I am a learner and have been working on a home visitor app to get image from a URL of the visitor. Using the following code, which I found online, I was able to load image by adding an intent before the screen and adding a button on the screen saying "See Visitor Image" but now I want that my image should load as soon as the app launches. What changes could I make to do that? Thanks for your help.
OnClickListener getImageBtnOnClick = new OnClickListener() {
public void onClick(View view) {
Context context = view.getContext();
Editable ed = inputUrl.getText();
Drawable image = ImageOperations(context,ed.toString(),"image.jpg");
ImageView imgView = new ImageView(context);
imgView = (ImageView)findViewById(R.id.image1);
imgView.setImageDrawable(image);
}
};
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.main);
inputUrl = ((EditText)findViewById(R.id.imageUrl));
inputUrl.setSingleLine();
inputUrl.setTextSize(11);
Button getImageButton = (Button)findViewById(R.id.getImageButton);
getImageButton.setOnClickListener(getImageBtnOnClick);
}
private Drawable ImageOperations(Context ctx, String url, String saveFilename) {
try {
InputStream is = (InputStream) this.fetch(url);
Drawable d = Drawable.createFromStream(is, "src");
return d;
} catch (MalformedURLException e) {
e.printStackTrace();
return null;
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
public Object fetch(String address) throws MalformedURLException,IOException {
URL url = new URL(address);
Object content = url.getContent();
return content;
}
You can make use of SmartImageView, it is a drop-in replacement for Android’s standard ImageView which additionally allows images to be loaded from URLs or the user’s contact address book. Images are cached to memory and to disk for super fast loading.
https://github.com/loopj/android-smart-image-view
Or on OnResume of ur activity start downloading the image form the url as u r doing now in the click listener of button in a separate thread to avoid blocking main UI thread. Once you completed the download you can update the image view using handler from the worker thread.
You can make use of async task also instead of creating your own thread and handler to update UI. for more infor about async task refer following link http://www.vogella.com/articles/AndroidPerformance/article.html
Related
This question already has answers here:
Android - How to download an image and use it as new resource?
(4 answers)
Closed 9 years ago.
I have got a demo image link :
http://madhabpurps.org/wp-content/uploads/2013/04/28-239x300.jpg
I want to set the image in the background of a layout inside the view holder class:
static class ViewHolder {
TextView txtName;
TextView txtCityState;
RelativeLayout rl;
}
holder.txtName.setText(searchArrayList.get(position).getTitle());
holder.txtCityState.setText(searchArrayList.get(position).getDescription());
I have to set the image from the link here, I have tried this line of code but it's showing error.
holder.rl.setBackgroundResource(searchArrayList.get(position).getImage());
I get answer from here change background image of Framelayout via URL
private Drawable ImageOperations(Context ctx, String url, String saveFilename) {
try {
InputStream is = (InputStream) this.fetch(url);
Drawable d = Drawable.createFromStream(is, saveFilename);
return d;
} catch (MalformedURLException e) {
e.printStackTrace();
return null;
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
public Object fetch(String address) throws MalformedURLException,IOException {
URL url = new URL(address);
Object content = url.getContent();
return content;
}
and then you can use it like this
Drawable drw = ImageOperations(this,url,filename)
rl.setBackgroundDrawable(drw);
This should fix. But for general case I recommend another way to solve these problems.
I recommend using a well documented image downloading and caching library. I am using picasso http://square.github.io/picasso/ . Setup it, using library is easy.
Then you can fill an imageview by just writing
Picasso.with(activity)
.load(url)
.fit()
.into(imageView);
use the below code
Bitmap bitmap = BitmapFactory.decodeStream((InputStream)new URL(url).getContent());
Drawable d = new BitmapDrawable(getResources(),bitmap);
rl.setBackgroundDrawable(dr);
I'm not really sure what goes wrong with my code or structure. I wanted to use AsyncTask to download images and display out the progress bar at the mean time. But I tried out a few different way of doing it. It still failed and no idea what's wrong with it. My structure flow is
ContentID is a string array that stores the content ID of the Images.
Primary Issue: It managed to download images from the url and store into the phone, but the downloaded images are all the same image. It should be different images, it's not what I expected.
Secondary Issue: The progress bar pop up while the application downloading images, but the progress bar did not update it's progress. It just remains 0% and dismissed after the download completed.
I wanted to know what causes primary and secodary issue as i mentioned. Please leave a comment or answer if you might know what's wrong with my code. Any help will be appreciated.
if(isSyncSuccess){
SetConstant.IMAGE_EXIST = 1;
pDialog = new ProgressDialog(GalleryScreen.this);
pDialog.setMessage("Downloading file. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setProgress(0);
pDialog.setMax(contentId.length);
pDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
pDialog.setCancelable(true);
if (contentId.length>0){
Log.i(TAG, "contentid.length:" +contentId.length);
for (int i=0;i<contentId.length;i++){
if(helper.databaseChecking(useremail, contentId[i])){
contentdownload = i;
SetConstant.CONTENT_ID = contentId[i];
String URL = SetConstant.URL_DOWNLOAD_CONTENT+contentId[i];
DownloadFile downloadFile = new DownloadFile();
downloadFile.execute(URL);
}
private class DownloadFile extends AsyncTask<String, Integer, String>{
#Override
protected String doInBackground(String... sUrl){
Bitmap bm;
InputStream in;
try{
in = new java.net.URL(sUrl[0]).openStream();
bm = BitmapFactory.decodeStream(new PatchInputStream(in));
File storage = new File(Environment.getExternalStorageDirectory() + File.separator + "/Image/");
Log.i(TAG,"storage:" +storage);
Log.i(TAG,"storage:" +storage.getAbsolutePath());
if(!storage.exists()){
storage.mkdirs();
}
String FileName = "/"+SetConstant.CONTENT_ID+".jpg";
FileOutputStream fos = new FileOutputStream(storage + FileName);
bm.compress(Bitmap.CompressFormat.JPEG, 85, fos);
String filepath = storage + FileName;
File filecheck = new File (filepath);
long fileSize = filecheck.length();
fos.flush();
fos.close();
Log.i(TAG, "bm:" +bm);
Log.i(TAG, "fos:" +fos);
Log.i(TAG, "filesize:" +fileSize);
Log.i(TAG, "filepath:" +filepath);
}
catch(IOException e1){
e1.printStackTrace();
}
return null;
}
#Override
protected void onPreExecute(){
super.onPreExecute();
pDialog.show();
}
#Override
protected void onProgressUpdate(Integer... progress){
super.onProgressUpdate(progress);
pDialog.setProgress(progress[0]);
}
protected void onPostExecute(String result){
super.onPostExecute(result);
pDialog.dismiss();
}
}
Edit
Now the application able to download images according and the progress bar is working as well! But I got another issue is how to return error message when the application failed to complete the download. Currently when the application failed to download it will crash. I believed that I should not run it inside the doInBackground side. But where else can I do the checking? Any idea how to return as an error message and request for the user to retry instead of crashing the application?
You never called onProgressUpdate during your doInBackGround(...). Please note that running multiple instances of AsyncTask is a bad idea. Here is what I suggest:
if(isSyncSuccess){
SetConstant.IMAGE_EXIST=1;
pDialog=new ProgressDialog(GalleryScreen.this);
pDialog.setMessage("Downloading file. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setProgress(0);
pDialog.setMax(contentId.length);
pDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
pDialog.setCancelable(true);
new DownloadFile().execute();
}
private class DownloadFiles extends AsyncTask<String, Integer, String> {
#Override
protected String doInBackground(String... sUrl) {
Bitmap bm;
InputStream in;
if (contentId.length > 0) {
for (int i = 0; i < contentId.length; i++) {
if (helper.databaseChecking(useremail, contentId[i])) {
contentdownload = i;
SetConstant.CONTENT_ID = contentId[i];
String URL = SetConstant.URL_DOWNLOAD_CONTENT + contentId[i];
//YOUR INTRESTING LOOP HERE.
publishProgress(30);
//SOME INTRESTING NUMBER FOR PROGRESS UPDATE
}
}
try {
in = new java.net.URL(sUrl[0]).openStream();
bm = BitmapFactory.decodeStream(new PatchInputStream(in));
File storage = new File(Environment.getExternalStorageDirectory() + File.separator + "/Image/");
Log.i(TAG, "storage:" + storage);
Log.i(TAG, "storage:" + storage.getAbsolutePath());
if (!storage.exists()) {
storage.mkdirs();
}
String FileName = "/" + SetConstant.CONTENT_ID + ".jpg";
FileOutputStream fos = new FileOutputStream(storage + FileName);
bm.compress(Bitmap.CompressFormat.JPEG, 85, fos);
String filepath = storage + FileName;
File filecheck = new File(filepath);
long fileSize = filecheck.length();
fos.flush();
fos.close();
} catch (IOException e1) {
e1.printStackTrace();
}
return null;
}
#Override
protected void onPreExecute () {
super.onPreExecute();
pDialog.show();
}
#Override
protected void onProgressUpdate (Integer...progress){
super.onProgressUpdate(progress);
pDialog.setProgress(progress[0]);
}
protected void onPostExecute (String result){
super.onPostExecute(result);
pDialog.dismiss();
}
}
}
Of course this code don't run and you need to fix the scopes. But what I am trying to suggest is that your loop should be in doInBackGround(...), you should only have 1 instance of AsyncTask at given time for this case, and call the onProgressUpdate().
Primary issue :
SetConstant.CONTENT_ID = contentId[i];
String URL = SetConstant.URL_DOWNLOAD_CONTENT+contentId[i];
Here, you are facing trouble. As #Sofi Software LLC's answer, you are using a global variable, whose value is being changed by the main thread, in another thread.
Secondary Issue :
If you want a progress bar to update, you have to update its value;
it doesn't update itself.
You do need to download the image in AsyncTask (Downloading from URL). Effectively to achieve your functionality, you need to do
Create AsyncTask to download your image (implement download in
doInBackground()), also have a boolean (say isImageDownloaded) to
track if the image is successfully downloaded in postExecute().
Don't forget to also show your progress bar before initiating the
download
Execute your AsyncTask to initiate download
Create extension of android.os.CountDownTimer to countdown a minimum
time
On the method onFinish() check the boolean that you track, if it is
false then you cancel the AsyncTask and throw the toast/dialog that
you intended
Running multipule instance of AsyncTask is not a good idea, so do one after another. You can execute your AsyncTask's on an Executor using executeOnExecutor().To make sure that the threads are running in a serial fashion please use: SERIAL_EXECUTOR.
Following resources may help you #
If you need to download an image, show progress bar and load in a imageview
https://github.com/koush/UrlImageViewHelper
http://developer.aiwgame.com/imageview-show-image-from-url-on-android-4-0.html
http://blog.blundell-apps.com/imageview-with-loading-spinner/
If you need to download multiple files (here, for images) using AsyncTask
Problem with downloading multiple files using AsyncTask
How to get back the task completion status in AsyncTask
Implement Progress Bar for File Download in Android
EDIT:
From http://developer.aiwgame.com/imageview-show-image-from-url-on-android-4-0.html
new DownloadImageTask((ImageView) findViewById(R.id.imageView1))
.execute("http://java.sogeti.nl/JavaBlog/wp-content/uploads/2009/04/android_icon_256.png"); }
public void onClick(View v) {
startActivity(new Intent(this, IndexActivity.class));
finish();
}
private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> {
ImageView bmImage;
public DownloadImageTask(ImageView bmImage) {
this.bmImage = bmImage;
}
protected Bitmap doInBackground(String... urls) {
String urldisplay = urls[0];
Bitmap mIcon11 = null;
try {
InputStream in = new java.net.URL(urldisplay).openStream();
mIcon11 = BitmapFactory.decodeStream(in);
} catch (Exception e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return mIcon11;
}
protected void onPostExecute(Bitmap result) {
bmImage.setImageBitmap(result);
} }
From Image download in an Android ImageView and Progressbar implementation
// note that you could also use other timer related class in Android aside from this CountDownTimer, I prefer this class because I could do something on every interval basis
// tick every 10 secs (or what you think is necessary)
CountDownTimer timer = new CountDownTimer(30000, 10000) {
#Override
public void onFinish() {
// check the boolean, if it is false, throw toast/dialog
}
#Override
public void onTick(long millisUntilFinished) {
// you could alternatively update anything you want every tick of the interval that you specified
}
};
timer.start()
In the following line:
SetConstant.CONTENT_ID = contentId[i];
You're setting a global variable to a value, then you create a string url based on that same value and pass it to the AsyncTask. That executes, and then when it is done downloading, it create a file whose name is based on the global variable SetConstant.CONTENT_ID.
In other words, you are using a global variable, whose value is being changed by the main thread, in another thread. Don't do this, as you will get all kinds of weird problems due to the different threads updating at different times.. Pass in the value or the name of the output file to the AsyncTask. You can do that in a constructor for DownloadFile, and stash the value in a field.
If you want a progress bar to update, you have to update its value; it doesn't update itself. Call AsyncTask.publishProgress during the task (in doInBackground) and implement onProgressUpdate to update the progress dialog.
[EDIT: onProgressUpdate is indeed called in the UI thread.]
First create a separated class which allows you to reach to image address
like following:
public class ImageDownloader extends AsyncTask {
#Override
protected Bitmap doInBackground(String... urls) {
try {
URL url = new URL(urls[0]);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.connect();
InputStream inputStream = connection.getInputStream();
Bitmap myBitmap = BitmapFactory.decodeStream(inputStream);
return myBitmap;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
}
Then get access to that class (through a method called by a button) by creating an object and execute the Bitmap task like following :
public class MainActivity extends Activity {
ImageView downloadedImg;
public void downloadImage(View view) {
ImageDownloader task = new ImageDownloader();
Bitmap myImage;
try {
myImage = task.execute("YOUR IMAGE ADDRESS ........").get();
downloadedImg.setImageBitmap(myImage);
} catch (Exception e) {
e.printStackTrace();
}
}
Do NOT forget to:
1 - define the imageView in onCreat method ==> downloadedImg = (ImageView) findViewById(R.id.imageView);
2 - to link the method you've created by a button in user interface ==> (public void downloadImage(View view){})
3 - ask for permission in manifest file
why my imageview is not updating in the for loop,only the image from last url is showing in the imageview not all the images,what i am doing wrong?
public class LoadImageActivity extends Activity {
ImageView image_view;
Bitmap bitmap;
String[] imageLocation={
"http://wallbase1.org/thumbs/rozne/thumb-499842.jpg",
"http://ns3002439.ovh.net/thumbs/rozne/thumb-2493796.jpg",
"http://ns3002439.ovh.net/thumbs/rozne/thumb-2486664.jpg" };
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
image_view = (ImageView)findViewById(R.id.imageview);
for (int i = 0; i < 2; i++) {
bitmap = loadImage(imageLocation[i]);
image_view.setImageBitmap(bitmap);
Animation rotate = AnimationUtils.loadAnimation(LoadImageActivity.this, R.anim.rotate);
findViewById(R.id.imageview).startAnimation(rotate);
}
}
public Bitmap loadImage(String image_location){
URL imageURL = null;
try {
imageURL = new URL(image_location);
} catch (MalformedURLException e) {
e.printStackTrace();
}
try {
HttpURLConnection connection = HttpURLConnection)imageURL.openConnection();
connection.setDoInput(true);
connection.connect();
InputStream inputStream = connection.getInputStream();
bitmap = BitmapFactory.decodeStream(inputStream);//Convert to bitmap
} catch (IOException e) {
e.printStackTrace();
}
return bitmap;
}
}
Well, at first, how slow is you device that you would switch between images in two successing lines of code (effectively)?
Secondly, the system has to be layouted first which happens after onCreate() returns. What you did is:
-set reference to bitmap that will be shown when layouted
-changed that reference
-let the system do the layout (Question: Which reference will be read?)
It looks like you want to set the first bitmap, rotate it and then set the other bitmap.
What you need to do is:
-set bitmap
-start animation with an Animation.AnimationListener, which sets the second bitmap in onAnimationEnd().
#Thanks to Adam!
You can put an Animation.AnimationListener on your first animation, and you can load the next image and start the new transition in the onAnimationEnd(...) method of the listener.
Try setting the underlying object (Bitmap) and then updating the ImageView.
The method loadImage() is not in UI main Thread, use a Handler to update the ImageView with your new image.
The server is sending a list of urls of images when the application loads.
After parsing the url,The Application is Supposed to fetch that images from the server and display those images as MARQUEE on it's header as a BANNER.
On Clicking on that banner...a link is to be open(Say for example link of any WebSite).
Can Anybody tell me how to fetch this image from the url and Save it temporarily and Display them as Banner.
Regards.
I used this code for loding img form url
ImageView v_thumburl = (ImageView) rowView
.findViewById(R.id.v_thumb_url);
thumburl = temp.getString(temp.getColumnIndex("thumburl"));
Drawable drawable = LoadImageFromWebOperations(thumburl);
v_thumburl.setImageDrawable(drawable);
private Drawable LoadImageFromWebOperations(String url) {
try {
InputStream is = (InputStream) new URL(url).getContent();
Drawable d = Drawable.createFromStream(is, "src name");
return d;
} catch (Exception e) {
System.out.println("Exc=" + e);
return null;
}
}
try this i hope it may help u
Use AsyncTask for downloading images from server (Store them in external storage).
After complete the download display those images in Gallery view as a
Banner. (Put Gallery view in banner).
As Android Gallery doesn't support Marquee, use animation for Gallery
view (Like Marquee).
For Loading Image from The Server you can use LasyList which will fetch the image from server and store it into SD Card.
SlideShow will be better than Marquee, so if you want SlideShow see this
And If you want marquee then what you can so is have and HorizontalListView
Add a public Method in HorizontalListView Class as shown below
public void getScrollWidth() {
return mMaxX;
}
public void getCurrentScrollX() {
return mNextX;
}
and For Marquee have a Thread and a Handler in your class like this.
new Thread(new Runnable() {
#Override
public void run() {
try {
handler.post(new Runnable() {
#Override
public void run() {
if((horizontalListView.getCurrentScrollX() + 50) < horizontalListView.getScrollWidth())
{
horizontalListView.scrollTo(horizontalListView.getCurrentScrollX() + 50);
}
else
{
horizontalListView.scrollTo(0);
}
}
});
Thread.sleep(1000);
} catch (Exception e) {
}
}
}).start();
I am having a customized list view in my application, which is showing an image and text.
The Image I am getting from URL, using the code below:
private static Drawable ImageOperations(Context ctx, String url,
String saveFilename) {
try {
InputStream is = (InputStream) fetch(url);
Drawable d = Drawable.createFromStream(is, "src");
return d;
} catch (MalformedURLException e) {
e.printStackTrace();
return null;
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
public static Object fetch(String address) throws MalformedURLException,
IOException {
URL url = new URL(address);
Object content = url.getContent();
return content;
}
all is working perfect, except the list view scrolling, its very slow. If I disable the images, the scroll speed smooth-ens , but with the image enabled, it lags alot.
Is there any possible way I can reduce or remove this lagging?
Thanks
You need to do your fetching in the background.
One of the examples you can use :
http://android-developers.blogspot.com/2010/07/multithreading-for-performance.html
use this library for downloading images in background and caching..
it won't hurt the UI
https://github.com/koush/UrlImageViewHelper
Are you lazy loading your images? See this question for details.