That's right, with the code above, it still GCs about 13000 every 2
seconds (as long as I'm scrolling the list quickly back and forth). If
I comment out the formatter line (price = mFormatter.format("%.2f",
args).toString();) it doesn't do the GCs anymore, but I of course lose
my formatting.On Apr 14, 10:28 am, Marco Nelissen <[email protected]> wrote: > When you say that it hasn't improved yourgarbagecollection problem, > do you mean that it still GCs 13000 objects every 2 seconds? > > On Mon, Apr 13, 2009 at 10:42 PM, DavidG <[email protected]> wrote: > > > Thanks for the feedback.. Now I'm trying to use StringBuilder and > > Formatter, but I just can't get it to stop doing thegarbage > > collection. I'm not sure how to go about reusing the Formatter. At > > first, I just tried creating a public static Formatter member variable > > and using it directly: > > > public Formatter mFormatter = new Formatter(); > > (then later within setViewValue()... ) > > mFormatter.format("%.2f",pricef).toString(); > > > Unfortunately the formatter seemed to keep "building" onto itself, > > making each item in the list return a longer and longer string as I > > scrolled. > > > Then I looked into the Android source code and found an example that I > > tried to mimick. While it gives me the output I expect, it hasn't > > improved mygarbagecollection problem. I'm just going to post the > > majority of my ViewBinder class, can someone point out where I'm going > > wrong? > > > <START CODE> > > import java.util.Formatter; > > import android.database.Cursor; > > import android.graphics.Color; > > import android.graphics.Paint; > > import android.view.View; > > import android.widget.ImageView; > > import android.widget.SimpleCursorAdapter; > > import android.widget.TextView; > > > public class ItemBinder implements SimpleCursorAdapter.ViewBinder { > > > public static final StringBuilder mBuilder = new StringBuilder(); > > public static final Formatter mFormatter = new Formatter(mBuilder); > > public static final Object[] mArgs = new Object[1]; > > > public boolean setViewValue(View view, Cursor cursor, int > > columnIndex) { > > switch(view.getId()) { > > case R.id.price: > > // Format the price nicely > > String price = cursor.getString(columnIndex); > > final float pricef = Float.parseFloat(price); > > Object[] args = mArgs; > > args[0] = pricef; > > mBuilder.setLength(0); > > price = mFormatter.format("%.2f", args).toString(); > > ((TextView)view).setText(price); > > return true; > > } > > return false; > > } > > } > > <END CODE> > > > On Apr 13, 10:40 pm, Marco Nelissen <[email protected]> wrote: > >> Don't use String.format(). It creates all kinds of temporary objects > >> every time you call it. > >> Instead, create a single StringBuilder and Formatter, and then reuse > >> those every time you need to format a string. > > >> On Mon, Apr 13, 2009 at 7:37 PM, DavidG <[email protected]> wrote: > > >> > In my ListView, there'sonelineof code in my ViewBinder that causes > >> > lots ofgarbagecollection as I scroll through the list, about every > >> > two seconds... > > >> > D/dalvikvm(16312): GC freed 13171 objects / 659576 bytes in 162ms > >> > D/dalvikvm(16312): GC freed 13122 objects / 654128 bytes in 129ms > >> > D/dalvikvm(16312): GC freed 13134 objects / 655416 bytes in 142ms > >> > D/dalvikvm(16312): GC freed 13129 objects / 654840 bytes in 129ms > >> > D/dalvikvm(16312): GC freed 13149 objects / 655000 bytes in 110ms > >> > D/dalvikvm(16312): GC freed 13150 objects / 655720 bytes in 127ms > >> > D/dalvikvm(16312): GC freed 13075 objects / 652256 bytes in 111ms > >> > D/dalvikvm(16312): GC freed 13232 objects / 659040 bytes in 136ms > >> > D/dalvikvm(16312): GC freed 13106 objects / 653920 bytes in 110ms > >> > D/dalvikvm(16312): GC freed 13155 objects / 655152 bytes in 110ms > > >> > The offending code is here, which formats a price for each item in the > >> > list: > > >> > String price = cursor.getString(columnIndex); > >> > final float pricef = Float.parseFloat(price); > >> > price = new StringBuffer("$").append(String.format("%. > >> > 2f",pricef)).toString(); > >> > ((TextView)view).setText(price); > > >> > If I comment out thelinewith String.format, thegarbagecollection > >> > goes away. So what's the "right" way to do this to avoid allocations? > >> > That database field holds an unformatted text string which I'm trying > >> > to format into proper currency format (example: format "1.5" to > >> > "$1.50") > > >> > Any pointers on how to improve this? > > --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
