OutofMemory ImageAdapter

Question

I'm try to get images(path) from the sqldatabase and put the images to a gridview. But I get often an OutOfMemoryError. This is my Code:

public void dos(File myDir)
{
    Cursor test;
    MyDB con = new MyDB(mContext);
    test = con.selectImages();

    List<String> array = new ArrayList<String>();
    while(test.moveToNext()){
        String uname = test.getString(2);
        array.add(uname);
    }


    List<File> list = new ArrayList<File>();

    for (int i = 0; i < array.size(); i++) {
        list.add(new File(myDir + "/" + array.get(i)));
    }

    System.out.println(list);

    for (File file : list) {
        mThumbs.add(Drawable.createFromPath(file.getPath()));
    }
}

public View getView(int position, View convertView, ViewGroup parent) {
    ImageView imageView;
    if (convertView == null) {  // if it's not recycled, initialize some attributes
        imageView = new ImageView(mContext);
        imageView.setLayoutParams(new GridView.LayoutParams(230, 310));
        imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
        imageView.setPadding(0, 0, 0, 0);
    } else {
        imageView = (ImageView) convertView;
    }

    imageView.setImageDrawable(mThumbs.toArray(new Drawable[list.size()])[position]);
    return imageView;
}

And this is the Error:
10-12 10:56:43.820 19786-19786/de.treevo.app E/AndroidRuntime﹕ FATAL EXCEPTION: main java.lang.OutOfMemoryError at android.graphics.BitmapFactory.nativeDecodeStream(Native Method) at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:530) at android.graphics.BitmapFactory.decodeFile(BitmapFactory.java:303) at android.graphics.BitmapFactory.decodeFile(BitmapFactory.java:329) at android.graphics.drawable.Drawable.createFromPath(Drawable.java:916) at de.treevo.app.ImageAdapter.dos(ImageAdapter.java:76) at de.treevo.app.main_list.onCreate(main_list.java:75) at android.app.Activity.performCreate(Activity.java:5133) at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2293) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2389) at android.app.ActivityThread.access$600(ActivityThread.java:153) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1269) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loop(Looper.java:137) at android.app.ActivityThread.main(ActivityThread.java:5289) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:525) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:739) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:555) at dalvik.system.NativeStart.main(Native Method)

My Code in main_list.java:

ImageAdapter image = new ImageAdapter(this);
image.dos(filedir)

GridView gridview = (GridView) findViewById(R.id.gridview);
gridview.setAdapter(image);

My Question: What can i do that it just work without any outofmemory Error. My Test Device is a Nexus 7 from Google.

Edit: Thanks for the reply meredrica. That explains a lot when every image is kept in memory. My new Question: What else could id do loag image names from the database and put them in a gridview?

Answer 1

You are leaking memory left and right. You are also holding every single image in memory, this will never work. I'm also pretty sure you will soon try to load an image that is too big which will again kill your ram. You need to load images in the right scale.

Android only allows some fixed set of RAM for each app to be used, then it will deny additional ram to the app which results in the OOMException.

Judging from your code, you should really read some android development guides, as you are programming like you are using desktop java. This will lead to a buggy app that keeps crashing and un-fixable code. I don't mean this as an offense, rather as a warning and advice. I've seen this many times before.