1、viewpager在广告头里经常运用到,它是android3后出现的控件,在因此在添加的时候android.support.v4.view.ViewPager.class里,因此在xml定义的时候需要加全名称,同时注意不要后缀名class。下面从demo里学习viewpager的运用。
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context="com.example.viewdemo.MainActivity$PlaceholderFragment" android:background="@android:color/darker_gray" > <android.support.v4.view.ViewPager android:id="@+id/img_view" android:layout_width="fill_parent" android:layout_height="200dp" /> <!-- 这里background设置后6位为rgb的值,前面是透明度参数,33为半透明 --> <LinearLayout android:layout_width="fill_parent" android:layout_height="wrap_content" android:orientation="vertical" android:background="#33000000" android:layout_alignBottom="@+id/img_view" > <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_horizontal" android:textColor="@android:color/white" android:paddingTop="5dp" android:id="@+id/title" /> <!-- 这里定义一个空的线性布局,在代码里加入点的ui , 注意gravity的运用是在容器里控件的排列,用于ui是ui在它布局里的排列--> <LinearLayout android:id="@+id/dians" android:layout_width="fill_parent" android:layout_height="wrap_content" android:orientation="horizontal" android:gravity="center_horizontal" android:paddingBottom="10dp" android:layout_marginTop="2dp" > </LinearLayout> </LinearLayout> </RelativeLayout>
2、java的activity代码:
public class MainActivity extends Activity { private ViewPager viewpager; private ArrayList <ImageView> imageviews; private int number; private View[] points; private LinearLayout dians; private String[] titles; private TextView title; private boolean flag=true;//标识应用程序是否为可见 public Handler handler=new Handler(){ @Override public void handleMessage(Message msg) { int a=msg.what; points[a].setEnabled(true); a++; int c=a%number; viewpager.setCurrentItem(c); title.setText(titles[c]); points[c].setEnabled(false); super.handleMessage(msg); } }; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); dians=(LinearLayout) findViewById(R.id.dians); title=(TextView) findViewById(R.id.title); number=5; initview(); viewpager.setOnPageChangeListener(new PagerLisetner()); setpointsOnclick(); Thread pagermove=new Thread(new ThreadpageChange()); pagermove.start(); } class ThreadpageChange implements Runnable { @Override public void run() { while(true){ synchronized (MainActivity.class) { if(flag){ try { Thread.sleep(2000); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } int a=viewpager.getCurrentItem(); Message msg=new Message(); msg.what=a; handler.sendMessage(msg); } else try { MainActivity.class.wait(); } catch (InterruptedException e) { e.printStackTrace(); } } } } } //页面改变监听器 class PagerLisetner implements OnPageChangeListener { @Override public void onPageScrollStateChanged(int arg0) { } @Override public void onPageScrolled(int arg0, float arg1, int arg2) { } @Override public void onPageSelected(int arg0) { title.setText(titles[arg0]); for(int x=0;x<number;x++ ) { View v=dians.getChildAt(x); if(x==arg0) v.setEnabled(false); else v.setEnabled(true); } } } //设置点被点击的监听器 public void setpointsOnclick() { for(int x=0;x<number;x++) { View v=points[x]; v.setTag(x); v.setOnClickListener(new PointOnclickLinstener()); } } //点被点击的监听器 class PointOnclickLinstener implements OnClickListener { @Override public void onClick(View v) { System.out.println("点击了。。。"+v.getTag()); int index=(Integer) v.getTag(); title.setText(titles[index]); points[index].setEnabled(true); viewpager.setCurrentItem(index); } } //初始化界面 public void initview() { //将每张图片创建一个Imgeview,并存起来 int[] images={ R.drawable.a, R.drawable.b, R.drawable.c, R.drawable.d, R.drawable.e }; imageviews=new ArrayList<ImageView>(); for(int i=0;i<number;i++) { ImageView im=new ImageView(this); im.setBackground(getResources().getDrawable(images[i])); imageviews.add(im); } viewpager=(ViewPager) findViewById(R.id.img_view); viewpager.setAdapter(new VpAdapter()); //添加点 addpoints(); //初始化标题 addTitle(); title.setText(titles[0]); points[0].setEnabled(false); } //添加点 public void addpoints() { points=new View[number]; for(int i=0;i<number;i++) { View v=new View(this); //创建子视图 LayoutParams pa=new LayoutParams(8, 8); pa.leftMargin=10; v.setLayoutParams(pa);//使点按照子视图格式形成view v.setBackgroundResource(R.drawable.bg);//设置点的背景,这里的bg是选择器,下面介绍 v.setEnabled(true); //将创建的子视图点添加到LinearLayout中 points[i]=v; dians.addView(v); } } //添加标题 public void addTitle() { titles=new String[]{ "巩俐不低俗,我就不能低俗", "朴树邮回来啦!唱经典老歌引万人大合唱", "揭秘北京电影如何升级", "乐视网TV版大派送", "热血屌丝的反杀" }; } class VpAdapter extends PagerAdapter { @Override public Object instantiateItem(ViewGroup container, int position) { viewpager.addView(imageviews.get(position)); return imageviews.get(position); } @Override public void destroyItem(ViewGroup container, int position, Object object) { //从右向左划就删除当前页,从右往左就加,即执行instantiateItem,当1时候一下跳到5时,其实add了前面4个(仅我的看法) viewpager.removeView(imageviews.get(position)); } @Override public int getCount() { return imageviews.size(); } @Override public boolean isViewFromObject(View arg0, Object arg1) { return arg0==arg1; } } //重写下面activity生命周期是当程序后台时为了将资源消耗,让子线程等待 @Override protected void onResume() { if(!flag) MainActivity.class.notify(); super.onResume(); } @Override protected void onPause() { flag=false; super.onPause(); } }
3、下面介绍如何在xml文件里画图的,首先给出我的工程目录:
可以看出,文件里定义了dian_normal,和dian_select,这是点在被选择和没有被选择的时候的图像,bg其实就是这两种图像的选择器,当可点击时候选normal,不可点击时候显示select。画图是在drawable里选择shape,然后再里面可以画几种简单的形状:
normal的xml文件:android:shape=oval是指画圆,下面的corners 里radius是圆半径、solid是填充颜色。
<?xml version="1.0" encoding="utf-8"?> <shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval"> <corners android:radius="0.5dp" /> <solid android:color="@android:color/background_dark" /> </shape>
select的xml文件
<?xml version="1.0" encoding="utf-8"?> <shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval"> <corners android:radius="0.5dp" /> <solid android:color="@android:color/white" /> </shape>
下面是选择器:db.xml,即当enable=true时候选择一种drawable,false时候选择另一个
<?xml version="1.0" encoding="utf-8"?> <selector xmlns:android="http://schemas.android.com/apk/res/android" > <item android:state_enabled="false" android:drawable="@drawable/dian_select"></item> <item android:state_enabled="true" android:drawable="@drawable/dian_normal"></item> </selector>
时间: 2024-10-12 12:35:44