Hi so i've been toying with this and can't seem to get the grip of
it... My problem is that ConvertView always is null, and therefore a
lot of imageoperations is being done everytime the gallery is
scrolling or touched -> ergo i get an OOM exception...
My getView() is looking like this now, am I doing something wrong
(obviously i must be...)
public View getView(int position, View convertView, ViewGroup parent)
{
if(convertView == null)
{
Controller co = Controller.GetInstance();
ImageView imageView = new ImageView(context);
if(co.server.currRecord.image.get(position).containsKey("data"))
{
// we have a content URI and need to get it converted into a
down scaled BitmapDrawable
String uri =
co.server.currRecord.image.get(position).get("data").toString();
co.server.currRecord.image.get(position).put("BM",
FileConvert.BitmapFromContenturi(uri));
imageView.setImageDrawable((BitmapDrawable)co.server.currRecord.image.get(position).get("BM"));
}
else
{
//we have a web url and need to get it converted into a down
scaled BitmapDrawable
String url =
(String)co.server.currRecord.image.get(position).get("url");
co.server.currRecord.image.get(position).put("BM",
FileConvert.BitmapFromURL(url));
imageView.setImageDrawable((BitmapDrawable)co.server.currRecord.image.get(position).get("BM"));
}
imageView.setScaleType(ImageView.ScaleType.FIT_XY);
imageView.setLayoutParams(new Gallery.LayoutParams(150, 120));
imageView.setBackgroundResource(itemBackground);
return imageView;
}
else{
return convertView;
}
}
- Lars
On 26 Apr., 09:55, Romain Guy <[email protected]> wrote:
> Hi,
>
> As written, your getView() method *never* reuses the convertView
> parameter. This means you are creating new Views and new Bitmaps every
> time the method is called, which happen very often while
> scrolling/flinging a grid.
>
> You first need to start using the convertView when possible (if
> convertView != null, cast it to an ImageView and set your drawable on
> it.) Note that setting the scale type, layout params and background
> resource should be done only when convertView == null. This will save
> you a lot of time.
>
> Finally, you should create a cache for your bitmaps to avoid reloading
> them all the time.
>
> I encourage you to read the source code of the following application
> to see how to implement an efficient list of
> images:http://code.google.com/p/shelves/
>
> Also refer to my Google I/O 2009 talk about UI
> optimization:http://code.google.com/events/io/2009/sessions/TurboChargeUiAndroidFa...
> In this talk I describe how to implement getView() efficiently and
> talk about image caches briefly at the end.
>
>
>
> On Mon, Apr 26, 2010 at 12:50 AM,Lars<[email protected]> wrote:
> > Hi
>
> > I have a gallery in wich I show a row of images, the images can both
> > be from the Camera gallery or from the internet as a web url. My
> > getView() method makes an exception when I put to many images from the
> > gallery inside it. Should i down sample the images before attaching
> > them to the view? and how is that done ? heres my getView method:
>
> > public View getView(int position, View convertView, ViewGroup parent)
> > {
>
> > Controller co = Controller.GetInstance();
>
> > ImageView imageView = new ImageView(context);
>
> > if(co.server.currRecord.image.get(position).containsKey("data"))
> > {
> > // we have a content URI and assign it to the gallery
>
> > imageView.setImageURI((Uri)co.server.currRecord.image.get(position).get("data"));
> > }
> > else
> > {
> > //we have a web url and need our ImageOperation method to
> > fetch and decode the drawable.
>
> > imageView.setImageDrawable(FileConvert.ImageOperations(context,
> > Controller.GetInstance().server.currRecord.image.get(position).get("url").toString()));
> > }
>
> > imageView.setScaleType(ImageView.ScaleType.FIT_XY);
> > imageView.setLayoutParams(new Gallery.LayoutParams(150, 120));
> > imageView.setBackgroundResource(itemBackground);
>
> > return imageView;
> > }
>
> > -Lars
>
> > --
> > You received this message because you are subscribed to the Google
> > Groups "Android Developers" group.
> > To post to this group, send email to [email protected]
> > To unsubscribe from this group, send email to
> > [email protected]
> > For more options, visit this group at
> >http://groups.google.com/group/android-developers?hl=en
>
> --
> Romain Guy
> Android framework engineer
> [email protected]
>
> Note: please don't send private questions to me, as I don't have time
> to provide private support. All such questions should be posted on
> public forums, where I and others can see and answer them
>
> --
> You received this message because you are subscribed to the Google
> Groups "Android Developers" group.
> To post to this group, send email to [email protected]
> To unsubscribe from this group, send email to
> [email protected]
> For more options, visit this group
> athttp://groups.google.com/group/android-developers?hl=en
--
You received this message because you are subscribed to the Google
Groups "Android Developers" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to
[email protected]
For more options, visit this group at
http://groups.google.com/group/android-developers?hl=en
