I am new to Android. I have a trouble about using AsyncTask.
I am trying to create a picture gallery. In my gallery there are small size pictures and when you click on one of them, big size of that picture is shown in the below ImageView. I used two different AsyncTask class. One of them is fetching the small size pictures from the host, another one is fetching the big size pictures from host when you click on one of the pictures in the gallery.
I can load gallery images but when I click on one of gallery image I can’t display big size images in ImageView.
If you help me or for any advice, i will appreciate…
My code is:
public class GalleryView extends Activity{
String[] smallpicsURL ={
"http://egtxxxxx.com/jImages/antartica1.jpg",
"http://egtxxxxx.com/jImages/antartica2.jpg",
"http://egtxxxxx.com/jImages/antartica3.jpg",
"http://egtxxxxx.com/jImages/antartica4.jpg",
"http://egtxxxxx.com/jImages/antartica5.jpg",
"http://egtxxxxx.com/jImages/antartica6.jpg",
"http://egtxxxxx.com/jImages/antartica7.jpg",
"http://egtxxxxx.com/jImages/antartica8.jpg",
"http://egtxxxxx.com/jImages/antartica9.jpg",
"http://egtxxxxx.com/jImages/antartica10.jpg"
};
String[] bigpicsURL ={
"http://egtxxxxx.com/jImages/b_antartica1.jpg",
"http://egtxxxxx.com/jImages/b_antartica2.jpg",
"http://egtxxxxx.com/jImages/b_antartica3.jpg",
"http://egtxxxxx.com/jImages/b_antartica4.jpg",
"http://egtxxxxx.com/jImages/b_antartica5.jpg",
"http://egtxxxxx.com/jImages/b_antartica6.jpg",
"http://egtxxxxx.com/jImages/b_antartica7.jpg",
"http://egtxxxxx.com/jImages/b_antartica8.jpg",
"http://egtxxxxx.com/jImages/b_antartica9.jpg",
"http://egtxxxxx.com/jImages/b_antartica10.jpg"
};
Bitmap pics[];
Bitmap bigPic;
ImageView imageView;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.gallery);
Gallery ga = (Gallery)findViewById(R.id.galleryKBU);
pics=new Bitmap[smallpicsURL.length];
new FetchSmallBitmap().execute();
ga.setAdapter(new ImageAdapter(this));
try {
Thread.sleep(700);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
imageView = (ImageView)findViewById(R.id.ivKBU);
ga.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
Toast.makeText(getBaseContext(),"Çağdaş Eğitim Yuvası", Toast.LENGTH_SHORT).show();
new FetchBigBitmap().execute(arg2);
//imageView.setImageBitmap(bigPic);
}
});
}
private Bitmap downloadPictures(int i) {
String urlStr=smallpicsURL[i];
try {
URL url = new URL(urlStr);
final URLConnection conn = url.openConnection();
conn.connect();
final BufferedInputStream bis = new BufferedInputStream(conn.getInputStream());
final Bitmap bm = BitmapFactory.decodeStream(bis);
bis.close();
return bm;
} catch (IOException e) {
Log.d("DEBUGTAG",". Resim indirmede hata...");
}
return null;
}
private Bitmap downloadBigPictures(int i) {
String urlStr=bigpicsURL[i];
try {
URL url = new URL(urlStr);
final URLConnection conn = url.openConnection();
conn.connect();
final BufferedInputStream bis = new BufferedInputStream(conn.getInputStream());
final Bitmap bm = BitmapFactory.decodeStream(bis);
bis.close();
return bm;
} catch (IOException e) {
Log.d("DEBUGTAG",". Resim indirmede hata...");
}
return null;
}
private class FetchSmallBitmap extends AsyncTask<Void, Integer, Bitmap[]> {
private ProgressDialog dialog = new ProgressDialog(GalleryView.this);
protected void onPreExecute(){
dialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
dialog.setMax(100);
dialog.setMessage("Resimler yükleniyor");
dialog.show();
}
@Override
protected Bitmap[] doInBackground (Void ...params) {
for(int i=0;i<10;i++){
pics[i]=downloadPictures(i);
publishProgress(10);
}
return pics;
}
protected void onProgressUpdate(Integer ...progress){
dialog.incrementProgressBy(progress[0]);
}
protected void onPostExecute(Bitmap[] mbitmap) {
dialog.dismiss();
}
}
public class ImageAdapter extends BaseAdapter {
private Context ctx;
int imageBackground;
public ImageAdapter(Context c) {
ctx = c;
TypedArray ta = obtainStyledAttributes(R.styleable.gallery_KBU);
imageBackground = ta.getResourceId(R.styleable.gallery_KBU_android_galleryItemBackground, 1);
ta.recycle();
}
public int getCount() {
return pics.length;
}
public Object getItem(int arg0) {
return arg0;
}
public long getItemId(int arg0) {
return arg0;
}
public View getView(int arg0, View arg1, ViewGroup arg2) {
ImageView iv = new ImageView(ctx);
iv.setImageBitmap(pics[arg0]);
iv.setScaleType(ImageView.ScaleType.FIT_XY);
iv.setLayoutParams(new Gallery.LayoutParams(150,120));
iv.setBackgroundResource(imageBackground);
return iv;
}
}
private class FetchBigBitmap extends AsyncTask<Integer, Integer, Bitmap> {
private ProgressDialog dialog = new ProgressDialog(GalleryView.this);
protected void onPreExecute(){
dialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
dialog.setMax(100);
dialog.setMessage("Resimler yükleniyor");
dialog.show();
}
@Override
protected Bitmap doInBackground (Integer ...params) {
imageView.setImageBitmap(downloadBigPictures(params[0]));
return null;
}
protected void onProgressUpdate(Integer ...progress){
dialog.incrementProgressBy(progress[0]);
}
protected void onPostExecute(Bitmap x) {
dialog.dismiss();
}
}
}
I get an error message like this:
08-18 15:23:11.477: E/AndroidRuntime(15005): FATAL EXCEPTION: AsyncTask #2
08-18 15:23:11.477: E/AndroidRuntime(15005): java.lang.RuntimeException: An error occured while executing doInBackground()
08-18 15:23:11.477: E/AndroidRuntime(15005): at android.os.AsyncTask$3.done(AsyncTask.java:200)
08-18 15:23:11.477: E/AndroidRuntime(15005): at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
08-18 15:23:11.477: E/AndroidRuntime(15005): at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
08-18 15:23:11.477: E/AndroidRuntime(15005): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
08-18 15:23:11.477: E/AndroidRuntime(15005): at java.util.concurrent.FutureTask.run(FutureTask.java:137)
08-18 15:23:11.477: E/AndroidRuntime(15005): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1068)
08-18 15:23:11.477: E/AndroidRuntime(15005): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:561)
08-18 15:23:11.477: E/AndroidRuntime(15005): at java.lang.Thread.run(Thread.java:1096)
08-18 15:23:11.477: E/AndroidRuntime(15005): Caused by: android.view.ViewRoot$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
08-18 15:23:11.477: E/AndroidRuntime(15005): at android.view.ViewRoot.checkThread(ViewRoot.java:2812)
08-18 15:23:11.477: E/AndroidRuntime(15005): at android.view.ViewRoot.requestLayout(ViewRoot.java:594)
08-18 15:23:11.477: E/AndroidRuntime(15005): at android.view.View.requestLayout(View.java:8125)
08-18 15:23:11.477: E/AndroidRuntime(15005): at android.view.View.requestLayout(View.java:8125)
08-18 15:23:11.477: E/AndroidRuntime(15005): at android.view.View.requestLayout(View.java:8125)
08-18 15:23:11.477: E/AndroidRuntime(15005): at android.view.View.requestLayout(View.java:8125)
08-18 15:23:11.477: E/AndroidRuntime(15005): at android.view.View.requestLayout(View.java:8125)
08-18 15:23:11.477: E/AndroidRuntime(15005): at android.widget.ImageView.setImageDrawable(ImageView.java:310)
08-18 15:23:11.477: E/AndroidRuntime(15005): at android.widget.ImageView.setImageBitmap(ImageView.java:324)
08-18 15:23:11.477: E/AndroidRuntime(15005): at com.kbu.bilgisistemi.GalleryView$FetchBigBitmap.doInBackground(GalleryView.java:258)
08-18 15:23:11.477: E/AndroidRuntime(15005): at com.kbu.bilgisistemi.GalleryView$FetchBigBitmap.doInBackground(GalleryView.java:1)
08-18 15:23:11.477: E/AndroidRuntime(15005): at android.os.AsyncTask$2.call(AsyncTask.java:185)
08-18 15:23:11.477: E/AndroidRuntime(15005): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
08-18 15:23:11.477: E/AndroidRuntime(15005): ... 4 more
08-18 15:23:11.687: E/WindowManager(15005): Activity com.kbu.bilgisistemi.GalleryView has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@4a514158 that was originally added here
08-18 15:23:11.687: E/WindowManager(15005): android.view.WindowLeaked: Activity com.kbu.bilgisistemi.GalleryView has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@4a514158 that was originally added here
08-18 15:23:11.687: E/WindowManager(15005): at android.view.ViewRoot.<init>(ViewRoot.java:247)
08-18 15:23:11.687: E/WindowManager(15005): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:148)
08-18 15:23:11.687: E/WindowManager(15005): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)
08-18 15:23:11.687: E/WindowManager(15005): at android.view.Window$LocalWindowManager.addView(Window.java:424)
08-18 15:23:11.687: E/WindowManager(15005): at android.app.Dialog.show(Dialog.java:241)
08-18 15:23:11.687: E/WindowManager(15005): at com.kbu.bilgisistemi.GalleryView$FetchBigBitmap.onPreExecute(GalleryView.java:253)
08-18 15:23:11.687: E/WindowManager(15005): at android.os.AsyncTask.execute(AsyncTask.java:391)
08-18 15:23:11.687: E/WindowManager(15005): at com.kbu.bilgisistemi.GalleryView$1.onItemClick(GalleryView.java:102)
08-18 15:23:11.687: E/WindowManager(15005): at android.widget.AdapterView.performItemClick(AdapterView.java:284)
08-18 15:23:11.687: E/WindowManager(15005): at android.widget.Gallery.onSingleTapUp(Gallery.java:864)
08-18 15:23:11.687: E/WindowManager(15005): at android.view.GestureDetector.onTouchEvent(GestureDetector.java:557)
08-18 15:23:11.687: E/WindowManager(15005): at android.widget.Gallery.onTouchEvent(Gallery.java:839)
08-18 15:23:11.687: E/WindowManager(15005): at android.view.View.dispatchTouchEvent(View.java:3766)
08-18 15:23:11.687: E/WindowManager(15005): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:897)
08-18 15:23:11.687: E/WindowManager(15005): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:936)
08-18 15:23:11.687: E/WindowManager(15005): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:936)
08-18 15:23:11.687: E/WindowManager(15005): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:936)
08-18 15:23:11.687: E/WindowManager(15005): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:936)
08-18 15:23:11.687: E/WindowManager(15005): at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1731)
08-18 15:23:11.687: E/WindowManager(15005): at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1120)
08-18 15:23:11.687: E/WindowManager(15005): at android.app.Activity.dispatchTouchEvent(Activity.java:2086)
08-18 15:23:11.687: E/WindowManager(15005): at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1715)
08-18 15:23:11.687: E/WindowManager(15005): at android.view.ViewRoot.handleMessage(ViewRoot.java:1787)
08-18 15:23:11.687: E/WindowManager(15005): at android.os.Handler.dispatchMessage(Handler.java:99)
08-18 15:23:11.687: E/WindowManager(15005): at android.os.Looper.loop(Looper.java:123)
08-18 15:23:11.687: E/WindowManager(15005): at android.app.ActivityThread.main(ActivityThread.java:4633)
08-18 15:23:11.687: E/WindowManager(15005): at java.lang.reflect.Method.invokeNative(Native Method)
08-18 15:23:11.687: E/WindowManager(15005): at java.lang.reflect.Method.invoke(Method.java:521)
08-18 15:23:11.687: E/WindowManager(15005): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858)
08-18 15:23:11.687: E/WindowManager(15005): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
08-18 15:23:11.687: E/WindowManager(15005): at dalvik.system.NativeStart.main(Native Method)
You cannot do below operation on Non-UI thread. You are doing a Ui operation in doinbackground.
Move above line to OnpostExecute.
You dont need an Asynctask just to set the image