ViewPaper

当应用程序更新的时候,打开后那个查看新特性的界面其实就是用ViewPaper实现的。

以下是不完整代码,不过强烈建议用一个int数组存储图片资源,方便给定下标后调用。这样一些语句就不用重复写,直接用个for()简洁明了。

(为了方便,我们暂把java代码中setContentView用到的xml称之为主xml)

主xml文件

<?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">

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

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

    <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_gravity="bottom"
            android:layout_marginBottom="30dp"
            android:gravity="center_horizontal">

        <ImageView
                android:id="@+id/page0"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:scaleType="matrix"
                android:src="@drawable/page_now"/>

        <ImageView
                android:id="@+id/page1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="10dp"
                android:scaleType="matrix"
                android:src="@drawable/page"/>

        <ImageView
                android:id="@+id/page2"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="10dp"
                android:scaleType="matrix"
                android:src="@drawable/page"/>

        <ImageView
                android:id="@+id/page3"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="10dp"
                android:scaleType="matrix"
                android:src="@drawable/page"/>

        <ImageView
                android:id="@+id/page4"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="10dp"
                android:scaleType="matrix"
                android:src="@drawable/page"/>

        <ImageView
                android:id="@+id/page5"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="10dp"
                android:scaleType="matrix"
                android:src="@drawable/page"/>

    </LinearLayout>

</FrameLayout>
View Code

Java代码

package cn.buaa.myweixin;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
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.widget.ImageView;

import java.util.ArrayList;

public class Whatsnew extends Activity
{
    private ViewPager mViewPager;
    private ImageView mPage0;
    private ImageView mPage1;
    private ImageView mPage2;
    private ImageView mPage3;
    private ImageView mPage4;
    private ImageView mPage5;


    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.whatsnew_viewpager);
        mViewPager = (ViewPager) findViewById(R.id.whatsnew_viewpager);
        mViewPager.setOnPageChangeListener(new MyOnPageChangeListener());
        //mPage是小点
        mPage0 = (ImageView) findViewById(R.id.page0);
        mPage1 = (ImageView) findViewById(R.id.page1);
        mPage2 = (ImageView) findViewById(R.id.page2);
        mPage3 = (ImageView) findViewById(R.id.page3);
        mPage4 = (ImageView) findViewById(R.id.page4);
        mPage5 = (ImageView) findViewById(R.id.page5);
        //将要分页显示的View装入数组中
        //view是一个xml,
        LayoutInflater mLi = LayoutInflater.from(this);
        View view1 = mLi.inflate(R.layout.whats1, null);    //whats1上面是文字和图片(背景)
        View view2 = mLi.inflate(R.layout.whats2, null);
        View view3 = mLi.inflate(R.layout.whats3, null);
        View view4 = mLi.inflate(R.layout.whats4, null);
        View view5 = mLi.inflate(R.layout.whats5, null);
        View view6 = mLi.inflate(R.layout.whats6, null);
        //每个页面的view数据
        final ArrayList<View> views = new ArrayList<View>();
        views.add(view1);
        views.add(view2);
        views.add(view3);
        views.add(view4);
        views.add(view5);
        views.add(view6);
        //填充ViewPager的数据适配器
        PagerAdapter mPagerAdapter = new PagerAdapter()
        {
            @Override
            public boolean isViewFromObject(View arg0, Object arg1)
            {
                return arg0 == arg1;
            }

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

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

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

    public class MyOnPageChangeListener implements OnPageChangeListener
    {
        @Override
        public void onPageSelected(int arg0)
        {
            //switch写的,我不建议这么做,应该把mPage1234等写成一个数组方便存取
            //参照http://blog.csdn.net/notice520/article/details/7454568/
            switch (arg0)
            {
                case 0:
                    mPage0.setImageDrawable(getResources().getDrawable(R.drawable.page_now));
                    mPage1.setImageDrawable(getResources().getDrawable(R.drawable.page));
                    break;
                case 1:
                    mPage1.setImageDrawable(getResources().getDrawable(R.drawable.page_now));
                    mPage0.setImageDrawable(getResources().getDrawable(R.drawable.page));
                    mPage2.setImageDrawable(getResources().getDrawable(R.drawable.page));
                    break;
                case 2:
                    mPage2.setImageDrawable(getResources().getDrawable(R.drawable.page_now));
                    mPage1.setImageDrawable(getResources().getDrawable(R.drawable.page));
                    mPage3.setImageDrawable(getResources().getDrawable(R.drawable.page));
                    break;
                case 3:
                    mPage3.setImageDrawable(getResources().getDrawable(R.drawable.page_now));
                    mPage4.setImageDrawable(getResources().getDrawable(R.drawable.page));
                    mPage2.setImageDrawable(getResources().getDrawable(R.drawable.page));
                    break;
                case 4:
                    mPage4.setImageDrawable(getResources().getDrawable(R.drawable.page_now));
                    mPage3.setImageDrawable(getResources().getDrawable(R.drawable.page));
                    mPage5.setImageDrawable(getResources().getDrawable(R.drawable.page));
                    break;
                case 5:
                    mPage5.setImageDrawable(getResources().getDrawable(R.drawable.page_now));
                    mPage4.setImageDrawable(getResources().getDrawable(R.drawable.page));
                    break;
            }
        }

        @Override
        public void onPageScrolled(int arg0, float arg1, int arg2)
        {
            //Toast.makeText(Whatsnew.this, "当前页面被滑动", Toast.LENGTH_SHORT).show();
        }

        @Override
        public void onPageScrollStateChanged(int arg0)
        {
            //Toast.makeText(Whatsnew.this, "滑动状态改变", Toast.LENGTH_SHORT).show();
        }
    }

}
View Code

whats5.xml文件(其他类似)

<?xml version="1.0" encoding="UTF-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
                android:orientation="vertical"
                android:background="@drawable/w05"
                android:layout_width="fill_parent"
                android:layout_height="fill_parent">

    <TextView
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:text="\n你还可以透过朋友圈\n和朋友们分享彼此的生活"
            android:layout_alignParentTop="true"
            android:layout_marginTop="35dp"
            android:textSize="22sp"
            android:textColor="#fff"/>
</RelativeLayout>
View Code

 

写得不是很详细,是网上的一段代码,详细可参照http://blog.csdn.net/notice520/article/details/7454568/,谢谢博主的博文,写的很好。

 

  总结一下步骤

  • 得到图片的view(主xml中没有的)->图片添加入Array或List ->利用Array(List)写适配器 ->利用适配器设置ViewPaper
  • 重写ViewPaper的监听函数以改变小圆点的状态

    OnPageChangeListener包含的函数如下:

    1)onPageScrollStateChanged(int) 当滑动状态改变时调用
    2)onPageScrolled(int, float, int) 当当前页面被滑动时调用
    3)onPageSelected(int) 当新的页面被选中时调用

  • 主xml文件结构如下:

    <RelativeLayout/FrameLayout
      <android.support.v4.view.ViewPager
      <LinearLayout
        <ImageView (小圆点)
        <ImageView (小圆点)
        ……

  • 除了主xml,我们每个界面都要有一个xml与之对应,包含的图片就设置为xml的背景,再添加文字,这样一张页面各对应一个xml。最后在Java代码中用LayoutInflatert填充我们要添加的xml,将这几个含xml的view加入到Array/List以配置适配器,再设置ViewPaper

 

ps.ViewPaper setCurrentItem(int item) 根据编号显示相应的"图片"。

posted @ 2013-07-21 22:24  Norcy  阅读(1900)  评论(0编辑  收藏  举报