Android开发-轮播图设计

待我称王封你为后i 2022-07-10 04:18 162阅读 0赞

在Android开发中，经常要用使用轮播图来展示广告或者其他信息，本文采用最少的代码实现最好的功能。使用本案例，可以十分方便的改变轮播图片的张数和内容。其功能如下：

1、定时轮播图片；

2、手动滑动图片；

3、导航按钮同步；

一、工程结构：

![Center][]

二、java代码如下：

package com.lyz.viewpage.activity; import java.util.ArrayList; import java.util.List; import java.util.concurrent.Executors; import java.util.concurrent.ScheduledExecutorService; import java.util.concurrent.TimeUnit; import android.app.Activity; import android.os.Bundle; import android.os.Handler; import android.support.v4.view.PagerAdapter; import android.support.v4.view.ViewPager; import android.view.Menu; import android.view.View; import android.view.ViewGroup; import android.widget.ImageView; import android.widget.TextView; /** * 图片轮播 * */ public class MainActivity extends Activity { private ViewPager mViewPaper; private List<ImageView> images; private List<View> dots; private int currentItem; private int oldPosition = 0; private int[] imageIds = new int[]{ R.drawable.ic_func_adv_1, R.drawable.ic_func_adv_2, R.drawable.ic_func_adv_3 }; private TextView title; private ViewPagerAdapter adapter; private ScheduledExecutorService scheduledExecutorService; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mViewPaper = (ViewPager) findViewById(R.id.vp); images = new ArrayList<ImageView>(); for(int i = 0; i < imageIds.length; i++){ ImageView imageView = new ImageView(this); imageView.setBackgroundResource(imageIds[i]); images.add(imageView); } dots = new ArrayList<View>(); dots.add(findViewById(R.id.dot_0)); dots.add(findViewById(R.id.dot_1)); dots.add(findViewById(R.id.dot_2)); adapter = new ViewPagerAdapter(); mViewPaper.setAdapter(adapter); mViewPaper.setOnPageChangeListener(new ViewPager.OnPageChangeListener() { @Override public void onPageSelected(int position) { dots.get(position).setBackgroundResource(R.drawable.dot_focused); dots.get(oldPosition).setBackgroundResource(R.drawable.dot_normal); oldPosition = position; currentItem = position; } @Override public void onPageScrolled(int arg0, float arg1, int arg2) { } @Override public void onPageScrollStateChanged(int arg0) { } }); } private class ViewPagerAdapter extends PagerAdapter{ @Override public int getCount() { return images.size(); } @Override public boolean isViewFromObject(View arg0, Object arg1) { return arg0 == arg1; } @Override public void destroyItem(ViewGroup view, int position, Object object) { view.removeView(images.get(position)); } @Override public Object instantiateItem(ViewGroup view, int position) { view.addView(images.get(position)); return images.get(position); } } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.main, menu); return true; } @Override protected void onStart() { super.onStart(); scheduledExecutorService = Executors.newSingleThreadScheduledExecutor(); scheduledExecutorService.scheduleWithFixedDelay( new ViewPageTask(), 2, 2, TimeUnit.SECONDS); } private class ViewPageTask implements Runnable{ @Override public void run() { currentItem = (currentItem + 1) % imageIds.length; mHandler.sendEmptyMessage(0); } } private Handler mHandler = new Handler(){ public void handleMessage(android.os.Message msg) { mViewPaper.setCurrentItem(currentItem); }; }; @Override protected void onStop() { super.onStop(); } }

**代码说明：**该代码在使用的时候，只需要改变上述

private int[] imageIds = new int[]{};里面的代码

，增加或者减少参与轮播的图片的张数即可。如果要改变里面的图片，请把文件命名为drawable文件夹里面的图片名，采用直接替换即可。十分方便。

三、xml文件代码：

四、效果图如下：

![Center 1][]

源代码：链接：http://download.csdn.net/detail/tiandixuanwuliang/9766821

[Center]: /images/20220709/621e976050474299a48bb124eca0597a.png
[Center 1]: /images/20220709/5e3a8d91ba81407f837aba3f6832b883.png