編輯:Android資訊
本文主要來分享一個Android UI開發中實現廣告Banner的輪播效果,因為Banner效果在Android應用中比較常見,所以我們也來嘗試實現以下。下圖是360影視大全的Android應用:
用紅框框住的那個效果就是小巫今天要分享的,先來思考一下會用到什麼控件?有什麼用戶體驗?
控件我們可能一下子就可以想到的自然是ViewPager,沒錯!用到的就是ViewPager,那麼它會有什麼用戶體驗呢,它可能有以下幾個體驗:
1. 間隔不停的切換圖片,指示器也跟著變
2. 點擊圖片可以跳轉到指定的頁面
/BannerAutoScrollDemo/res/layout/banner.xml
<?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" > <FrameLayout android:layout_width="match_parent" android:layout_height="210dp" > <android.support.v4.view.ViewPager android:id="@+id/vp" android:layout_width="match_parent" android:layout_height="210dp" /> <RelativeLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_gravity="bottom" android:background="@drawable/shadow_article" > <TextView android:id="@+id/tv_date" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_above="@+id/author_layout" android:layout_marginBottom="10dp" android:layout_marginLeft="10dp" android:maxLines="2" android:text="3月4日" android:textColor="@color/white" android:textSize="18sp" /> <TextView android:id="@+id/tv_title" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_above="@+id/author_layout" android:layout_marginBottom="10dp" android:layout_marginLeft="10dp" android:layout_marginRight="10dp" android:layout_toRightOf="@+id/tv_date" android:maxLines="2" android:text="我和令計劃只是同姓" android:textColor="@color/white" android:textSize="18sp" /> <RelativeLayout android:id="@+id/author_layout" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:layout_marginLeft="10dp" android:gravity="center_vertical" android:paddingBottom="20dp" > <TextView android:id="@+id/tv_pre" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="文章選題來自" android:textColor="@color/white" android:textSize="12sp" /> <TextView android:id="@+id/tv_topic_from" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_toRightOf="@+id/tv_pre" android:text="阿宅的" android:textColor="@color/white" android:textSize="12sp" /> <TextView android:id="@+id/tv_topic" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginLeft="10dp" android:layout_toRightOf="@+id/tv_topic_from" android:text="“我想知道令狐安和令計劃有什麼關系?”" android:textColor="@color/white" android:textSize="12sp" /> </RelativeLayout> </RelativeLayout> <LinearLayout android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginTop="10dip" android:layout_gravity="bottom|center_horizontal" android:layout_marginBottom="10dp" android:gravity="center" > <View android:id="@+id/v_dot0" android:background="@drawable/dot_focused" android:visibility="invisible" /> <View android:id="@+id/v_dot1" android:visibility="invisible"/> <View android:id="@+id/v_dot2" android:visibility="invisible"/> <View android:id="@+id/v_dot3" android:visibility="invisible"/> <View android:id="@+id/v_dot4" android:visibility="invisible" /> </LinearLayout> </FrameLayout> </LinearLayout>
一個ViewPager,下面五個指示點,注意每個點都有同樣的樣式,我們在style.xml中定義樣式:
/BannerAutoScrollDemo/res/values/styles.xml
<style name="dot_style"> <item name="android:layout_width">5dip</item> <item name="android:layout_height">5dip</item> <item name="android:background">@drawable/dot_normal</item> <item name="android:layout_marginLeft">1.5dip</item> <item name="android:layout_marginRight">1.5dip</item> </style>
/BannerAutoScrollDemo/res/drawable/dot_normal.xml
<?xml version="1.0" encoding="utf-8"?> <shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval" > <solid android:color="#33000000" /> <corners android:radius="5dip" /> </shape>
/BannerAutoScrollDemo/res/drawable/dot_focused.xml
<?xml version="1.0" encoding="utf-8"?> <shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval" > <solid android:color="#aaFFFFFF" /> <corners android:radius="5dip" /> </shape>
/BannerAutoScrollDemo/src/com/xiaowu/banner/demo/AdDomain.java
package com.xiaowu.banner.demo; /** * 廣告實體 * * @author wwj_748 * */ public class AdDomain { private String id; // 廣告id private String date; // 日期 private String title; // 標題 private String topicFrom; //選題來自 private String topic; // 選題 private String imgUrl; // 圖片url private boolean isAd; // 是否為廣告 private String startTime; // 廣告開始時間 private String endTime; // 廣告結束時間 private String targetUrl; // 目標url private int width; // 寬 private int height; // 高 private boolean available; // 是否可用 public String getId() { return id; } public void setId(String id) { this.id = id; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public String getImgUrl() { return imgUrl; } public void setImgUrl(String imgUrl) { this.imgUrl = imgUrl; } public boolean isAd() { return isAd; } public void setAd(boolean isAd) { this.isAd = isAd; } public String getDate() { return date; } public void setDate(String date) { this.date = date; } public String getTopic() { return topic; } public void setTopic(String topic) { this.topic = topic; } public String getTopicFrom() { return topicFrom; } public void setTopicFrom(String topicFrom) { this.topicFrom = topicFrom; } public String getStartTime() { return startTime; } public void setStartTime(String startTime) { this.startTime = startTime; } public String getEndTime() { return endTime; } public void setEndTime(String endTime) { this.endTime = endTime; } public String getTargetUrl() { return targetUrl; } public void setTargetUrl(String targetUrl) { this.targetUrl = targetUrl; } public int getWidth() { return width; } public void setWidth(int width) { this.width = width; } public int getHeight() { return height; } public void setHeight(int height) { this.height = height; } public boolean isAvailable() { return available; } public void setAvailable(boolean available) { this.available = available; } }
1. 定時切換
2. 切換圖片
3. 切換標題
4. 切換指示器
定時切換用到一個類:ScheduledExecutorService
作用是定時執行任務,我們這裡要做的定時任務是,2秒執行一次圖片切換
private void startAd() { scheduledExecutorService = Executors.newSingleThreadScheduledExecutor(); // 當Activity顯示出來後,每兩秒切換一次圖片顯示 scheduledExecutorService.scheduleAtFixedRate(new ScrollTask(), 1, 2, TimeUnit.SECONDS); }
定義子線程
private class ScrollTask implements Runnable { @Override public void run() { synchronized (adViewPager) { currentItem = (currentItem + 1) % imageViews.size(); handler.obtainMessage().sendToTarget(); } } }
通過handle來通知ViewPager進行視圖切換
private Handler handler = new Handler() { public void handleMessage(android.os.Message msg) { adViewPager.setCurrentItem(currentItem); }; };
我們提供模擬數據來進行測試
/** * 輪播廣播模擬數據 * * @return */ public static List<AdDomain> getBannerAd() { List<AdDomain> adList = new ArrayList<AdDomain>(); AdDomain adDomain = new AdDomain(); adDomain.setId("108078"); adDomain.setDate("3月4日"); adDomain.setTitle("我和令計劃只是同姓"); adDomain.setTopicFrom("阿宅"); adDomain.setTopic("我想知道令狐安和令計劃有什麼關系?"); adDomain.setImgUrl("http://g.hiphotos.baidu.com/image/w%3D310/sign=bb99d6add2c8a786be2a4c0f5708c9c7/d50735fae6cd7b8900d74cd40c2442a7d9330e29.jpg"); adDomain.setAd(false); adList.add(adDomain); AdDomain adDomain2 = new AdDomain(); adDomain2.setId("108078"); adDomain2.setDate("3月5日"); adDomain2.setTitle("我和令計劃只是同姓"); adDomain2.setTopicFrom("小巫"); adDomain2.setTopic("“我想知道令狐安和令計劃有什麼關系?”"); adDomain2 .setImgUrl("http://g.hiphotos.baidu.com/image/w%3D310/sign=7cbcd7da78f40ad115e4c1e2672e1151/eaf81a4c510fd9f9a1edb58b262dd42a2934a45e.jpg"); adDomain2.setAd(false); adList.add(adDomain2); AdDomain adDomain3 = new AdDomain(); adDomain3.setId("108078"); adDomain3.setDate("3月6日"); adDomain3.setTitle("我和令計劃只是同姓"); adDomain3.setTopicFrom("旭東"); adDomain3.setTopic("“我想知道令狐安和令計劃有什麼關系?”"); adDomain3 .setImgUrl("http://e.hiphotos.baidu.com/image/w%3D310/sign=392ce7f779899e51788e3c1572a6d990/8718367adab44aed22a58aeeb11c8701a08bfbd4.jpg"); adDomain3.setAd(false); adList.add(adDomain3); AdDomain adDomain4 = new AdDomain(); adDomain4.setId("108078"); adDomain4.setDate("3月7日"); adDomain4.setTitle("我和令計劃只是同姓"); adDomain4.setTopicFrom("小軟"); adDomain4.setTopic("“我想知道令狐安和令計劃有什麼關系?”"); adDomain4 .setImgUrl("http://d.hiphotos.baidu.com/image/w%3D310/sign=54884c82b78f8c54e3d3c32e0a282dee/a686c9177f3e670932e4cf9338c79f3df9dc55f2.jpg"); adDomain4.setAd(false); adList.add(adDomain4); AdDomain adDomain5 = new AdDomain(); adDomain5.setId("108078"); adDomain5.setDate("3月8日"); adDomain5.setTitle("我和令計劃只是同姓"); adDomain5.setTopicFrom("大熊"); adDomain5.setTopic("“我想知道令狐安和令計劃有什麼關系?”"); adDomain5 .setImgUrl("http://e.hiphotos.baidu.com/image/w%3D310/sign=66270b4fe8c4b7453494b117fffd1e78/0bd162d9f2d3572c7dad11ba8913632762d0c30d.jpg"); adDomain5.setAd(true); // 代表是廣告 adList.add(adDomain5); return adList; }
ViewPager邏輯處理
1. 填充數據(自定義Adapter)
2. 設置頁面切換監聽事件
3. 在自定義adapter中的instantiateItem方法設置ViewPager點擊事件
這裡我們的圖片是從網上下載的,用到了universal-image-loader-1.8.6-with-sources.jar這個類庫,可以實現異步加載圖片,具體使用查看代碼。
最後給出完整代碼:
/BannerAutoScrollDemo/src/com/xiaowu/banner/demo/MainActivity.java
package com.xiaowu.banner.demo; import java.io.File; 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.graphics.Bitmap; import android.os.Bundle; import android.os.Handler; 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.View; import android.view.View.OnClickListener; import android.view.ViewGroup; import android.widget.ImageView; import android.widget.ImageView.ScaleType; import android.widget.TextView; import com.nostra13.universalimageloader.cache.disc.impl.UnlimitedDiscCache; import com.nostra13.universalimageloader.cache.memory.impl.LruMemoryCache; import com.nostra13.universalimageloader.core.DisplayImageOptions; import com.nostra13.universalimageloader.core.ImageLoader; import com.nostra13.universalimageloader.core.ImageLoaderConfiguration; import com.nostra13.universalimageloader.core.assist.ImageScaleType; import com.nostra13.universalimageloader.core.assist.QueueProcessingType; public class MainActivity extends Activity { public static String IMAGE_CACHE_PATH = "imageloader/Cache"; // 圖片緩存路徑 private ViewPager adViewPager; private List<ImageView> imageViews;// 滑動的圖片集合 private List<View> dots; // 圖片標題正文的那些點 private List<View> dotList; private TextView tv_date; private TextView tv_title; private TextView tv_topic_from; private TextView tv_topic; private int currentItem = 0; // 當前圖片的索引號 // 定義的五個指示點 private View dot0; private View dot1; private View dot2; private View dot3; private View dot4; // 定時任務 private ScheduledExecutorService scheduledExecutorService; // 異步加載圖片 private ImageLoader mImageLoader; private DisplayImageOptions options; // 輪播banner的數據 private List<AdDomain> adList; private Handler handler = new Handler() { public void handleMessage(android.os.Message msg) { adViewPager.setCurrentItem(currentItem); }; }; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // 使用ImageLoader之前初始化 initImageLoader(); // 獲取圖片加載實例 mImageLoader = ImageLoader.getInstance(); options = new DisplayImageOptions.Builder() .showStubImage(R.drawable.top_banner_android) .showImageForEmptyUri(R.drawable.top_banner_android) .showImageOnFail(R.drawable.top_banner_android) .cacheInMemory(true).cacheOnDisc(true) .bitmapConfig(Bitmap.Config.RGB_565) .imageScaleType(ImageScaleType.EXACTLY).build(); initAdData(); startAd(); } /** * 初始化ImageLoader */ private void initImageLoader() { File cacheDir = com.nostra13.universalimageloader.utils.StorageUtils .getOwnCacheDirectory(getApplicationContext(), IMAGE_CACHE_PATH); DisplayImageOptions defaultOptions = new DisplayImageOptions.Builder() .cacheInMemory(true).cacheOnDisc(true).build(); ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder( this).defaultDisplayImageOptions(defaultOptions) .memoryCache(new LruMemoryCache(12 * 1024 * 1024)) .memoryCacheSize(12 * 1024 * 1024) .discCacheSize(32 * 1024 * 1024).discCacheFileCount(100) .discCache(new UnlimitedDiscCache(cacheDir)) .threadPriority(Thread.NORM_PRIORITY - 2) .tasksProcessingOrder(QueueProcessingType.LIFO).build(); ImageLoader.getInstance().init(config); } /** * 初始化廣告數據 */ private void initAdData() { // 廣告數據 adList = getBannerAd(); imageViews = new ArrayList<ImageView>(); // 點 dots = new ArrayList<View>(); dotList = new ArrayList<View>(); dot0 = findViewById(R.id.v_dot0); dot1 = findViewById(R.id.v_dot1); dot2 = findViewById(R.id.v_dot2); dot3 = findViewById(R.id.v_dot3); dot4 = findViewById(R.id.v_dot4); dots.add(dot0); dots.add(dot1); dots.add(dot2); dots.add(dot3); dots.add(dot4); tv_date = (TextView) findViewById(R.id.tv_date); tv_title = (TextView) findViewById(R.id.tv_title); tv_topic_from = (TextView) findViewById(R.id.tv_topic_from); tv_topic = (TextView) findViewById(R.id.tv_topic); adViewPager = (ViewPager) findViewById(R.id.vp); adViewPager.setAdapter(new MyAdapter());// 設置填充ViewPager頁面的適配器 // 設置一個監聽器,當ViewPager中的頁面改變時調用 adViewPager.setOnPageChangeListener(new MyPageChangeListener()); addDynamicView(); } private void addDynamicView() { // 動態添加圖片和下面指示的圓點 // 初始化圖片資源 for (int i = 0; i < adList.size(); i++) { ImageView imageView = new ImageView(this); // 異步加載圖片 mImageLoader.displayImage(adList.get(i).getImgUrl(), imageView, options); imageView.setScaleType(ScaleType.CENTER_CROP); imageViews.add(imageView); dots.get(i).setVisibility(View.VISIBLE); dotList.add(dots.get(i)); } } @Override protected void onResume() { super.onResume(); } private void startAd() { scheduledExecutorService = Executors.newSingleThreadScheduledExecutor(); // 當Activity顯示出來後,每兩秒切換一次圖片顯示 scheduledExecutorService.scheduleAtFixedRate(new ScrollTask(), 1, 2, TimeUnit.SECONDS); } private class ScrollTask implements Runnable { @Override public void run() { synchronized (adViewPager) { currentItem = (currentItem + 1) % imageViews.size(); handler.obtainMessage().sendToTarget(); } } } @Override protected void onStop() { super.onStop(); // 當Activity不可見的時候停止切換 scheduledExecutorService.shutdown(); } private class MyPageChangeListener implements OnPageChangeListener { private int oldPosition = 0; @Override public void onPageScrollStateChanged(int arg0) { } @Override public void onPageScrolled(int arg0, float arg1, int arg2) { } @Override public void onPageSelected(int position) { currentItem = position; AdDomain adDomain = adList.get(position); tv_title.setText(adDomain.getTitle()); // 設置標題 tv_date.setText(adDomain.getDate()); tv_topic_from.setText(adDomain.getTopicFrom()); tv_topic.setText(adDomain.getTopic()); dots.get(oldPosition).setBackgroundResource(R.drawable.dot_normal); dots.get(position).setBackgroundResource(R.drawable.dot_focused); oldPosition = position; } } private class MyAdapter extends PagerAdapter { @Override public int getCount() { return adList.size(); } @Override public Object instantiateItem(ViewGroup container, int position) { ImageView iv = imageViews.get(position); ((ViewPager) container).addView(iv); final AdDomain adDomain = adList.get(position); // 在這個方法裡面設置圖片的點擊事件 iv.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // 處理跳轉邏輯 } }); return iv; } @Override public void destroyItem(View arg0, int arg1, Object arg2) { ((ViewPager) arg0).removeView((View) arg2); } @Override public boolean isViewFromObject(View arg0, Object arg1) { return arg0 == arg1; } @Override public void restoreState(Parcelable arg0, ClassLoader arg1) { } @Override public Parcelable saveState() { return null; } @Override public void startUpdate(View arg0) { } @Override public void finishUpdate(View arg0) { } } /** * 輪播廣播模擬數據 * * @return */ public static List<AdDomain> getBannerAd() { List<AdDomain> adList = new ArrayList<AdDomain>(); AdDomain adDomain = new AdDomain(); adDomain.setId("108078"); adDomain.setDate("3月4日"); adDomain.setTitle("我和令計劃只是同姓"); adDomain.setTopicFrom("阿宅"); adDomain.setTopic("我想知道令狐安和令計劃有什麼關系?"); adDomain.setImgUrl("http://g.hiphotos.baidu.com/image/w%3D310/sign=bb99d6add2c8a786be2a4c0f5708c9c7/d50735fae6cd7b8900d74cd40c2442a7d9330e29.jpg"); adDomain.setAd(false); adList.add(adDomain); AdDomain adDomain2 = new AdDomain(); adDomain2.setId("108078"); adDomain2.setDate("3月5日"); adDomain2.setTitle("我和令計劃只是同姓"); adDomain2.setTopicFrom("小巫"); adDomain2.setTopic("“我想知道令狐安和令計劃有什麼關系?”"); adDomain2 .setImgUrl("http://g.hiphotos.baidu.com/image/w%3D310/sign=7cbcd7da78f40ad115e4c1e2672e1151/eaf81a4c510fd9f9a1edb58b262dd42a2934a45e.jpg"); adDomain2.setAd(false); adList.add(adDomain2); AdDomain adDomain3 = new AdDomain(); adDomain3.setId("108078"); adDomain3.setDate("3月6日"); adDomain3.setTitle("我和令計劃只是同姓"); adDomain3.setTopicFrom("旭東"); adDomain3.setTopic("“我想知道令狐安和令計劃有什麼關系?”"); adDomain3 .setImgUrl("http://e.hiphotos.baidu.com/image/w%3D310/sign=392ce7f779899e51788e3c1572a6d990/8718367adab44aed22a58aeeb11c8701a08bfbd4.jpg"); adDomain3.setAd(false); adList.add(adDomain3); AdDomain adDomain4 = new AdDomain(); adDomain4.setId("108078"); adDomain4.setDate("3月7日"); adDomain4.setTitle("我和令計劃只是同姓"); adDomain4.setTopicFrom("小軟"); adDomain4.setTopic("“我想知道令狐安和令計劃有什麼關系?”"); adDomain4 .setImgUrl("http://d.hiphotos.baidu.com/image/w%3D310/sign=54884c82b78f8c54e3d3c32e0a282dee/a686c9177f3e670932e4cf9338c79f3df9dc55f2.jpg"); adDomain4.setAd(false); adList.add(adDomain4); AdDomain adDomain5 = new AdDomain(); adDomain5.setId("108078"); adDomain5.setDate("3月8日"); adDomain5.setTitle("我和令計劃只是同姓"); adDomain5.setTopicFrom("大熊"); adDomain5.setTopic("“我想知道令狐安和令計劃有什麼關系?”"); adDomain5 .setImgUrl("http://e.hiphotos.baidu.com/image/w%3D310/sign=66270b4fe8c4b7453494b117fffd1e78/0bd162d9f2d3572c7dad11ba8913632762d0c30d.jpg"); adDomain5.setAd(true); // 代表是廣告 adList.add(adDomain5); return adList; } }
源碼下載:http://download.csdn.net/detail/wwj_748/8498749
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