            // TODO Auto-generated method stub
            return null;
        }
    }

    class GuidePageChangeListener implements OnPageChangeListener{

        @Override
        public void onPageScrollStateChanged(int arg0) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onPageScrolled(int arg0, float arg1, int arg2) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onPageSelected(int position) {
            // TODO Auto-generated method stub
            for(int i=0;i<imageViews.length;i++){
                imageViews[position].setBackgroundResource(R.drawable.page_indicator_focused);
                //不是当前选中的page，其小圆点设置为未选中的状态
                if(position !=i){
                    imageViews[i].setBackgroundResource(R.drawable.page_indicator);
                }
            }

        }
    }
 }

动画加载页面：

引导页面：

点击“关闭引导界面”或者非首次进入应用后的功能页面：