How to refresh a GridView?

Question

I have a GridView which is pretty similar to the Google tutorial, except that I want to add the ImageViews on runtime (via a subactivity). The results are okay, but the layo

Answer 1

You must, first tell the adapter to notify that the data has changed and set the adapter again to the grid

adapter.notifyDataChanged();
grid.setAdapter(adapter);

Answer 2

This may be helpful. I refresh a gridview of book image thumbnails after a delete is executed on an item. Using adapter.notifyDataChanged(); as mentioned above didn't work for me as it's called in my adapter.

//this is a call that retrieves cached data.
//your constructor can be designed and used without it.
final Object data = getLastNonConfigurationInstance();

I essentially just reload the adapter and bind it to the same view.

//reload the adapter
adapter = new BooksAdapter(MyBooks.this, MyBooks.this, data, show_collection );
grid.invalidateViews();
grid.setAdapter(adapter);

Answer 3

@flyerz @snagnever

Together you guys have got it. It should be:

adapter.notifyDataChanged();
grid.invalidateViews();

This will flag the adapter that its data has changed, which will then be propagated to the grid whenever after the invalidateViews() method is called.

Glad I found this question because I could not figure out how to add items to the grid after its been rendered.

Answer 4

You are placing the GridView inside com.unimelb.pt3.ui.TransparentPanel which is 10px tall.

• You shouldn't use px, you should use dp.
• Change com.unimelb.pt3.ui.TransparentPanel's android:layout_height="10px" to android:layout_height="fill_parent"

Answer 5

the GridView has an invalidateViews() method.

when you call this method: "all the views to be rebuilt and redrawn." http://developer.android.com/reference/android/widget/GridView.html

i think this is what you need:)

Answer 6

In your adapter :

class MAdapter extends BaseAdapter{
   List<Objects> mObjects;
...

 public void clearAdapter(){
        mObjects.clear();
    }

 public void addNewValues(List<Objects> mObjects){
        this.mObjects = mObjects;
    }

...

}


adapter.clearAdapter(); // clear old values
adapter.addNewValues(MObjects);
adapter.notifyDataChanged();