本例子是通过ViewPager来实现广告自动轮播,并且实现小圆点的显示和点击监听等功能,算是比较实用的功能了.
此例子可自动播放、滑动和位置的随意调整，比较灵活,原项目中是添加了三级缓存的,不过想之后单写一个缓存的就先拿图片做了个DEMO.
如有什么好的建议,请大家提出来,共同进步..
效果图:
代码结构：主要就是3个文件，主类、viewpager适配器、页面的xml布局
原理网上有很多,所以直接在代码上写比较详细的注释,就不多说了- -
主类
<span style="font-size:14px;">package com.example.viewpagerimage;
import java.util.ArrayList;
import java.util.Timer;
import java.util.TimerTask;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import android.annotation.SuppressLint;
import android.app.Activity;
public class MainActivity extends Activity {
/*存储轮播图片*/
public int[] myBanner = {R.drawable.banner3,R.drawable.banner2,R.drawable.banner1};
/*轮播容器viewpager*/
public ViewPager mViewPager;
/*viewpager的适配器*/
public ViewPagerAdapter mViewPagerAdapter;
/*存放图片资源*/
public ArrayList<ImageView> mImageList;
/*存储广告轮播小圆点*/
public ImageView IVdicator[];
/*轮播小圆点对象*/
public View Vdicator;
/*布小圆点的布局参数*/
public LinearLayout.LayoutParams mLayoutParams;
/*定时器*/
public Timer mTimer;
public TimerTask mTimerTask;
public int mTimerNum = 0;
public final int PICTURE = 0x1;
@SuppressLint("HandlerLeak")
Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
switch(msg.what){
case PICTURE:
setmyPagerIndex();
break;
}
super.handleMessage(msg);
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// 获取屏幕高的5分之2
@SuppressWarnings("deprecation")
int screenHeight = this.getWindowManager().getDefaultDisplay().getHeight()/5*2;
//设置viewpager的位置
RelativeLayout layout = (RelativeLayout)this.findViewById(R.id.id_main_layout0);
RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams) layout.getLayoutParams();
params.height = screenHeight;
layout.setLayoutParams(params);
init();
}
/**
* 初始化组建
* */
public void init(){
mImageList = new ArrayList<ImageView>();
IVdicator = new ImageView[myBanner.length];
mLayoutParams = new LinearLayout.LayoutParams(10, 10);
//设置小圆点边框距离
mLayoutParams.setMargins(7, 10, 7, 10);
//小圆点对象
Vdicator = this.findViewById(R.id.viewpager_indicator);
//设置有多少个轮播图和小圆点
for(int i = 0; i < myBanner.length; i++){
ImageView nowImageView = new ImageView(this);
nowImageView.setImageResource(myBanner[i]);
mImageList.add(nowImageView);
nowImageView = new ImageView(this);
nowImageView.setLayoutParams(mLayoutParams);
nowImageView.setBackgroundResource(R.drawable.indicator);
IVdicator[i] = nowImageView;
//一个一个添加小圆点
((ViewGroup) Vdicator).addView(IVdicator[i]);
}
mViewPager = (ViewPager)this.findViewById(R.id.viewpager);
mViewPagerAdapter = new ViewPagerAdapter(mImageList,this);
//给viewpager添加适配器
mViewPager.setAdapter(mViewPagerAdapter);
//给viewpager添加滑动监听
mViewPager.setOnPageChangeListener(new OnPageChangeListener(){
@Override
public void onPageScrollStateChanged(int arg0) {}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {}
@Override
public void onPageSelected(int arg0) {
setDicator(arg0);
}
});
//默认第一个小圆点亮
setDicator(0);
startTimer();
}
/**
* 开启广告自动轮播
* */
public void startTimer(){
mTimer = new Timer();
mTimerTask = new TimerTask(){
@Override
public void run() {
mTimerNum++;
//需异步调用
mHandler.sendEmptyMessage(PICTURE);
}
};
//设置4秒轮播一次
mTimer.schedule(mTimerTask, 4 * 1000, 4 * 1000);
}
/**
* 切换广告动画
* */
public void setmyPagerIndex() {
try{
if (mTimerNum >= myBanner.length) {
mTimerNum = 0;
}
mViewPager.setCurrentItem(mTimerNum, true);
}catch(Exception e){
e.printStackTrace();
}
}
/**
* 设置小圆点的背景
* */
public void setDicator(int j){
//设置有多少个轮播图和小圆点
for(int i = 0; i < myBanner.length; i++){
if(i == j){
IVdicator[i].setBackgroundResource(R.drawable.indicator_focused);
}else{
IVdicator[i].setBackgroundResource(R.drawable.indicator);
}
}
}
/**
* 停止定时任务
* */
public void stopTask(){
try{
mTimer.cancel();
}catch(Exception e){
e.printStackTrace();
}
}
}
</span>
ViewPager适配器
<span style="font-size:14px;">package com.example.viewpagerimage;
import java.util.ArrayList;
import android.app.Activity;
import android.support.v4.view.PagerAdapter;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.ImageView;
public class ViewPagerAdapter extends PagerAdapter{
public ArrayList<ImageView> mImageView;
public Activity mActivity;
public ViewPagerAdapter(ArrayList<ImageView> mImageView ,Activity mActivity){
this.mImageView = mImageView;
this.mActivity = mActivity;
}
@Override
public int getCount() {
return mImageView.size();
}
/**
* 判断两张图片是否一致
*/
@Override
public boolean isViewFromObject(View arg0, Object arg1) {
return arg0 == arg1;
}
/**
* 向适配器返回要显示的图片
* */
@Override
public Object instantiateItem(ViewGroup container, int position) {
container.addView(mImageView.get(position));
//广告轮播图点击动作的监听
View mView = mImageView.get(position);
mView.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View arg0) {
;
}
});
return mImageView.get(position);
}
/**
* 从ViewGroup中移除当前view
* */
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView(mImageView.get(position));
}
}
</span>
例子唯一一个xml文件
<span style="font-size:14px;"><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:background="#000"
tools:context=".MainActivity" >
<RelativeLayout
android:id="@+id/id_main_layout0"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="4dip"
android:layout_marginRight="4dip" >
<android.support.v4.view.ViewPager
android:id="@+id/viewpager"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<LinearLayout
android:id="@+id/viewpager_indicator"
android:layout_width="100dip"
android:layout_height="20dip"
android:layout_alignBottom="@id/viewpager"
android:layout_alignParentRight="true"
android:layout_marginBottom="12dip"
android:orientation="horizontal" >
</LinearLayout>
</RelativeLayout>
</RelativeLayout></span>
Viewpager(上)--广告自动轮播
时间： 2024-07-31 02:18:40