I have a dialog in Android, as a layout I use this file:
<?xml version="1.0" encoding="utf-8"?> <ListView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
</ListView>
In the Activity I need to add a Adapter to this ListView, I have this:
#Override
protected Dialog onCreateDialog(int id) {
switch(id){
case ADDPLAYERDIALOG:{
Dialog d = new Dialog(this);
d.setContentView(R.layout.training_dialog);
ListView lv = (ListView) d.getCurrentFocus().getRootView();
ListAdapter adapter = new ArrayAdapter<String>(getBaseContext(), android.R.layout.simple_list_item_1, createNamesList());
lv.setAdapter(adapter);
return d;
}
}
return super.onCreateDialog(id);
}
I get a NullPointerException here:
ListView lv = (ListView) d.getCurrentFocus().getRootView();
I don't have the id for this ListView widget, because it is a layout XML-file, and I can't just write lv = d.findViewById(R.id.listview);
How can I solve the problem?
You can easily set an id through xml. You use the android:id tag.
Your listview node should look something like this:
<ListView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id = "#+id/listview">
</ListView>
Now your lv = d.findViewById(R.id.listview); should work.
Related
I am getting an error when trying to set my view to display the ListView for the file I want to display(text file). I am pretty sure it has something to do with the XML. I just want to display the information from this.file = fileop.ReadFileAsList("Installed_packages.txt");. My code:
public class Main extends Activity {
private TextView tv;
private FileOperations fileop;
private String[] file;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.fileop = new FileOperations();
this.file = fileop.ReadFileAsList("Installed_packages.txt");
setContentView(R.layout.main);
tv = (TextView) findViewById(R.id.TextView01);
ListView lv = new ListView(this);
lv.setTextFilterEnabled(true);
lv.setAdapter(new ArrayAdapter<String>(this, R.layout.list_item, this.file));
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
// When clicked, show a toast with the TextView text
Toast.makeText(getApplicationContext(), ((TextView) view).getText(), Toast.LENGTH_SHORT).show();
}
});
setContentView(lv);
}
}
list_item.xml :
<?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"
android:padding="10dp"
android:textSize="16sp"
android:textColor="#000">
</LinearLayout>
main.xml :
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:weightSum="1">
<ScrollView
android:id="#+id/SCROLLER_ID"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:scrollbars="vertical"
android:fillViewport="true">
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:padding="5sp"
android:id="#+id/TextView01"
android:text="#string/hello"/>
</ScrollView>
</LinearLayout>
The ArrayAdapter requires the resource ID to be a TextView XML exception means you don't supply what the ArrayAdapter expects. When you use this constructor:
new ArrayAdapter<String>(this, R.layout.a_layout_file, this.file)
R.Layout.a_layout_file must be the id of a xml layout file containing only a TextView(the TextView can't be wrapped by another layout, like a LinearLayout, RelativeLayout etc!), something like this:
<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
// other attributes of the TextView
/>
If you want your list row layout to be something a little different then a simple TextView widget use this constructor:
new ArrayAdapter<String>(this, R.layout.a_layout_file,
R.id.the_id_of_a_textview_from_the_layout, this.file)
where you supply the id of a layout that can contain various views, but also must contain a TextView with and id(the third parameter) that you pass to your ArrayAdapter so it can know where to put the Strings in the row layout.
Soution is here
listitem.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="#+id/textview"
android:layout_width="match_parent"
android:layout_height="match_parent" >
</TextView>
</LinearLayout>
Java code :
String[] countryArray = {"India", "Pakistan", "USA", "UK"};
ArrayAdapter adapter = new ArrayAdapter<String>(this, R.layout.listitem,R.id.textview, countryArray);
ListView listView = (ListView) findViewById(R.id.listview);
listView.setAdapter(adapter);
If you are getting that message when you are extending an ArrayAdapter, you are getting that error because you have not provided the correct resource id to display the item. Call the super class in the constructor and pass in the resource id of the TextView:
//Pass in the resource id: R.id.text_view
SpinnerAdapter spinnerAddToListAdapter = new SpinnerAdapter(MyActivity.this,
R.id.text_view,
new ArrayList<>());
Adapter:
public class SpinnerAdapter extends ArrayAdapter<MyEntity> {
private Context context;
private List<MyEntity> values;
public SpinnerAdapter(Context context, int textViewResourceId,
List<MyEntity> values) {
//Pass in the resource id: R.id.text_view
super(context, textViewResourceId, values);
this.context = context;
this.values = values;
}
The problem is in the line:
lv.setAdapter(new ArrayAdapter<String>(this, R.layout.list_item, this.file));
Because when i change it to:
lv.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, this.file));
It works!
I want to show a list of cars in an Android Dialog and it keeps showing nothing.
Note: purchasedCars.getCars() is not empty
Here is the code:
findViewById(R.id.buy).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
AlertDialog.Builder builder = new AlertDialog.Builder(BuyCarActivity.this);
View dialogView=getLayoutInflater().inflate(R.layout.dialog_list,null);
builder.setView(dialogView);
ListView listView = dialogView.findViewById(R.id.listView2);
listView.setAdapter(new ArrayAdapter<>(view.getContext(), android.R.layout.simple_list_item_1, purchasedCars.getCars()));
builder.show();
}
});
check your inflated layout its seems to look like this one
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<ListView
android:id="#+id/listView2"
android:layout_width="match_parent"
android:layout_height="match_parent">
</ListView>
</LinearLayout>
and can you test if you change purchasedCars.getCars()
to - > new String[]{"test","app"}
for example
listView.setAdapter(new ArrayAdapter<>(view.getContext(), android.R.layout.simple_list_item_1, new String[]{"test","app"}));
OR
List<String> list = new ArrayList<>();
list.add("test");
list.add("app");
listView.setAdapter(new ArrayAdapter<>(view.getContext(), android.R.layout.simple_list_item_1, list));
check if thats work if yes .. you need to take a look for what purchasedCars.getCars() return .
I am getting an error when trying to set my view to display the ListView for the file I want to display(text file). I am pretty sure it has something to do with the XML. I just want to display the information from this.file = fileop.ReadFileAsList("Installed_packages.txt");. My code:
public class Main extends Activity {
private TextView tv;
private FileOperations fileop;
private String[] file;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.fileop = new FileOperations();
this.file = fileop.ReadFileAsList("Installed_packages.txt");
setContentView(R.layout.main);
tv = (TextView) findViewById(R.id.TextView01);
ListView lv = new ListView(this);
lv.setTextFilterEnabled(true);
lv.setAdapter(new ArrayAdapter<String>(this, R.layout.list_item, this.file));
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
// When clicked, show a toast with the TextView text
Toast.makeText(getApplicationContext(), ((TextView) view).getText(), Toast.LENGTH_SHORT).show();
}
});
setContentView(lv);
}
}
list_item.xml :
<?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"
android:padding="10dp"
android:textSize="16sp"
android:textColor="#000">
</LinearLayout>
main.xml :
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:weightSum="1">
<ScrollView
android:id="#+id/SCROLLER_ID"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:scrollbars="vertical"
android:fillViewport="true">
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:padding="5sp"
android:id="#+id/TextView01"
android:text="#string/hello"/>
</ScrollView>
</LinearLayout>
The ArrayAdapter requires the resource ID to be a TextView XML exception means you don't supply what the ArrayAdapter expects. When you use this constructor:
new ArrayAdapter<String>(this, R.layout.a_layout_file, this.file)
R.Layout.a_layout_file must be the id of a xml layout file containing only a TextView(the TextView can't be wrapped by another layout, like a LinearLayout, RelativeLayout etc!), something like this:
<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
// other attributes of the TextView
/>
If you want your list row layout to be something a little different then a simple TextView widget use this constructor:
new ArrayAdapter<String>(this, R.layout.a_layout_file,
R.id.the_id_of_a_textview_from_the_layout, this.file)
where you supply the id of a layout that can contain various views, but also must contain a TextView with and id(the third parameter) that you pass to your ArrayAdapter so it can know where to put the Strings in the row layout.
Soution is here
listitem.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="#+id/textview"
android:layout_width="match_parent"
android:layout_height="match_parent" >
</TextView>
</LinearLayout>
Java code :
String[] countryArray = {"India", "Pakistan", "USA", "UK"};
ArrayAdapter adapter = new ArrayAdapter<String>(this, R.layout.listitem,R.id.textview, countryArray);
ListView listView = (ListView) findViewById(R.id.listview);
listView.setAdapter(adapter);
If you are getting that message when you are extending an ArrayAdapter, you are getting that error because you have not provided the correct resource id to display the item. Call the super class in the constructor and pass in the resource id of the TextView:
//Pass in the resource id: R.id.text_view
SpinnerAdapter spinnerAddToListAdapter = new SpinnerAdapter(MyActivity.this,
R.id.text_view,
new ArrayList<>());
Adapter:
public class SpinnerAdapter extends ArrayAdapter<MyEntity> {
private Context context;
private List<MyEntity> values;
public SpinnerAdapter(Context context, int textViewResourceId,
List<MyEntity> values) {
//Pass in the resource id: R.id.text_view
super(context, textViewResourceId, values);
this.context = context;
this.values = values;
}
The problem is in the line:
lv.setAdapter(new ArrayAdapter<String>(this, R.layout.list_item, this.file));
Because when i change it to:
lv.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, this.file));
It works!
I am getting an error when trying to set my view to display the ListView for the file I want to display(text file). I am pretty sure it has something to do with the XML. I just want to display the information from this.file = fileop.ReadFileAsList("Installed_packages.txt");. My code:
public class Main extends Activity {
private TextView tv;
private FileOperations fileop;
private String[] file;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.fileop = new FileOperations();
this.file = fileop.ReadFileAsList("Installed_packages.txt");
setContentView(R.layout.main);
tv = (TextView) findViewById(R.id.TextView01);
ListView lv = new ListView(this);
lv.setTextFilterEnabled(true);
lv.setAdapter(new ArrayAdapter<String>(this, R.layout.list_item, this.file));
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
// When clicked, show a toast with the TextView text
Toast.makeText(getApplicationContext(), ((TextView) view).getText(), Toast.LENGTH_SHORT).show();
}
});
setContentView(lv);
}
}
list_item.xml :
<?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"
android:padding="10dp"
android:textSize="16sp"
android:textColor="#000">
</LinearLayout>
main.xml :
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:weightSum="1">
<ScrollView
android:id="#+id/SCROLLER_ID"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:scrollbars="vertical"
android:fillViewport="true">
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:padding="5sp"
android:id="#+id/TextView01"
android:text="#string/hello"/>
</ScrollView>
</LinearLayout>
The ArrayAdapter requires the resource ID to be a TextView XML exception means you don't supply what the ArrayAdapter expects. When you use this constructor:
new ArrayAdapter<String>(this, R.layout.a_layout_file, this.file)
R.Layout.a_layout_file must be the id of a xml layout file containing only a TextView(the TextView can't be wrapped by another layout, like a LinearLayout, RelativeLayout etc!), something like this:
<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
// other attributes of the TextView
/>
If you want your list row layout to be something a little different then a simple TextView widget use this constructor:
new ArrayAdapter<String>(this, R.layout.a_layout_file,
R.id.the_id_of_a_textview_from_the_layout, this.file)
where you supply the id of a layout that can contain various views, but also must contain a TextView with and id(the third parameter) that you pass to your ArrayAdapter so it can know where to put the Strings in the row layout.
Soution is here
listitem.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="#+id/textview"
android:layout_width="match_parent"
android:layout_height="match_parent" >
</TextView>
</LinearLayout>
Java code :
String[] countryArray = {"India", "Pakistan", "USA", "UK"};
ArrayAdapter adapter = new ArrayAdapter<String>(this, R.layout.listitem,R.id.textview, countryArray);
ListView listView = (ListView) findViewById(R.id.listview);
listView.setAdapter(adapter);
If you are getting that message when you are extending an ArrayAdapter, you are getting that error because you have not provided the correct resource id to display the item. Call the super class in the constructor and pass in the resource id of the TextView:
//Pass in the resource id: R.id.text_view
SpinnerAdapter spinnerAddToListAdapter = new SpinnerAdapter(MyActivity.this,
R.id.text_view,
new ArrayList<>());
Adapter:
public class SpinnerAdapter extends ArrayAdapter<MyEntity> {
private Context context;
private List<MyEntity> values;
public SpinnerAdapter(Context context, int textViewResourceId,
List<MyEntity> values) {
//Pass in the resource id: R.id.text_view
super(context, textViewResourceId, values);
this.context = context;
this.values = values;
}
The problem is in the line:
lv.setAdapter(new ArrayAdapter<String>(this, R.layout.list_item, this.file));
Because when i change it to:
lv.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, this.file));
It works!
I'm new to android, I want to use my custom layout file instead of simple_list_item_1 but its not allowing to do so. I want to add an backgroud image(which is defined in layout->custom_view.xml) to each items in the list OR help me to set the backgroud for the whole page, In the below code where should I use the setContentView Method. Also let me know if any changes are to be made in the below .xml file.
public class Planet extends ListActivity {
#Override
public void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);
//setContentView(R.layout.custom_view); Tried to set the view from here but the application is crashing...
String[] planet_names = new String[] {"Mercury","Venus","Earth","Mars","Jupiter","Saturn","Uranus","Neptune","Sun"};
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, planet_names);
setListAdapter(adapter);
ListView lv = getListView();
lv.setTextFilterEnabled(true);
lv.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
if(position == 0)
{
Intent myIntent = new Intent(Planet.this, Galaxy.class);
startActivityForResult(myIntent, 0);
}
}
});
}
custom_view.xml file is as follows,
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#FFFFFF">
<ListView
android:id="#+id/listView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent" />
</LinearLayout>
Simply use this
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, R.layout.yourcustomview_withonetextview,R.id.yourcustomlayouttextviewid, planet_names);
You don't set the contentview in a ListActivity. The ListActivity already does that for you. Use an Activity, if you want to customize your layout.
You need to call super.onCreate() before setContentView(). And if you are going to use a custom layout in a ListActivity, you need to give the ListView the id #android:id/list.