Android学习笔记之ViewPager的使用

 使用ViewPager这个类可以轻松实现多个页面的滑动功能,而且相对viewgroup来讲要简单容易一些,在此之前我们需要导入 android-support-v4.jar这个jar包,是google提供的扩展包,位置路径为 android-sdk-windows\extras\android\support\v4\ android-support-v4.jar,如果没有找到,需要打开Android SDK Manager在Extras中进行下载,最后记得引入工程中并build path。

在本示例中,我参考了几个demo整理出来的viewpager的最基本用法,制作了一个类似新闻导航功能的界面,每个页面的下方有对应的项目符号,当页面进行切换的时候项目符号也随之变化,下面是实现后的图片:

Android学习笔记之ViewPager的使用 Android学习笔记之ViewPager的使用 Android学习笔记之ViewPager的使用

 

java代码:

package com.cogent.viewpager;



import java.util.ArrayList;



import android.app.Activity;

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.view.Window;

import android.widget.ImageView;



public class ViewPagerGuideActivity 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);

        requestWindowFeature(Window.FEATURE_NO_TITLE);//设置无标题栏

        

        //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.page01, null));

        pageViews.add(inflater.inflate(R.layout.page02, null));

        pageViews.add(inflater.inflate(R.layout.page03, 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.view_pics, 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(ViewPagerGuideActivity.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());

    }

    

    

    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));  

            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);

                }

            }

            

        }

    }   

 }

 

主页面的布局:

<?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">

         

        <include layout="@layout/page_header"/>

   

        <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>

 

标题栏的布局:

<?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="wrap_content"



    android:orientation="horizontal"



    android:background="@drawable/title"



    android:gravity="center_vertical" >



    <Button 



        android:id="@+id/btn_left"



        android:layout_width="80dp"



        android:layout_height="30dp"



        android:text="返回"



        android:textSize="15sp"



        android:textColor="@android:color/white"



        android:background="@drawable/header_btn"



        android:layout_margin="5dp"/>



    <TextView 



        android:id="@+id/tvTitle"



        android:layout_width="wrap_content"



        android:layout_height="wrap_content"



        android:text="奥运快报"



        android:textSize="18sp"



        android:layout_weight="1"



        android:ellipsize="end"



        android:gravity="center_horizontal"/>



    <Button 



        android:id="@+id/btn_right"



        android:layout_width="80dp"



        android:layout_height="30dp"



        android:text="首页"



        android:textSize="15sp"



        android:textColor="@android:color/white"



        android:background="@drawable/header_btn"



        android:layout_margin="5dp"/> 



</LinearLayout>

 

子页面的布局:

<?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:background="@android:color/white" >



    <LinearLayout 



        android:layout_width="fill_parent"



        android:layout_height="wrap_content">



    <ImageView 



        android:layout_width="fill_parent"



        android:layout_height="wrap_content"



        android:src="@drawable/pic_lindan"/>



    </LinearLayout>



     

    <LinearLayout 



        android:layout_width="fill_parent"



        android:layout_height="wrap_content"



        android:layout_marginTop="10dp"



        android:layout_marginBottom="10dp"



        android:layout_marginLeft="30dp"



        android:layout_marginRight="30dp"



        android:background="@drawable/divider_horizontal_line">



    </LinearLayout>



    <LinearLayout 



        android:layout_width="fill_parent"



        android:layout_height="fill_parent">



        <TextView 



            android:layout_width="fill_parent"



            android:layout_height="wrap_content"



            android:layout_marginRight="30dp"



            android:layout_marginLeft="30dp"



            android:textColor="@android:color/black"



            android:text="@string/string_lindan"/>



    </LinearLayout> 



</LinearLayout>

 

 

转载自:http://www.cnblogs.com/eyu8874521/archive/2012/08/07/2626455.html

项目源码下载

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