編輯：關於Android編程
一些新手總是很頭疼怎麼獲取網絡圖片的url之後讓它像一些廣告那樣輪播起來，點擊圖片之後跳轉到指定網頁。效果如下
在布局引用自定義控件
MainActivity.java
public class MainActivity extends Activity {
private String[] imageUrls = new String[]{
"http://d.hiphotos.baidu.com/image/pic/item/9f2f070828381f30b2bd028fac014c086e06f074.jpg",
"http://h.hiphotos.baidu.com/image/pic/item/2934349b033b5bb55e73afd833d3d539b600bc74.jpg",
"http://b.hiphotos.baidu.com/image/pic/item/ac345982b2b7d0a2bdfa8bbbceef76094b369ae1.jpg",
"http://g.hiphotos.baidu.com/image/pic/item/2e2eb9389b504fc213023f23e0dde71190ef6db3.jpg" } ;
private String[] imageUris = new String[]{
"http://www.baidu.com",
"http://www.sina.com.cn",
"http://www.taobao.com",
"http://www.tudou.com" };
private List> imageList = new ArrayList>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
for (int i = 0; i < 4; i++) {
Map image_uri = new HashMap();
image_uri.put("imageUrls", imageUrls[i]);
image_uri.put("imageUris", imageUris[i]);
imageList.add(image_uri);
}
SlideShowView view = (SlideShowView) findViewById(R.id.slideshowView);
view.setImageUrls(imageList);
}
}
自定義輪播的詳細實現
public class SlideShowView extends FrameLayout implements OnClickListener{
// 使用universal-image-loader插件讀取網絡圖片，需要工程導入universal-image-loader-1.8.6-with-sources.jar
private ImageLoader imageLoader = ImageLoader.getInstance();
//輪播圖圖片數量
private final static int IMAGE_COUNT = 5;
//自動輪播的時間間隔
private final static int TIME_INTERVAL = 5;
//自動輪播啟用開關
private final static boolean isAutoPlay = true;
//自定義輪播圖的資源
private List> imageUrls;
//放輪播圖片的ImageView 的list
private List imageViewsList;
//放圓點的View的list
private List dotViewsList;
private ViewPager viewPager;
//當前輪播頁
private int currentItem = 0;
//定時任務
private ScheduledExecutorService scheduledExecutorService;
private Context context;
//Handler
private Handler handler = new Handler(){
@Override
public void handleMessage(Message msg) {
// TODO Auto-generated method stub
super.handleMessage(msg);
viewPager.setCurrentItem(currentItem);
}
};
public SlideShowView(Context context) {
this(context,null);
// TODO Auto-generated constructor stub
}
public SlideShowView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
// TODO Auto-generated constructor stub
}
public SlideShowView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
this.context = context;
initImageLoader(context);
if(isAutoPlay){
startPlay();
}
}
/**
* 開始輪播圖切換
*/
private void startPlay(){
scheduledExecutorService = Executors.newSingleThreadScheduledExecutor();
scheduledExecutorService.scheduleAtFixedRate(new SlideShowTask(), 1, 4, TimeUnit.SECONDS);
}
/**
* 停止輪播圖切換
*/
private void stopPlay(){
scheduledExecutorService.shutdown();
}
/**
* 初始化相關Data
*/
private void initData(){
imageViewsList = new ArrayList();
dotViewsList = new ArrayList();
initUI(context);
}
public void setImageUrls(List> imageList){
this.imageUrls = imageList;
initData();
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent = null;
Bundle bundle = null;
switch (v.getId()) {
case 0:
intent = new Intent(context,WebViewActivity.class);
bundle = new Bundle();
bundle.putString("url", imageUrls.get(0).get("imageUris"));
intent.putExtras(bundle);
context.startActivity(intent);
break;
case 1:
intent = new Intent(context,WebViewActivity.class);
bundle = new Bundle();
bundle.putString("url", imageUrls.get(1).get("imageUris"));
intent.putExtras(bundle);
context.startActivity(intent);
break;
case 2:
intent = new Intent(context,WebViewActivity.class);
bundle = new Bundle();
bundle.putString("url", imageUrls.get(2).get("imageUris"));
intent.putExtras(bundle);
context.startActivity(intent);
break;
case 3:
intent = new Intent(context,WebViewActivity.class);
bundle = new Bundle();
bundle.putString("url", imageUrls.get(3).get("imageUris"));
intent.putExtras(bundle);
context.startActivity(intent);
break;
}
}
/**
* 初始化Views等UI
*/
private void initUI(Context context){
if(imageUrls == null || imageUrls.size() == 0)
return;
LayoutInflater.from(context).inflate(R.layout.layout_slideshow, this, true);
LinearLayout dotLayout = (LinearLayout)findViewById(R.id.dotLayout);
dotLayout.removeAllViews();
// 熱點個數與圖片特殊相等
for (int i = 0; i < imageUrls.size(); i++) {
ImageView view = new ImageView(context);
view.setId(i);
view.setTag(imageUrls.get(i).get("imageUrls"));
if(i==0)//給一個默認圖
view.setBackgroundResource(R.drawable.detail_p1);
view.setScaleType(ScaleType.FIT_XY);
view.setOnClickListener(this);
imageViewsList.add(view);
ImageView dotView = new ImageView(context);
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);
params.leftMargin = 4;
params.rightMargin = 4;
dotLayout.addView(dotView, params);
dotViewsList.add(dotView);
}
viewPager = (ViewPager) findViewById(R.id.viewPager);
viewPager.setFocusable(true);
viewPager.setAdapter(new MyPagerAdapter());
viewPager.setOnPageChangeListener(new MyPageChangeListener());
}
/**
* 填充ViewPager的頁面適配器
*
*/
private class MyPagerAdapter extends PagerAdapter{
@Override
public void destroyItem(View container, int position, Object object) {
// TODO Auto-generated method stub
//((ViewPag.er)container).removeView((View)object);
((ViewPager)container).removeView(imageViewsList.get(position));
}
@Override
public Object instantiateItem(View container, int position) {
ImageView imageView = imageViewsList.get(position);
imageLoader.displayImage(imageView.getTag() + "", imageView);
((ViewPager)container).addView(imageViewsList.get(position));
return imageViewsList.get(position);
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return imageViewsList.size();
}
@Override
public boolean isViewFromObject(View arg0, Object arg1) {
// TODO Auto-generated method stub
return arg0 == arg1;
}
@Override
public void restoreState(Parcelable arg0, ClassLoader arg1) {
// TODO Auto-generated method stub
}
@Override
public Parcelable saveState() {
// TODO Auto-generated method stub
return null;
}
@Override
public void startUpdate(View arg0) {
// TODO Auto-generated method stub
}
@Override
public void finishUpdate(View arg0) {
// TODO Auto-generated method stub
}
}
/**
* ViewPager的監聽器
* 當ViewPager中頁面的狀態發生改變時調用
*
*/
private class MyPageChangeListener implements OnPageChangeListener{
boolean isAutoPlay = false;
@Override
public void onPageScrollStateChanged(int arg0) {
// TODO Auto-generated method stub
switch (arg0) {
case 1:// 手勢滑動，空閒中
isAutoPlay = false;
break;
case 2:// 界面切換中
isAutoPlay = true;
break;
case 0:// 滑動結束，即切換完畢或者加載完畢
// 當前為最後一張，此時從右向左滑，則切換到第一張
if (viewPager.getCurrentItem() == viewPager.getAdapter().getCount() - 1 && !isAutoPlay) {
viewPager.setCurrentItem(0);
}
// 當前為第一張，此時從左向右滑，則切換到最後一張
else if (viewPager.getCurrentItem() == 0 && !isAutoPlay) {
viewPager.setCurrentItem(viewPager.getAdapter().getCount() - 1);
}
break;
}
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
// TODO Auto-generated method stub
}
@Override
public void onPageSelected(int pos) {
// TODO Auto-generated method stub
currentItem = pos;
for(int i=0;i < dotViewsList.size();i++){
if(i == pos){
((View)dotViewsList.get(pos)).setBackgroundResource(R.drawable.compose_guide_check_box_number);
}else {
((View)dotViewsList.get(i)).setBackgroundResource(R.drawable.compose_guide_check_box_default);
}
}
}
}
/**
*執行輪播圖切換任務
*/
private class SlideShowTask implements Runnable{
@Override
public void run() {
// TODO Auto-generated method stub
synchronized (viewPager) {
currentItem = (currentItem+1)%imageViewsList.size();
handler.obtainMessage().sendToTarget();
}
}
}
/**
* 銷毀ImageView資源，回收內存
*/
private void destoryBitmaps() {
for (int i = 0; i < IMAGE_COUNT; i++) {
ImageView imageView = imageViewsList.get(i);
Drawable drawable = imageView.getDrawable();
if (drawable != null) {
//解除drawable對view的引用
drawable.setCallback(null);
}
}
}
public static void initImageLoader(Context context) {
ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(context)
.threadPriority(Thread.NORM_PRIORITY - 2)
.denyCacheImageMultipleSizesInMemory()
.discCacheFileNameGenerator(new Md5FileNameGenerator())
.tasksProcessingOrder(QueueProcessingType.LIFO)
.writeDebugLogs()
.build();
ImageLoader.getInstance().init(config);
}
}
帶指示器的布局
點擊廣告跳轉的web
public class WebViewActivity extends Activity{
private WebView mWebView;
private TextView mTitle;
private ImageButton mBackBtn;
private Bundle mBundle;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
setContentView(R.layout.activity_web);
super.onCreate(savedInstanceState);
mBundle = getIntent().getExtras();
initView();
}
public void initView() {
// TODO Auto-generated method stub
mWebView = (WebView) findViewById(R.id.web_webview);
mWebView.loadUrl(mBundle.getString("url"));
mWebView.requestFocusFromTouch();
mWebView.getSettings().setCacheMode(WebSettings.LOAD_CACHE_ELSE_NETWORK);
/**覆蓋調用系統或自帶浏覽器行為打開網頁*/
mWebView.setWebViewClient(new WebViewClient(){
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
// TODO Auto-generated method stub
view.loadUrl(url);
return true;
}
});
/**判斷加載過程*/
mWebView.setWebChromeClient(new WebChromeClient() {
@Override
public void onProgressChanged(WebView view, int newProgress) {
// TODO Auto-generated method stub
if (newProgress == 100) {
// 網頁加載完成
} else {
// 加載中
}
}
});
initListener();
}
public void initListener() {
// TODO Auto-generated method stub
/**加載javascript*/
// WebSettings mWebSetting = mWebView.getSettings();
// mWebSetting.setJavaScriptEnabled(true);
// mWebView.addJavascriptInterface(new Object() {
// public void clickOnAndroid() {
// new Handler().post(new Runnable() {
// public void run() {
// mWebView.loadUrl("javascript：wave()");
// }
// });
// }
// }, "demo");
/**打開頁面時， 自適應屏幕*/
WebSettings webSettings = mWebView .getSettings();
webSettings.setUseWideViewPort(true);//設置此屬性，可任意比例縮放
webSettings.setLoadWithOverviewMode(true);
/**便頁面支持縮放*/
webSettings.setJavaScriptEnabled(true);
webSettings.setBuiltInZoomControls(true);
webSettings.setSupportZoom(true);
}
}
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