Thank you for your response, and I can understand your confusion. Yes, when I run this activity, my screen displays the title text, two items in my ListView (0 = "Big Sound", 1 = "Little Sound"), and the footer text. I can select either or both items, and when I press Back, I can step through my onPause (you are correct here, pardon my bad form) and watch the selection indices get saved to "selectedSounds" preference.
>From what I've observed through careful debugging, I'm not having any issues saving the selections. Nor am I having issues retrieving these selections from preferences, or setting the ArrayAdapter to my ListView. The breakdown occurs when I try to set these items as checked in the ListView when the activity starts back up. > Don't use 'getChildCount' and 'getChildAt' method to check your > preference-settings. What is the proper method? I think this is the crux of my question. Again, I appreciate the help. I think some further guidance is needed. On Oct 7, 3:30 pm, Streets Of Boston <[email protected]> wrote: > Your activity (and your list-view) is not yet visible in the onStart. > > Don't use 'getChildCount' and 'getChildAt' method to check your > preference-settings. > > BTW: If your activity is not yet visible, how can a user make a > selection? > Shouldn't you query in the onPause, for example. > And also, the positions returned by the method getCheckedItemPositions > () are the positions in your adapter (ArrayAdapter in your case). Your > list-*view* positions (used in getChildAt) are not the same. You list- > view will never have more children than the ones you can see. And the > child-at postion 0 is the one on the top of the list-view. > > On Oct 7, 2:37 pm, KhanAzul <[email protected]> wrote: > > > I want to display a ListView with checkboxes, and I want some of the > > checkboxes pre-selected. The ListView has setAdapter called during > > onCreate, and the list information appears when the screen is drawn. > > However, when I attempt to set certain list items as checked, my > > ListView reports getChildCount() = 0. > > > My SharedPreferences contains a list of sounds that have been > > previously selected, as a comma delimited string of list indices. > > Because the list appears to have no children in onStart, my attempts > > to set items as checked fails. > > > On the good side, once the list is rendered, I can select entries and > > hit Back, and my selection is stored to SharedPreferences correctly. > > > How can I load my previous selection into the list? Should I be using > > something else here? > > > In the spirit of open source, here's my code, free to you :) > > > ==================================================== > > SoundLibrary.Java > > ==================================================== > > > import java.util.Hashtable; > > > import android.app.Activity; > > import android.content.Context; > > import android.content.SharedPreferences; > > import android.content.res.Resources; > > import android.media.MediaPlayer; > > import android.os.Bundle; > > import android.util.SparseBooleanArray; > > import android.view.View; > > import android.view.View.OnLongClickListener; > > import android.widget.ArrayAdapter; > > import android.widget.ListView; > > > public class SoundLibrary extends Activity{ > > ListView lstSounds; > > Hashtable<String, Integer> soundTable; > > CharSequence[] soundNames; > > CharSequence[] soundLocations; > > OnLongClickListener previewListener; > > static Context myContext; > > static MediaPlayer player; > > SharedPreferences prefs; > > > @Override > > public void onCreate(Bundle savedInstanceState) { > > super.onCreate(savedInstanceState); > > setContentView(R.layout.soundlibrary); > > myContext = this.getApplicationContext(); > > prefs = getSharedPreferences("myAppData", 0); > > > soundTable = new Hashtable<String, Integer>(); > > LoadSoundTable(); > > lstSounds = (ListView)findViewById(R.id.lstSounds); > > PopulateSoundList(); > > lstSounds.setOnLongClickListener(new PreviewListener()); > > } > > > @Override > > public void onStart() { > > super.onStart(); > > String[] selectedSoundsArray = > > prefs.getString("selectedSounds", "").split(","); > > for (int selI = 0; selI < selectedSoundsArray.length; > > selI++) { > > if (lstSounds.getChildCount() <= selI) { > > break; > > } > > try { > > > > lstSounds.getChildAt(Integer.parseInt(selectedSoundsArray > > [selI])).setSelected(true); > > } catch (NumberFormatException e) { } > > } > > } > > > @Override > > public void onPause() { > > super.onPause(); > > StringBuffer sb = new StringBuffer(); > > SparseBooleanArray sbaSelectedSounds = > > lstSounds.getCheckedItemPositions(); > > for (int sbaKey = 0; sbaKey < sbaSelectedSounds.size(); > > sbaKey++) > > { > > if (sbaSelectedSounds.get(sbaKey, false)) > > { > > sb.append(String.valueOf(sbaKey)); > > sb.append(','); > > } > > } > > prefs.edit().putString("selectedSounds", > > sb.toString()).commit(); > > } > > > private void LoadSoundTable() > > { > > Resources res = getResources(); > > CharSequence[] soundNames = > > res.getTextArray(R.array.sound_name); > > CharSequence[] soundLocations = > > res.getTextArray(R.array.sound_location); > > > for (int i = 0; i < soundNames.length; i++) { > > soundTable.put(soundNames[i].toString(), > > > > res.getIdentifier(soundLocations[i].toString(), "raw", > > this.getPackageName())); > > } > > } > > > private void PopulateSoundList() > > { > > ArrayAdapter<String> aa = new ArrayAdapter<String>(this, > > android.R.layout.simple_list_item_multiple_choice, > > soundTable.keySet().toArray(new > > String[soundTable.keySet > > ().size()])); > > lstSounds.setAdapter(aa); > > } > > > private class PreviewListener extends Activity implements > > OnLongClickListener { > > public boolean onLongClick(View v) { > > String previewSoundName = > > lstSounds.getSelectedItem().toString(); > > player = MediaPlayer.create(myContext, > > > > soundTable.get(previewSoundName).intValue()); > > player.start(); > > return true; > > } > > } > > > } > > > ==================================================== > > soundlibrary.xml - in res/layout > > ==================================================== > > > <?xml version="1.0" encoding="utf-8"?> > > <LinearLayout > > xmlns:android="http://schemas.android.com/apk/res/android"; > > android:layout_width="fill_parent" > > android:layout_height="wrap_content" > > android:gravity="center" > > android:orientation="vertical"> > > > <TextView > > android:layout_width="wrap_content" > > android:layout_height="wrap_content" > > android:id="@+id/txtTitle" > > android:text="@string/sound_library_title"></TextView> > > > <ListView > > android:id="@+id/lstSounds" > > android:layout_width="fill_parent" > > android:layout_height="fill_parent" > > android:choiceMode="multipleChoice" > > android:clickable="true" > > android:focusable="true" > > android:longClickable="true"></ListView> > > > <TextView > > android:layout_width="wrap_content" > > android:layout_height="wrap_content" > > android:id="@+id/txtPreview" > > android:text="@string/sound_library_preview"></TextView> > > > </LinearLayout> > > > ==================================================== > > sounds.xml - in res/values > > ==================================================== > > <?xml version="1.0" encoding="utf-8"?> > > <resources> > > <string-array name="sound_name"> > > <item>Big Sound</item> > > <item>Little Sound</item> > > </string-array> > > <string-array name="sound_location"> > > <item>test_big_sound</item> > > <item>test_little_sound</item> > > </string-array> > > </resources> --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Android Developers" group. 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