Android Imageloader未在实际设备上加载图像
我正在使用ImageLoader类从url加载图像,并将其显示在 列表视图。但是这个ImageLoader是在模拟器上加载图像的,当我 在真实设备上运行我的应用程序,它不会加载任何图像。(只显示 默认图像) 请告诉我,为了让ImageLoader类在真正的设备上工作,我必须对它做些什么 ImageLoader类:Android Imageloader未在实际设备上加载图像,android,Android,我正在使用ImageLoader类从url加载图像,并将其显示在 列表视图。但是这个ImageLoader是在模拟器上加载图像的,当我 在真实设备上运行我的应用程序,它不会加载任何图像。(只显示 默认图像) 请告诉我,为了让ImageLoader类在真正的设备上工作,我必须对它做些什么 ImageLoader类: 公共类ImageLoader{ MemoryCache MemoryCache=新的MemoryCache(); 文件缓存文件缓存; 私有地图图像视图=集合 .synchronized
公共类ImageLoader{
MemoryCache MemoryCache=新的MemoryCache();
文件缓存文件缓存;
私有地图图像视图=集合
.synchronizedMap(新WeakHashMap());
执行服务执行服务;
//在UI线程中显示图像的处理程序
Handler=newhandler();
公共图像加载器(上下文){
fileCache=新的fileCache(上下文);
executorService=Executors.newFixedThreadPool(5);
}
最终int stub_id=R.drawable.products;
public void DisplayImage(字符串url,ImageView){
put(imageView,url);
位图位图=memoryCache.get(url);
if(位图!=null)
设置图像位图(位图);
否则{
队列照片(url、imageView);
setImageResource(存根id);
}
}
私有void队列照片(字符串url,ImageView){
PhotoToLoad p=新的PhotoToLoad(url,imageView);
executorService.submit(新的PhotoLoader(p));
}
私有位图getBitmap(字符串url){
文件f=fileCache.getFile(url);
位图b=解码文件(f);
如果(b!=null)
返回b;
//从Internet下载图像
试一试{
位图=空;
URL imageUrl=新URL(URL);
HttpURLConnection conn=(HttpURLConnection)imageUrl
.openConnection();
连接设置连接超时(30000);
连接设置读取超时(30000);
conn.setInstanceFollowRedirects(真);
InputStream is=conn.getInputStream();
OutputStream os=新文件OutputStream(f);
Utils.CopyStream(is,os);
os.close();
连接断开();
位图=解码文件(f);
返回位图;
}捕获(可丢弃的ex){
例如printStackTrace();
if(ex instanceof OutOfMemoryError)
memoryCache.clear();
返回null;
}
}
//对图像进行解码和缩放以减少内存消耗
私有位图解码文件(文件f){
试一试{
//解码图像大小
BitmapFactory.Options o=新的BitmapFactory.Options();
o、 inJustDecodeBounds=true;
FileInputStream stream1=新的FileInputStream(f);
解码流(stream1,null,o);
stream1.close();
//找到正确的刻度值。它应该是2的幂。
//推荐尺寸512
所需的最终int_尺寸=70;
内部宽度=o.向外宽度,高度=o.向外高度;
int标度=1;
while(true){
如果(宽度\u tmp/2<要求的\u尺寸
||高度(tmp/2<所需尺寸)
打破
宽度_tmp/=2;
高度_tmp/=2;
比例*=2;
}
//用inSampleSize解码
BitmapFactory.Options o2=新的BitmapFactory.Options();
o2.inSampleSize=刻度;
FileInputStream stream2=新的FileInputStream(f);
位图位图=BitmapFactory.decodeStream(stream2,null,o2);
stream2.close();
返回位图;
}catch(filenotfounde异常){
}捕获(IOE异常){
e、 printStackTrace();
}
返回null;
}
//队列的任务
私有类光电负载{
公共字符串url;
公共影像视图;
公共PhotoToLoad(字符串u,图像视图i){
url=u;
imageView=i;
}
}
类photoloader实现可运行{
光电负载光电负载;
PhotoLoader(PhotoToLoad PhotoToLoad){
this.photoToLoad=photoToLoad;
}
@凌驾
公开募捐{
试一试{
if(图像视图重用(光电加载))
返回;
位图bmp=getBitmap(photoLoad.url);
memoryCache.put(photoload.url,bmp);
if(图像视图重用(光电加载))
返回;
BitmapDisplayer bd=新的BitmapDisplayer(bmp,photoToLoad);
邮政署署长(屋宇署);
}捕获(可丢弃){
th.printStackTrace();
}
}
}
布尔图像视图(PhotoToLoad PhotoToLoad){
String tag=imageViews.get(photoload.imageView);
if(tag==null | |!tag.equals(photoload.url))
返回true;
返回false;
}
//用于在UI线程中显示位图
类BitmapDisplayer实现可运行{
位图;
光电负载光电负载;
公共位图显示器(位图b、PhotoToLoad p){
位图=b;
光电负载=p;
}
公开募捐{
if(图像视图重用(光电加载))
返回;
if(位图!=null)
photoToLoad.imageView.setImageBitmap(位图);
其他的
photoToLoad.imageView.setImageResource(存根id);
}
}
公共void clearCache(){
memoryCache.clear();
fileCache.clear();
}
}
我的GalleryTab类:--
公共类GalleryTab扩展片段{
GridView;
进程对话框;
GridViewAdapter;
公共列表phonearraylist=null;
视图;
私有WeakReference异步任务weakref;
公共街
public class ImageLoader {
MemoryCache memoryCache = new MemoryCache();
FileCache fileCache;
private Map<ImageView, String> imageViews = Collections
.synchronizedMap(new WeakHashMap<ImageView, String>());
ExecutorService executorService;
// Handler to display images in UI thread
Handler handler = new Handler();
public ImageLoader(Context context) {
fileCache = new FileCache(context);
executorService = Executors.newFixedThreadPool(5);
}
final int stub_id = R.drawable.products;
public void DisplayImage(String url, ImageView imageView) {
imageViews.put(imageView, url);
Bitmap bitmap = memoryCache.get(url);
if (bitmap != null)
imageView.setImageBitmap(bitmap);
else {
queuePhoto(url, imageView);
imageView.setImageResource(stub_id);
}
}
private void queuePhoto(String url, ImageView imageView) {
PhotoToLoad p = new PhotoToLoad(url, imageView);
executorService.submit(new PhotosLoader(p));
}
private Bitmap getBitmap(String url) {
File f = fileCache.getFile(url);
Bitmap b = decodeFile(f);
if (b != null)
return b;
// Download Images from the Internet
try {
Bitmap bitmap = null;
URL imageUrl = new URL(url);
HttpURLConnection conn = (HttpURLConnection) imageUrl
.openConnection();
conn.setConnectTimeout(30000);
conn.setReadTimeout(30000);
conn.setInstanceFollowRedirects(true);
InputStream is = conn.getInputStream();
OutputStream os = new FileOutputStream(f);
Utils.CopyStream(is, os);
os.close();
conn.disconnect();
bitmap = decodeFile(f);
return bitmap;
} catch (Throwable ex) {
ex.printStackTrace();
if (ex instanceof OutOfMemoryError)
memoryCache.clear();
return null;
}
}
// Decodes image and scales it to reduce memory consumption
private Bitmap decodeFile(File f) {
try {
// Decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
FileInputStream stream1 = new FileInputStream(f);
BitmapFactory.decodeStream(stream1, null, o);
stream1.close();
// Find the correct scale value. It should be the power of 2.
// Recommended Size 512
final int REQUIRED_SIZE = 70;
int width_tmp = o.outWidth, height_tmp = o.outHeight;
int scale = 1;
while (true) {
if (width_tmp / 2 < REQUIRED_SIZE
|| height_tmp / 2 < REQUIRED_SIZE)
break;
width_tmp /= 2;
height_tmp /= 2;
scale *= 2;
}
// Decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = scale;
FileInputStream stream2 = new FileInputStream(f);
Bitmap bitmap = BitmapFactory.decodeStream(stream2, null, o2);
stream2.close();
return bitmap;
} catch (FileNotFoundException e) {
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
// Task for the queue
private class PhotoToLoad {
public String url;
public ImageView imageView;
public PhotoToLoad(String u, ImageView i) {
url = u;
imageView = i;
}
}
class PhotosLoader implements Runnable {
PhotoToLoad photoToLoad;
PhotosLoader(PhotoToLoad photoToLoad) {
this.photoToLoad = photoToLoad;
}
@Override
public void run() {
try {
if (imageViewReused(photoToLoad))
return;
Bitmap bmp = getBitmap(photoToLoad.url);
memoryCache.put(photoToLoad.url, bmp);
if (imageViewReused(photoToLoad))
return;
BitmapDisplayer bd = new BitmapDisplayer(bmp, photoToLoad);
handler.post(bd);
} catch (Throwable th) {
th.printStackTrace();
}
}
}
boolean imageViewReused(PhotoToLoad photoToLoad) {
String tag = imageViews.get(photoToLoad.imageView);
if (tag == null || !tag.equals(photoToLoad.url))
return true;
return false;
}
// Used to display bitmap in the UI thread
class BitmapDisplayer implements Runnable {
Bitmap bitmap;
PhotoToLoad photoToLoad;
public BitmapDisplayer(Bitmap b, PhotoToLoad p) {
bitmap = b;
photoToLoad = p;
}
public void run() {
if (imageViewReused(photoToLoad))
return;
if (bitmap != null)
photoToLoad.imageView.setImageBitmap(bitmap);
else
photoToLoad.imageView.setImageResource(stub_id);
}
}
public void clearCache() {
memoryCache.clear();
fileCache.clear();
}
}
public class GalleryTab extends Fragment {
GridView gridview;
ProgressDialog mProgressDialog;
GridViewAdapter adapter;
public List<GalleryList> phonearraylist = null;
View view;
private WeakReference<RemoteDataTask> asyncTaskWeakRef;
public static Fragment newInstance(Context context) {
GalleryTab f = new GalleryTab();
return f;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
view = inflater.inflate(R.layout.activity_gallery_tab, null);
gridview = (GridView) view.findViewById(R.id.gridview);
setRetainInstance(true);
startNewAsyncTask();
// new RemoteDataTask(this).execute();
return view;
}
// RemoteDataTask AsyncTask
private class RemoteDataTask extends AsyncTask<Void, Void, Void> {
private WeakReference<GalleryTab> fragmentWeakRef;
private RemoteDataTask(GalleryTab gallerytab) {
this.fragmentWeakRef = new WeakReference<GalleryTab>(gallerytab);
}
@Override
protected void onPreExecute() {
super.onPreExecute();
mProgressDialog = new ProgressDialog(getActivity());
mProgressDialog.setTitle("Gallery");
mProgressDialog.setMessage("Loading...");
mProgressDialog.setIndeterminate(false);
mProgressDialog.show();
}
@Override
protected Void doInBackground(Void... params) {
// Create the array
phonearraylist = new ArrayList<GalleryList>();
try {
for (int i = 0; i <= 6; i++) {
GalleryList map = new GalleryList();
map.setGallery("http://oi39.tinypic.com/21oydxs.jpg");
// System.out.println("PRINT!!!!-- "+ i);
phonearraylist.add(map);
}
} catch (ParseException e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// if (this.fragmentWeakRef.get() != null) {
adapter = new GridViewAdapter(getActivity(), phonearraylist);
// System.out.println("PRINT SIZE -- "+ phonearraylist.size());
gridview.setAdapter(adapter);
mProgressDialog.dismiss();
// }
}
}
private void startNewAsyncTask() {
RemoteDataTask asyncTask = new RemoteDataTask(this);
this.asyncTaskWeakRef = new WeakReference<RemoteDataTask>(asyncTask);
asyncTask.execute();
}
}
public class GridViewAdapter extends BaseAdapter {
// Declare Variables
Context context;
LayoutInflater inflater;
ImageLoader imageLoader;
private List<GalleryList> galleryArraylist = null;
private ArrayList<GalleryList> arraylist;
public GridViewAdapter(Context context, List<GalleryList> phonearraylist) {
this.context = context;
this.galleryArraylist = phonearraylist;
inflater = LayoutInflater.from(context);
this.arraylist = new ArrayList<GalleryList>();
this.arraylist.addAll(phonearraylist);
imageLoader = new ImageLoader(context);
}
public class ViewHolder {
ImageView phone;
}
@Override
public int getCount() {
return galleryArraylist.size();
}
@Override
public Object getItem(int position) {
return galleryArraylist.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
public View getView(final int position, View view, ViewGroup parent) {
final ViewHolder holder;
if (view == null) {
holder = new ViewHolder();
view = inflater.inflate(R.layout.gridview_item, null);
// Locate the ImageView in gridview_item.xml
holder.phone = (ImageView) view.findViewById(R.id.phone);
view.setTag(holder);
} else {
holder = (ViewHolder) view.getTag();
}
// Set the results into ImageView
imageLoader.DisplayImage(galleryArraylist.get(position).getGallery(),
holder.phone);
// Listen for GridView Item Click
view.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// Send single item click data to SingleItemView Class
Intent intent = new Intent(context, SingleItemView.class);
// Pass all data phone
intent.putExtra("gallery",
(galleryArraylist.get(position).getGallery()));
// Start SingleItemView Class
context.startActivity(intent);
}
});
return view;
}
}
photoToLoad.imageView.setImageBitmap(stub_id);
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />