Develop Reference

I don't understand Android AutoCompleteTextView Constructor of ArrayAdapter

I want to use AutoCompleteTextView in android and read the official developer.android documentation about it.
There is a code snippet which looks like:
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_dropdown_item_1line, COUNTRIES);
AutoCompleteTextView textView = (AutoCompleteTextView)
findViewById(R.id.countries_list);
textView.setAdapter(adapter);
}
private static final String[] COUNTRIES = new String[] {
"Belgium", "France", "Italy", "Germany", "Spain"
};
I do not understand what the second parameter (android.R.layout.simple_dropdown_item_1line) in the constructor of ArrayAdapter means, where does this come from?
Is it a layout which is available from android or do I have to replace this layout with a layout created on my own and how to define this layout file in that case?
Concrete my code lokks like
xml:
<AutoCompleteTextView
android:id="#+id/search"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
java:
AutoCompleteTextView search =(AutoCompleteTextView) findViewById(R.id.search);
String[] vocabs = new String[1001];
//fill the String array
ArrayAdapter<String> adapter = new ArrayAdapter<>(this, android.R.layout.simple_dropdown_item_1line ,vocabs);
search.setAdapter(adapter);

They are calling the constructor of ArrayAdapter with 3 arguments (documentation): ArrayAdapter(Context context, int resource, T[] objects)
The resource R.layout.simple_dropdown_item_1line is just one of the default android framework layouts for dropdowns. See here a list of other default layouts.
EDIT to answer your 2nd question:
You can either use the default android layout (the example you provided should work) or a custom one defined by you. If it's this last case then just create a xml layout for this layout:
layouts/dropdown_custom_view.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:id="#+id/vocab_text"
android:layout_width="match_parent"
android:layout_height="wrap_content"
tools:text="vocab"/>
</LinearLayout>
Then you can use the ArrayAdapter constructor ArrayAdapter(Context context, int resource, int textViewResourceId, T[] objects) pointing to your custom layout and to the TextView you want to be populated with vocabs:
ArrayAdapter<String> adapter = new ArrayAdapter<>(this, R.layout.dropdown_custom_view, R.id.vocab_text ,vocabs);
search.setAdapter(adapter);
Also check that you're populating the vocabs array well.

This layout which is available within Android System that's the reason you use android.R.It is used to show an item from the array adapter.It is basically a textview with some styling

You can use the custom layout for AutoCompleteTextView like
ArrayAdapter<String> adapter =
new ArrayAdapter<String>(this, R.layout.custom_layout, R.id.text_title, COUNTRIES);
AutoCompleteTextView textView = (AutoCompleteTextView) findViewById(R.id.countries_list);
textView.setAdapter(adapter);
custom_layout.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#e4e4e4"
>
<TextView
android:id="#+id/text_title"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ellipsize="marquee"
tools:text="AA"
android:padding="15dp"
/>
</LinearLayout>

Adding a header/TextView above 2 list views

I have a Java class and two XML files which are basically just a side by side listView which takes in some values. I want to put a header or a text view above each list view ( they should stay side by side ) however every time I try to add a textView the whole project messes up and following online instructions is not working to implement a header.
public class Leaderboard extends AppCompatActivity {
private ListView UsernameList;
private ListView ScoreList;
LocalDatabase localDatabase;
/** Called when the activity is first created */
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_leaderboard);
ArrayAdapter<String> listAdapter;
ArrayAdapter<Integer> list2Adapter;
//Find the ListView resources
UsernameList = (ListView) findViewById(R.id.UsernameList);
ScoreList = (ListView) findViewById(R.id.ScoreList);
//Create and populate the list of usernames.
//This is where the information from the Database would need to be entered. and the String[] removed
String[] usernames = new String[]{"Andy", "Marie", "George"};
ArrayList<String> usernameList = new ArrayList<String>();
usernameList.addAll(Arrays.asList(usernames));
//Create and populate the list of scores
//This is where the information from the Database would need to be entered. and the Integer[] removed
Integer[] scores = new Integer[]{7, 4, 1};
ArrayList<Integer> scoreList = new ArrayList<Integer>();
scoreList.addAll(Arrays.asList(scores));
//adds the users details to the leaderboard
localDatabase = new LocalDatabase(this);
Contact contact = localDatabase.getLoggedInUser();
//Set a string to have the value of the users name.
String s = contact.name;
//Create Array Adapter using the username list
listAdapter = new ArrayAdapter<String>(this, R.layout.activity_row, usernameList);
//Add more users
listAdapter.add(s);
//Set the Array Adapter as the ListView's adapter
UsernameList.setAdapter(listAdapter);
//Create Array Adapter using the username list
list2Adapter = new ArrayAdapter<Integer>(this, R.layout.activity_row, scoreList);
//Add more users
list2Adapter.add(0);
//Set the Array Adapter as the ListView's adapter
ScoreList.setAdapter(list2Adapter);
}
}
Then the two xml files
<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:background="#color/colorPrimaryDark"
android:id="#+id/rowTextView"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textColor="#color/white"
android:textStyle="bold"
android:padding="10dp"
android:textSize="16sp">
</TextView>
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:background="#color/colorPrimaryDark"
android:layout_height="fill_parent"
android:padding="20dp"
android:orientation="horizontal"
tools:context=".Leaderboard">
<ListView
android:id="#+id/UsernameList"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_margin="2dp"
android:layout_weight=".60"
android:drawSelectorOnTop="false"
android:headerDividersEnabled="false">
</ListView>
<ListView
android:id="#+id/ScoreList"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_margin="2dp"
android:layout_weight=".40">
</ListView>
</LinearLayout>

Try encapsulating the two TextViews in a LinearLayout. The linear Layout should span the entire width (match_parent), but only be as high as need be; wrap_content.
What you then want to do to have them neatly divided amongst the width of the screen, is, first off, set the LinearLayout orientation to horizontal. Then, you make the width of and both TextViews 0dp (that's right, 0dp), and their height wrap_content. Then, give both TextViews a weight of 1. The views now both take up half the space (in width) of the LinearLayout. Finally, centre the TextViews for a good looking header.
Ive kept it very broad and non-codey, but I think you should be able to google all the concepts explained above if you run into any trouble. If you really cant figure it out,i'll help you out in the comments.

How can I add a text view for every item in my list?

I am making a yelp-like app in which users can leave reviews for various places, but I want other users to be able to see all of the reviews left. Currently, I am using a list to store all of my reviews in, but I can't seem to figure out how I can make a textview for each item in the list, seeing as the length of the list may vary. Also, piggy backing on this question, would there be anyway to format the textview (i.e. layoutbelow or margins)?
Thanks in advance,
Jacob

Should be able to do this with an adapter and listview:
Activity.java:
public class YourActivity extends Activity
{
ArrayList<String> reviewsArray = new ArrayList<String>();
ListView reviewList;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.youractivity);
reviewList = (ListView) findViewById(R.id.yourListViewId);
//fill your reviewsArray...
ArrayAdapter<String> reviewsAdapter = new ArrayAdapter<String>(context, R.layout.reviewLayout, reviewsArray);
reviewsList.setAdapter(reviewsAdapter);
}
}
activity_layout.xml: (change size of the listview here)
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<ListView
android:id="#+id/yourListViewId"
android:layout_height="wrap_content"
android:layout_width="match_parent">
</ListView>
</LinearLayout>
reviewLayout.xml (change the reviews padding etc here)
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+android:id/gridCell"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:minHeight="?android:attr/listPreferredItemHeight"
android:paddingStart="1dp"
android:paddingEnd="1dp"
android:textAppearance="?android:attr/textAppearanceSmall" />
Without seeing your code it's hard to give you an exact example, but this contains all the basics.

Custom ListView TextView Items all show gray bar at top

I'm having a problem with a custom ListView I am using in the ListActivity of my application. My problem is that all TextView items added to the ListView through an ArrayAdapter show up with a gray bar above them. I would include an image of the displayed ListView, but am unable since I do not have a reputation of 10 required by the stackoverflow site.
The layout file (index.xml) used to produce the ListView is defined as follows:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_height="fill_parent"
android:layout_width="fill_parent"
android:orientation="vertical" >
<ListView
android:divider="#color/mg_red"
android:dividerHeight="1sp"
android:id="#android:id/list"
android:layout_height="fill_parent"
android:layout_width="fill_parent" />
<TextView
android:title="text_view"
android:background="#drawable/listitemback"
android:cacheColorHint="#drawable/listitemback"
android:id="#+id/listItem"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="10sp"
android:textColor="#color/listitemtext"
android:textSize="16sp" />
</LinearLayout>
The ListActivity code used to display the list is as follows:
public class IndexListActivity extends ListActivity
{
private ListView m_listView = null;
#Override
public void onCreate(Bundle savedInstanceState)
{
try
{
if (MGApplication.DEBUG_BUILD)
Log.i("TMG", "IndexListActivity.onCreate");
super.onCreate(savedInstanceState);
// Get our global data object.
MGApplication mgApp = (MGApplication) getApplication();
// Set view layout
SetContentView(R.layout.index);
// Get references to our ListView and AdView objects
m_listView = (ListView) findViewById(android.R.id.list);
// Create a new ArrayAdapter object that will be used to initialize
// the underlying ListView object.
ArrayAdapter<String> aa = new ArrayAdapter<String>(this, R.layout.index,
R.id.listItem,
mgApp.m_strAZRhymeNames);
// Assign array adapter
m_listView.setAdapter(aa);
}
catch (Exception e)
{
}
return;
}
}
Any help is greatly appreciated as I am at my wits end with this issue. I think I've tried every suggestion I could find on the web and I am unable to remove the gray bar.
Thank You,
Bob

you have to set this property in test.xml file with.
<ListView
android:id="#+id/listview_middle"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_margin="1dip"
android:layout_weight="1"
android:background="#ffffff"
android:cacheColorHint="#android:color/transparent"
android:choiceMode="singleChoice"
android:scrollingCache="false" />
and set some property in listview object.
lv.setVerticalFadingEdgeEnabled(false);
In my side that's work perfect.

How to create an ListView without ListActivity

Someone could tell me how can I create a ListView without using a ListActivity?
I need to put in my layout several other views, and I wish the layout was not fully occupied by the ListView. It must be part of the layout, not the entire layout. I want to create a normal Activity.
Code snippet:
protected void onCreate(Bundle savedInstanceState) {
setContentView(R.layout.savings);
//...
ListView lvPoupanca = (ListView)this.findViewById(R.id.lvPoupanca);
// the adapter
TestRepository repo = new TestRepository(this);
Cursor c = repo.getCursor();
SimpleCursorAdapter adapter = new SimpleCursorAdapter(this, R.layout.list_item, c, new String[]{"Nome", "ValorAtual"}, new int[] {R.id.tvNome, R.id.tvValorTotal});
lvPoupancas.setAdapter(adapter);
// ...
}
Edit:
The saving.xml file:
<?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="fill_parent"
android:orientation="vertical" >
<ListView
android:id="#+id/lvPoupancas"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
>
</ListView>
</LinearLayout>
Hope somebody can help me.
Thanks and sorry about my bad english.

Like with any other View in any Activity...
ListView l = new ListView(this);
// OR
ListView l = (ListView) findViewById(R.id...);
...
l.setAdapter(...);
// If using first way: setContentView(l);
For example

I have replied to a similar question before. But that was in a different context. So, I'm putting some reference code here. It will help you to fix the issue.
public class ListandtextActivity extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final String [] str = {"ONE","TWO","THREE"};
final ListView lv = (ListView) findViewById(R.id.listView1);
final TextView tv = (TextView)findViewById(R.id.tv1);
ArrayAdapter<Object> adapt = new ArrayAdapter<Object>(getApplicationContext(), android.R.layout.simple_list_item_1, str);
lv.setAdapter(adapt);
lv.setOnItemClickListener(new OnItemClickListener(){
#Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
tv.setText("You Clicked Something");
}
});
}
}
And the XML is
<?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="fill_parent"
android:orientation="vertical" >
<ListView
android:id="#+id/listView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1" >
</ListView>
<TextView
android:id="#+id/tv1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="#string/hello" android:textSize="20dip"/>
</LinearLayout>
By the way, before asking questions, collect as much information as possible for others to help you. If it does not work, it will be better to put the error log in the question rather than just saying it does not work.

Don't Extend ListActivity then. Extend an Activity and in onCreate() put the following code as per your requirement.
setContentView(R.layout.ur_xml);
Listview list = (ListView)findViewById(R.id.lvPoupancas);
list.setAdapter(your Adapter);