Android開發之ViewPager實現輪播圖（輪播廣告）效果的自定義View---轉

最近開發中須要作一個相似京東首頁那樣的廣告輪播效果，因而採用ViewPager本身自定義了一個輪播圖效果的View。html

主要原理就是利用定時任務器定時切換ViewPager的頁面。java

主頁面佈局實現以下：android

 
   01. 
   <?xml version="1.0" encoding="utf-8"?> 
  
   02. 
     
   03. 
   <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
  
   04. 
   android:layout_width="match_parent" 
  
   05. 
   android:layout_height="match_parent"> 
  
   06. 
     
   07. 
   <android.support.v4.view.ViewPager 
  
   08. 
   android:id="@+id/viewPager" 
  
   09. 
   android:layout_width="match_parent" 
  
   10. 
   android:layout_height="match_parent" /> 
  
   11. 
     
   12. 
   <LinearLayout 
  
   13. 
   android:layout_width="match_parent" 
  
   14. 
   android:layout_height="wrap_content" 
  
   15. 
   android:layout_alignParentBottom="true" 
  
   16. 
   android:padding="5dp" 
  
   17. 
   android:gravity="center" 
  
   18. 
   android:orientation="horizontal"> 
  
   19. 
     
   20. 
   <View 
  
   21. 
   android:id="@+id/v_dot1" 
  
   22. 
   android:layout_width="8dp" 
  
   23. 
   android:layout_height="8dp" 
  
   24. 
   android:background="@drawable/dot_black" /> 
  
   25. 
     
   26. 
   <View 
  
   27. 
   android:id="@+id/v_dot2" 
  
   28. 
   android:layout_width="8dp" 
  
   29. 
   android:layout_height="8dp" 
  
   30. 
   android:layout_marginLeft="5dp" 
  
   31. 
   android:background="@drawable/dot_white" /> 
  
   32. 
     
   33. 
   <View 
  
   34. 
   android:id="@+id/v_dot3" 
  
   35. 
   android:layout_width="8dp" 
  
   36. 
   android:layout_height="8dp" 
  
   37. 
   android:layout_marginLeft="5dp" 
  
   38. 
   android:background="@drawable/dot_white" /> 
  
   39. 
     
   40. 
   <View 
  
   41. 
   android:id="@+id/v_dot4" 
  
   42. 
   android:layout_width="8dp" 
  
   43. 
   android:layout_height="8dp" 
  
   44. 
   android:layout_marginLeft="5dp" 
  
   45. 
   android:background="@drawable/dot_white" /> 
  
   46. 
     
   47. 
   <View 
  
   48. 
   android:id="@+id/v_dot5" 
  
   49. 
   android:layout_width="8dp" 
  
   50. 
   android:layout_height="8dp" 
  
   51. 
   android:layout_marginLeft="5dp" 
  
   52. 
   android:background="@drawable/dot_white" /> 
  
   53. 
     
   54. 
   </LinearLayout> 
  
   55. 
   </RelativeLayout>

輪播效果視圖類代碼實現以下：ide

 
   001. 
   package com.czm.customview; 
  
   002. 
     
   003. 
   import java.util.ArrayList; 
  
   004. 
   import java.util.List; 
  
   005. 
   import java.util.concurrent.Executors; 
  
   006. 
   import java.util.concurrent.ScheduledExecutorService; 
  
   007. 
   import java.util.concurrent.TimeUnit; 
  
   008. 
     
   009. 
   import android.content.Context; 
  
   010. 
   import android.graphics.drawable.Drawable; 
  
   011. 
   import android.os.Handler; 
  
   012. 
   import android.os.Message; 
  
   013. 
   import android.os.Parcelable; 
  
   014. 
   import android.support.v4.view.PagerAdapter; 
  
   015. 
   import android.support.v4.view.ViewPager; 
  
   016. 
   import android.support.v4.view.ViewPager.OnPageChangeListener; 
  
   017. 
   import android.util.AttributeSet; 
  
   018. 
   import android.view.LayoutInflater; 
  
   019. 
   import android.view.View; 
  
   020. 
   import android.widget.FrameLayout; 
  
   021. 
   import android.widget.ImageView; 
  
   022. 
   import android.widget.ImageView.ScaleType; 
  
   023. 
     
   024. 
     
   025. 
   /** 
  
   026. 
   * ViewPager實現的輪播圖廣告自定義視圖，如京東首頁的廣告輪播圖效果； 
  
   027. 
   * 既支持自動輪播頁面也支持手勢滑動切換頁面 
  
   028. 
   * @author caizhiming 
  
   029. 
   * 
  
   030. 
   */ 
  
   031. 
     
   032. 
   public class SlideShowView extends FrameLayout { 
  
   033. 
     
   034. 
   //輪播圖圖片數量 
  
   035. 
   private final static int IMAGE_COUNT = 5; 
  
   036. 
   //自動輪播的時間間隔 
  
   037. 
   private final static int TIME_INTERVAL = 5; 
  
   038. 
   //自動輪播啓用開關 
  
   039. 
   private final static boolean isAutoPlay = true; 
  
   040. 
     
   041. 
   //自定義輪播圖的資源ID 
  
   042. 
   private int[] imagesResIds; 
  
   043. 
   //放輪播圖片的ImageView 的list 
  
   044. 
   private List<ImageView> imageViewsList; 
  
   045. 
   //放圓點的View的list 
  
   046. 
   private List<View> dotViewsList; 
  
   047. 
     
   048. 
   private ViewPager viewPager; 
  
   049. 
   //當前輪播頁 
  
   050. 
   private int currentItem  = 0; 
  
   051. 
   //定時任務 
  
   052. 
   private ScheduledExecutorService scheduledExecutorService; 
  
   053. 
   //Handler 
  
   054. 
   private Handler handler = new Handler(){ 
  
   055. 
     
   056. 
   @Override 
  
   057. 
   public void handleMessage(Message msg) { 
  
   058. 
   // TODO Auto-generated method stub 
  
   059. 
   super.handleMessage(msg); 
  
   060. 
   viewPager.setCurrentItem(currentItem); 
  
   061. 
   } 
  
   062. 
     
   063. 
   }; 
  
   064. 
     
   065. 
   public SlideShowView(Context context) { 
  
   066. 
   this(context,null); 
  
   067. 
   // TODO Auto-generated constructor stub 
  
   068. 
   } 
  
   069. 
   public SlideShowView(Context context, AttributeSet attrs) { 
  
   070. 
   this(context, attrs, 0); 
  
   071. 
   // TODO Auto-generated constructor stub 
  
   072. 
   } 
  
   073. 
   public SlideShowView(Context context, AttributeSet attrs, int defStyle) { 
  
   074. 
   super(context, attrs, defStyle); 
  
   075. 
   // TODO Auto-generated constructor stub 
  
   076. 
   initData(); 
  
   077. 
   initUI(context); 
  
   078. 
   if(isAutoPlay){ 
  
   079. 
   startPlay(); 
  
   080. 
   } 
  
   081. 
     
   082. 
   } 
  
   083. 
   /** 
  
   084. 
   * 開始輪播圖切換 
  
   085. 
   */ 
  
   086. 
   private void startPlay(){ 
  
   087. 
   scheduledExecutorService = Executors.newSingleThreadScheduledExecutor(); 
  
   088. 
   scheduledExecutorService.scheduleAtFixedRate(new SlideShowTask(), 1, 4, TimeUnit.SECONDS); 
  
   089. 
   } 
  
   090. 
   /** 
  
   091. 
   * 中止輪播圖切換 
  
   092. 
   */ 
  
   093. 
   private void stopPlay(){ 
  
   094. 
   scheduledExecutorService.shutdown(); 
  
   095. 
   } 
  
   096. 
   /** 
  
   097. 
   * 初始化相關Data 
  
   098. 
   */ 
  
   099. 
   private void initData(){ 
  
   100. 
   imagesResIds = new int[]{ 
  
   101. 
   R.drawable.pic1, 
  
   102. 
   R.drawable.pic2, 
  
   103. 
   R.drawable.pic3, 
  
   104. 
   R.drawable.pic4, 
  
   105. 
   R.drawable.pic5, 
  
   106. 
     
   107. 
   }; 
  
   108. 
   imageViewsList = new ArrayList<ImageView>(); 
  
   109. 
   dotViewsList = new ArrayList<View>(); 
  
   110. 
     
   111. 
   } 
  
   112. 
   /** 
  
   113. 
   * 初始化Views等UI 
  
   114. 
   */ 
  
   115. 
   private void initUI(Context context){ 
  
   116. 
   LayoutInflater.from(context).inflate(R.layout.layout_slideshow, this, true); 
  
   117. 
   for(int imageID : imagesResIds){ 
  
   118. 
   ImageView view =  new ImageView(context); 
  
   119. 
   view.setImageResource(imageID); 
  
   120. 
   view.setScaleType(ScaleType.FIT_XY); 
  
   121. 
   imageViewsList.add(view); 
  
   122. 
   } 
  
   123. 
   dotViewsList.add(findViewById(R.id.v_dot1)); 
  
   124. 
   dotViewsList.add(findViewById(R.id.v_dot2)); 
  
   125. 
   dotViewsList.add(findViewById(R.id.v_dot3)); 
  
   126. 
   dotViewsList.add(findViewById(R.id.v_dot4)); 
  
   127. 
   dotViewsList.add(findViewById(R.id.v_dot5)); 
  
   128. 
     
   129. 
   viewPager = (ViewPager) findViewById(R.id.viewPager); 
  
   130. 
   viewPager.setFocusable(true); 
  
   131. 
     
   132. 
   viewPager.setAdapter(new MyPagerAdapter()); 
  
   133. 
   viewPager.setOnPageChangeListener(new MyPageChangeListener()); 
  
   134. 
   } 
  
   135. 
     
   136. 
   /** 
  
   137. 
   * 填充ViewPager的頁面適配器 
  
   138. 
   * @author caizhiming 
  
   139. 
   */ 
  
   140. 
   private class MyPagerAdapter  extends PagerAdapter{ 
  
   141. 
     
   142. 
   @Override 
  
   143. 
   public void destroyItem(View container, int position, Object object) { 
  
   144. 
   // TODO Auto-generated method stub 
  
   145. 
   //((ViewPag.er)container).removeView((View)object); 
  
   146. 
   ((ViewPager)container).removeView(imageViewsList.get(position)); 
  
   147. 
   } 
  
   148. 
     
   149. 
   @Override 
  
   150. 
   public Object instantiateItem(View container, int position) { 
  
   151. 
   // TODO Auto-generated method stub 
  
   152. 
   ((ViewPager)container).addView(imageViewsList.get(position)); 
  
   153. 
   return imageViewsList.get(position); 
  
   154. 
   } 
  
   155. 
     
   156. 
   @Override 
  
   157. 
   public int getCount() { 
  
   158. 
   // TODO Auto-generated method stub 
  
   159. 
   return imageViewsList.size(); 
  
   160. 
   } 
  
   161. 
     
   162. 
   @Override 
  
   163. 
   public boolean isViewFromObject(View arg0, Object arg1) { 
  
   164. 
   // TODO Auto-generated method stub 
  
   165. 
   return arg0 == arg1; 
  
   166. 
   } 
  
   167. 
   @Override 
  
   168. 
   public void restoreState(Parcelable arg0, ClassLoader arg1) { 
  
   169. 
   // TODO Auto-generated method stub 
  
   170. 
     
   171. 
   } 
  
   172. 
     
   173. 
   @Override 
  
   174. 
   public Parcelable saveState() { 
  
   175. 
   // TODO Auto-generated method stub 
  
   176. 
   return null; 
  
   177. 
   } 
  
   178. 
     
   179. 
   @Override 
  
   180. 
   public void startUpdate(View arg0) { 
  
   181. 
   // TODO Auto-generated method stub 
  
   182. 
     
   183. 
   } 
  
   184. 
     
   185. 
   @Override 
  
   186. 
   public void finishUpdate(View arg0) { 
  
   187. 
   // TODO Auto-generated method stub 
  
   188. 
     
   189. 
   } 
  
   190. 
     
   191. 
   } 
  
   192. 
   /** 
  
   193. 
   * ViewPager的監聽器 
  
   194. 
   * 當ViewPager中頁面的狀態發生改變時調用 
  
   195. 
   * @author caizhiming 
  
   196. 
   */ 
  
   197. 
   private class MyPageChangeListener implements OnPageChangeListener{ 
  
   198. 
     
   199. 
   boolean isAutoPlay = false; 
  
   200. 
     
   201. 
   @Override 
  
   202. 
   public void onPageScrollStateChanged(int arg0) { 
  
   203. 
   // TODO Auto-generated method stub 
  
   204. 
   switch (arg0) { 
  
   205. 
   case 1:// 手勢滑動，空閒中 
  
   206. 
   isAutoPlay = false; 
  
   207. 
   break; 
  
   208. 
   case 2:// 界面切換中 
  
   209. 
   isAutoPlay = true; 
  
   210. 
   break; 
  
   211. 
   case 0:// 滑動結束，即切換完畢或者加載完畢 
  
   212. 
   // 當前爲最後一張，此時從右向左滑，則切換到第一張 
  
   213. 
   if (viewPager.getCurrentItem() == viewPager.getAdapter().getCount() - 1 && !isAutoPlay) { 
  
   214. 
   viewPager.setCurrentItem(0); 
  
   215. 
   } 
  
   216. 
   // 當前爲第一張，此時從左向右滑，則切換到最後一張 
  
   217. 
   else if (viewPager.getCurrentItem() == 0 && !isAutoPlay) { 
  
   218. 
   viewPager.setCurrentItem(viewPager.getAdapter().getCount() - 1); 
  
   219. 
   } 
  
   220. 
   break; 
  
   221. 
   } 
  
   222. 
   } 
  
   223. 
     
   224. 
   @Override 
  
   225. 
   public void onPageScrolled(int arg0, float arg1, int arg2) { 
  
   226. 
   // TODO Auto-generated method stub 
  
   227. 
     
   228. 
   } 
  
   229. 
     
   230. 
   @Override 
  
   231. 
   public void onPageSelected(int pos) { 
  
   232. 
   // TODO Auto-generated method stub 
  
   233. 
     
   234. 
   currentItem = pos; 
  
   235. 
   for(int i=0;i < dotViewsList.size();i++){ 
  
   236. 
   if(i == pos){ 
  
   237. 
   ((View)dotViewsList.get(pos)).setBackgroundResource(R.drawable.dot_black); 
  
   238. 
   }else { 
  
   239. 
   ((View)dotViewsList.get(i)).setBackgroundResource(R.drawable.dot_white); 
  
   240. 
   } 
  
   241. 
   } 
  
   242. 
   } 
  
   243. 
     
   244. 
   } 
  
   245. 
     
   246. 
   /** 
  
   247. 
   *執行輪播圖切換任務 
  
   248. 
   *@author caizhiming 
  
   249. 
   */ 
  
   250. 
   private class SlideShowTask implements Runnable{ 
  
   251. 
     
   252. 
   @Override 
  
   253. 
   public void run() { 
  
   254. 
   // TODO Auto-generated method stub 
  
   255. 
   synchronized (viewPager) { 
  
   256. 
   currentItem = (currentItem+1)%imageViewsList.size(); 
  
   257. 
   handler.obtainMessage().sendToTarget(); 
  
   258. 
   } 
  
   259. 
   } 
  
   260. 
     
   261. 
   } 
  
   262. 
   /** 
  
   263. 
   * 銷燬ImageView資源，回收內存 
  
   264. 
   * @author caizhiming 
  
   265. 
   */ 
  
   266. 
   private void destoryBitmaps() { 
  
   267. 
     
   268. 
   for (int i = 0; i < IMAGE_COUNT; i++) { 
  
   269. 
   ImageView imageView = imageViewsList.get(i); 
  
   270. 
   Drawable drawable = imageView.getDrawable(); 
  
   271. 
   if (drawable != null) { 
  
   272. 
   //解除drawable對view的引用 
  
   273. 
   drawable.setCallback(null); 
  
   274. 
   } 
  
   275. 
   } 
  
   276. 
   } 
  
   277. 
     
   278. 
   }

如何引用上面自定義的輪播圖效果視圖View呢？其實很引用普通的View相似，實現以下：佈局

 
   1. 
   <com.czm.customview.SlideShowView 
  
   2. 
   android:id="@+id/slideshowView" 
  
   3. 
   android:layout_width="335dp" 
  
   4. 
   android:layout_height="120dp" 
  
   5. 
   android:layout_centerHorizontal="true" 
  
   6. 
   /> 
  
   轉自：http://www.it165.net/pro/html/201406/16227.html