I am trying to populate a listview with custom made objects. I am using an
adapter to use the listview class. The following is the code I use to use the adapter.
adapter = new SearchListAdapter(this, values);
expListView = (ListView) findViewById(R.id.SearchList);
setListAdapter(adapter);
In the SearchListAdapter class I have the following code:
public class SearchListAdapter extends ArrayAdapter<String>
{
private Context context;
private ArrayList<String> values;
public SearchListAdapter(Context context, ArrayList<String> UsernameValues) {
super(context, R.layout.search_contact, UsernameValues);
this.context = context;
this.values = UsernameValues;
}
#Override
public View getView(int position, View convertView, ViewGroup parent)
{
LayoutInflater inflater = (LayoutInflater) this.context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View rowView = inflater.inflate(R.layout.search_contact, parent, false);
TextView textView = (TextView) rowView.findViewById(R.id.firstLine);
for(String Index : values)
{
textView.setText(Index);
}
return rowView;
}
}
I can see that the setListAdapter is working (I assume), as it is passing the information into the SearchListAdapter, but when the getView tries to populate the list, it just enters the last String value from the ArrayList in every single element in the list. What am I missing to make it so every single element corresponds to a value in the ArrayList? Any help is appreciated, thanks.
Your code
for(String Index : values)
{
textView.setText(Index);
}
is actually iterating over your complete data List and setting each value at every iteration. So, after the last iteration, every textView is left with the last value in your adapter's backing List.
What you need is to only set that value that corresponds to the current row position of your ListView in your UsernameValues list.
textView.setText(values.get(position));
Related
I am running into some difficulty with populating values to a listview, which currently displays no rows.
Firstly I am retrieving values from my database table and storing them in Arrays within onPostExecute.
LikedListAdapter listAdapter = new LikedListAdapter(context, R.layout.liked_list_main, restID, restName, restAddr1, restAddr2, restImgPath);
lvPlaces.setAdapter(listAdapter);
These values are then successfully passed into my ListAdapter.
public LikedListAdapter(Context context, int resource, String[] restID, String[] restName, String[] restAddr1, String[] restAddr2, String[] restImgPath) {
super(context, resource);
this.context = context;
this.resource = resource;
this.restID = restID;
this.restName = restName;
this.restAddr1 = restAddr1;
this.restAddr2 = restAddr2;
this.restImgPath = restImgPath;
}
#Override
public View getView(int position, View convertView, ViewGroup parent)
{
LinearLayout likedItemsView;
if(convertView==null) {
likedItemsView = new LinearLayout(getContext());
String inflater = Context.LAYOUT_INFLATER_SERVICE;
LayoutInflater vi;
vi = (LayoutInflater)getContext().getSystemService(inflater);
vi.inflate(resource, likedItemsView, true);
}
else {
likedItemsView = (LinearLayout) convertView;
}
ImageView restaurantImg = (ImageView)likedItemsView.findViewById(R.id.listItemThumbImg);
TextView restaurantName =(TextView)likedItemsView.findViewById(R.id.listItemTitle);
TextView restaurantDesc = (TextView)likedItemsView.findViewById(R.id.listItemSubText);
restaurantName.setText(restName[position]);
restaurantDesc.setText(restAddr1[position] + ", " + restAddr2[position]);
Picasso
.with(getContext())
.load(restImgPath[position])
.into(restaurantImg);
return likedItemsView;
}
However, when i run the app the Listview is empty. When debugging i notice that the values are successfully passed to my listAdapter (on debugging it displays the values retrieved being displayed in the constructor) however it never hits the method getView, where values are set to each listview widget.
Is there something i am misunderstanding, or do i need to call the getView method at some point? Thanks in advance.
Did you override
getCount()
method? If not then return the size of your rows. Ex-
#Override
public int getCount() {
return restName.length;
}
Hope your problem will be solved. If already populated list then use
adapter.notifyDataSetChanged()
method.
LikedListAdapter listAdapter = new LikedListAdapter(context, R.layout.liked_list_main, restID, restName, restAddr1, restAddr2, restImgPath);
lvPlaces.setAdapter(listAdapter);
listAdapater.notifyDataSetChanged(); // <-- add this
I have made a ListView which is populated with elements of an ArrayList. I do not have an XML file with this ListView, it is only in Java. Given this, how would I change the background color of the ListView as well as change the color of the text of the ListView?
This is the code for the ListView:
setListAdapter(new ArrayAdapter<String>(CollegeList.this, android.R.layout.simple_list_item_1, nameList));
In case you want to customize each line of the listview you have to use a custom adapter with custom listview item. Then you can use the "getView" Method to catch each item and position to change colors.
Here is a sample:
public class ListViewAdapter extends ArrayAdapter<Item> {
private Context context;
private int itemResourceId;
private ArrayList<Item> items;
public ListViewAdapter(Context context, int layoutId, ArrayList<Item> items) {
super(context, layoutId, items);
this.context = context;
this.itemResourceId = layoutId;
this.items = items;
}
#Override
public View getView(int position, View view, ViewGroup parent) {
ViewHolder holder = null;
if (view == null) {
holder = new ViewHolder();
LayoutInflater inflater = (LayoutInflater)getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
view = inflater.inflate(itemResourceId, null);
holder.listItem = (TextView) view.findViewById(R.id.item);
view.setTag(holder);
}
else
holder = (ViewHolder) view.getTag();
if (position % 2 == 0)
view.setBackgroundColor(context.getResources().getColor(R.color.listItemEven));
else
view.setBackgroundColor(context.getResources().getColor(R.color.listItemOdd));
Item item = items.get(position);
holder.listItem.setText((position+1) + ". " + item.sTitle);
return view;
}
static class ViewHolder {
TextView listItem;
}
}
android.R.layout.simple_list_item_1
You have to add an extra parameter to your ArrayAdapter, this will be a CUSTOM XML OF YOUR OWN and the next one will be a textview that is inside that custom layout, that way the array adapter will know which layout to fill and which textview needs to show the data you want to show.
from that xml you can modify background and color. will look something like this:
setListAdapter(new ArrayAdapter<String>(CollegeList.this, R.layout.your_custom_layout, R.id.the-text-view-in-that-layout, nameList));
You can get the xml for simple_list_item_1 here. You can copy it to your project and modify it, just change the code for your listview to setListAdapter(new ArrayAdapter<String>(CollegeList.this, R.layout.simple_list_item_1, nameList)); You can also create one yourself, since simple_list_item_1 is nothing but a textview. Just make sure that the id is android:id="#android:id/text1" otherwise it won't work with the default adapter.
I was just asking myself if there was a way of making a ListView without any texts. I've only found ListViews with images + texts, and that exactly what i dont want. I just want to add a lot of images like in a list and don't want to make it with ImageView because that makes my app crash. Also, i dont want my app to lag. Thanks!
this is what i got in my activity_main.xml
<ListView
android:id="#+id/listview"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
and i found this from another post that actually helped me, but it doesnt display all images
public class MainActivity extends Activity {
// Array of integers points to images stored in /res/drawable-hdpi/
int[] vehs = new int[]{
R.drawable.veh1,
R.drawable.veh2,
R.drawable.veh3,
R.drawable.veh4,
R.drawable.veh5,
R.drawable.veh6,
R.drawable.veh7,
R.drawable.veh8,
R.drawable.veh9,
R.drawable.veh10,
R.drawable.veh11,
R.drawable.veh12,
R.drawable.veh13,
R.drawable.veh14,
R.drawable.veh15,
R.drawable.veh16,
R.drawable.veh17,
R.drawable.veh18,
R.drawable.veh19,
R.drawable.veh20,
R.drawable.veh21,
R.drawable.veh22,
R.drawable.veh23,
R.drawable.veh24,
R.drawable.veh25,
R.drawable.veh26,
R.drawable.veh27,
R.drawable.veh28,
R.drawable.veh29,
R.drawable.veh30,
R.drawable.veh31,
R.drawable.veh32,
R.drawable.veh33,
R.drawable.veh34,
R.drawable.veh35,
R.drawable.veh36,
};
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Each row in the list stores country name, currency and flag
List<HashMap<String,String>> aList = new ArrayList<HashMap<String,String>>();
for(int i=0;i<10;i++){
HashMap<String, String> hm = new HashMap<String,String>();
hm.put("vehs", Integer.toString(vehs[i]) );
aList.add(hm);
}
// Keys used in Hashmap
String[] from = { "vehs","txt","cur" };
// Ids of views in listview_layout
int[] to = { R.id.vehs,R.id.txt,R.id.cur};
// Instantiating an adapter to store each items
// R.layout.listview_layout defines the layout of each item
SimpleAdapter adapter = new SimpleAdapter(getBaseContext(), aList, R.layout.listview_layout, from, to);
// Getting a reference to listview of main.xml layout file
ListView listView = ( ListView ) findViewById(R.id.listview);
// Setting the adapter to the listView
listView.setAdapter(adapter);
}
}
Didn't edit all the code, so you might find some things confusing xD
The way ListView displays data is by using an adapter. The adapter takes your data, inserts it into a custom view, and then adds it to the list.
To build a fast images ListView, the first thing you'd want to do is to add Picasso to your project. This library will automatically download and cache your images, handle ImageView recycling, and more.
The next thing you'd want to do is to write your item view. If you want an images-only list, the view could be as simple as:
<!-- res/layout/list_item.xml -->
<?xml version="1.0" encoding="utf-8"?>
<ImageView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="?android:attr/listPreferredItemHeight" />
Next, you want to create your adapter. It accepts a List<String> of image URLs as an input, builds the items and inserts them to the ListView.
public class ImageListAdapter extends ArrayAdapter<String> {
List<String> items;
public ImageListAdapter(Context context, int resource, List<String> items) {
super(context, resource, items);
this.items = items;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
if (convertView == null) {
LayoutInflater inflater = LayoutInflater.from(getContext());
convertView = inflater.inflate(R.layout.list_item, null);
}
Picasso.with(getContext())
.load(items.get(position))
.into((ImageView) convertView);
return convertView;
}
}
Read the Picasso library documentation if you want to add more options such as image placeholders, transformations, and more.
Finally, to use the adapter on your ListView, add this to your activity's onCreate method:
List<String> images = new ArrayList<String>();
images.add("http://hometowncolumbia.files.wordpress.com/2007/12/lol-cats-dont-look-behind-cat.jpg");
images.add("http://i232.photobucket.com/albums/ee245/topswing/cat-lol.jpg");
listView = (ListView)findViewById(R.id.myListView);
listView.setAdapter(new ImageListAdapter(this, R.layout.list_item, images))
In a real application though, you'd probably want to load the image list from your server. You'd need to use an AsyncTask for that.
Don't make things difficult, the solution is simple in the classic 3 steps
Step 1:
Make a RelativeLayout in XML. Move the image to desired position (always to center, but you can choose if left or right) and change layout_height to wrap_content
Step 2:
Create a custom adapter for ListView, if you do this, you'll be able to all any layout as an item
public class ImagesAdapter extends ArrayAdapter<String> {
private Activity mContext;
private ArrayList<Bitmap> mImages;
public ImagesAdapter(Activity context, ArrayList<String> listOfValues, ArrayList<Bitmap> images) {
//The listOfValues is used when you make item click to get value
//Each image must to have a text value
super(context, R.layout.yourlayout, listOfValues);
mContext = context;
mImages = images;
}
#Override
public void getView(int position, View convertView, ViewGroup parent) {
LayoutInflater inflater = mContext.getLayoutInflater();
View returnView = inflater.inflate(R.layout.yourlayout, null);
ImageView imageView = (ImageView) returnView.findViewById(R.id.yourimageid);
imageView.setImageBitmap(mImages.get(position));
return returnView;
}
}
Step 3:
Implement in your code
ImagesAdapter adapter = new ImagesAdapter(this, myList, myImages);
mylistView.setAdapter(adapter);
myListView.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
//volov = Values Of ListOfValues
String volov = (String) myListView.getItemPosition(position);
Log.i(TAG, "listOfValues is useful " + volov);
}
});
This one has me quite stumped. I'm sure it is just something simple I am missing, but I cant seem to find out what...
When I run the program, it opens up the dialog box and displays the AutoCompleteTextView I have initialized. When I try to type something into it, nothing drops down or is displayed other than the text I type in. I have created a similar system in another part of my program with the same mechanics, but using a regular ArrayAdapter and it works fine so the interface is not the problem.
Here is where I initialize my custom ArrayList. I have been trying to use just strings to make it simpler.
final Dialog weaponDialog = new Dialog(BattleScreen.this);
weaponDialog.setContentView(R.layout.weapon_selection_dialog);
weaponDialog.setTitle("Add a Weapon");
weaponDialog.setCancelable(true);
String[] weaponStringArrayList = ConstantEquipmentHelper.getCondensedWeaponString();
WeaponArrayAdapter weaponAdapter = new WeaponArrayAdapter(this, R.layout.weapon_list_item, weaponStringArrayList);
weaponDialogAcTextView = (AutoCompleteTextView) weaponDialog.findViewById(R.id.weaponSelectionAutoCompleteTxt);
weaponDialogAddButton = (Button) weaponDialog.findViewById(R.id.weaponSelectionAddButton);
weaponDialogWeaponInfo = (TextView) weaponDialog.findViewById(R.id.weaponSelectionInformationTxt);
...
...
...
Here is my custom ArrayAdapter Class
public class WeaponArrayAdapter extends ArrayAdapter<String> {
private Context context;
String[] objects;
public WeaponArrayAdapter(Context context, int textViewResourceId, String[] objects) {
super(context, textViewResourceId);
this.objects = objects;
this.context = context;
}
private class WeaponItemHolder {
TextView weaponName;
TextView weaponCat;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
//return super.getView(position, convertView, parent);
final WeaponItemHolder holder;
if (convertView == null) {
//Sets up a new holder to temporaraly hold the listeners that will be assigned to the binded variables
holder = new WeaponItemHolder();
inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(R.layout.weapon_list_item, null);
//Find the IDs! Find them!!!!
holder.weaponName = (TextView) convertView.findViewById(R.id.weaponListItemName);
holder.weaponCat = (TextView) convertView.findViewById(R.id.weaponListItemCategory);
//"Sets the tag associated with this view. A tag can be used
//to mark a view in its hierarchy and does not have to be unique within the hierarchy."
convertView.setTag(holder);
} else {
holder = (WeaponItemHolder) convertView.getTag();
}
String spellName = objects[position];
String[] weaponInfo = spellName.split("\\:");
weaponInfo[1] = weaponInfo[1].trim();
holder.weaponName.setText(weaponInfo[0]);
holder.weaponCat.setText(weaponInfo[1]);
return convertView;
}
}
Additional Info: I have tried debugging it and it never reaches getView. This makes sense of course, as its not displaying anything.
Thanks,
-Andrew
EDIT: I have found out how to implement the above problem:
I used a SimpleAdapter with a custom layout.
However, now I can not select any of the items... onItemClick is not even called when I try to click it. It probably has to do with using the SimpleAdapter??
LINK: http://lemonbloggywog.wordpress.com/2011/02/15/customer-autocomplete-contacts-android/
ArrayList<Map<String, String>> weaponStringArrayList = ConstantEquipmentHelper.getCondensedWeaponString();
//The adapter that recieves the layout type from android and the array creatd by the above function.
SimpleAdapter simpleAdapter = new SimpleAdapter(this, weaponStringArrayList, R.layout.weapon_list_item ,new String[] {"name", "category"}, new int[] { R.id.weaponListItemName, R.id.weaponListItemCategory});
//Find the view blah blah blah...
weaponDialogAcTextView = (AutoCompleteTextView) weaponDialog.findViewById(R.id.weaponSelectionAutoCompleteTxt);
weaponDialogAddButton = (Button) weaponDialog.findViewById(R.id.weaponSelectionAddButton);
weaponDialogWeaponInfo = (TextView) weaponDialog.findViewById(R.id.weaponSelectionInformationTxt);
//Set that adapter!
weaponDialogAcTextView.setAdapter(simpleAdapter);
You have to implement getCount() and set the count of your data, i.e. objects.length.
You also have to set the adapter to the view using the method setAdapter().
Hope this helps!
The title pretty much says it all. I have a listview being populated by a simple adapter and an xml layout that changes based on how many rows are present in the listview item. When I add data to one of the items in the activity, calling the notifyondatasetchanged does not update the list, but if I back out of the activity and go back in everything looks the way it should. What do I need to do so when I refresh the adapter the getview gets updated as well?
public AlarmListAdapter(Context context, ArrayList<HashMap<String, String>> list, int textViewResourceId, String[] fields, int[] textViewId) {
super(context, list, textViewResourceId, fields, textViewId);
this.list = list;
this.context = context;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
View v = convertView;
if (v == null) {
LayoutInflater vi = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = vi.inflate(R.layout.alarm_list_item, null);
}
if(list.get(position).get("alert") == null){
v.findViewById(R.id.ListViewItemSub).setVisibility(View.GONE);
}
return super.getView(position, convertView, parent);
}
public void forceReload(){
notifyDataSetChanged();
}
The notifyondatasetchanged is being called from a popup within my activity. The code for that button is listed below:
addCustomAlertButton = (Button)pView.findViewById(R.id.AddCustomAlertButton);
addCustomAlertButton.setOnClickListener(new OnClickListener(){
public void onClick(View v){
arrayList.get((int) customAlertId).setAlertDialog(customAlertInput.getText().toString());
Toast.makeText(EditAlarmsActivity.this, "Custom Alert Added", Toast.LENGTH_SHORT).show();
updateListArray();
pw.dismiss();
}
You could try setListAdapter(yourAdapter);
or listview.requestLayout();
If those didn't work then you could also try refreshing the listview through scrolling, since the getView() function is called once the listview is scrolled.