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!
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 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 trying to implement a code in which a list of linear layouts are inserted in the list view by using the array adapter. Each linear layout contains two subviews. Here's the xml.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/list_item"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="#+id/list_icon"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="10dp"/>
<TextView
android:id="#+id/list_label"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_marginLeft="10dp"
android:padding="10dp"
android:textSize="16sp" />
</LinearLayout>
Now in the fragment I created a code snippet like this.
final String[] my_page_items = getResources().getStringArray(R.array.my_page_items);
int[] my_page_icons = {
R.mipmap.ic_about,
R.mipmap.ic_app_settings,
R.mipmap.ic_account_settings,
R.mipmap.ic_logout
};
LinearLayout[] items = new LinearLayout[my_page_items.length];
TextView[] labels = new TextView[my_page_items.length];
ImageView[] icons = new ImageView[my_page_icons.length];
for(int i=0; i<my_page_icons.length; i++) {
items[i] = (LinearLayout) LayoutInflater.from(getActivity().getApplication()).inflate(R.layout.list_item, null);
labels[i] = (TextView) items[i].findViewById(R.id.list_label);
icons[i] = (ImageView) items[i].findViewById(R.id.list_icon);
labels[i].setText(my_page_items[i]);
icons[i].setBackground(getResources().getDrawable(my_page_icons[i]));
}
setListAdapter(new ArrayAdapter<>(getActivity(), R.layout.list_item, items));
lv = getListView();
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
});
When I run this code, I get the the following in the logcat.
java.lang.IllegalStateException: ArrayAdapter requires the resource ID to be a TextView
How should this problem be solved?
In
new ArrayAdapter<>(getActivity(), R.layout.list_item, items)
R.Layout.list_item 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!),
EDIT possible solution :
If you want your list row layout to be something a little different then a simple TextView widget use this constructor:
new ArrayAdapter<>(getActivity(), R.layout.list_item, R.id.id_of_your_textview items)
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.
Im very new in android programming, and my task is to load up the items in my shared preference to a listview, and i just want to change the design of my listview, like changing its font color, font size and etc.. I have tried this solution but it doesn't work, please tell me where I did wrong. Thanks..
heres my code in loading the listview in a listactivity
Map<String,?> datakeys = datapref.getAll();
for(Map.Entry<String,?> entry : datakeys.entrySet()){
Log.d("values123",entry.getKey() + ": " + entry.getValue().toString());
lvlist.add(entry.getValue().toString());}
lvadapter = new ArrayAdapter<String>(this, R.layout.mytextview , R.id.text1, lvlist);
//lvadapter = new ArrayAdapter<String> (this,android.R.layout.simple_list_item_1,android.R.id.text1, lvlist);
setListAdapter(lvadapter);
heres the mytextview xml..
<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/text1"
android:paddingTop="2dip"
android:paddingBottom="3dip"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="10dip"
android:textColor="#666666"
android:textStyle="italic" />
and my listview xml
<ListView
android:id="#android:id/list"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_above="#+id/button3"
android:layout_alignParentLeft="true"
android:layout_below="#+id/textView3"
android:background="#b6fcd5" >
</ListView>
here's the screenshots
You need other constructor of ArrayAdapter :
public ArrayAdapter (Context context, int resource, int textViewResourceId, T[] objects)
so Change this line to :
lvadapter = new ArrayAdapter<String>(this, R.layout.mytextview, lvlist);
To :
lvadapter = new ArrayAdapter<String>(this, R.layout.mytextview , R.id.text1, lvlist);
And mytextview xml :
<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/text1"
android:paddingTop="2dip"
android:paddingBottom="3dip"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="10dip"
android:textColor="#666666"
android:textStyle="italic" />
If this doesn't work , then Go with Custom Adapter
one more approach: have a look
String [] yourStringarrayorlist= {"Lionssss","Cats", "yeaaahhh :)"};
ListView listView =new ListView(
getApplicationContext());
listView.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, yourStringarrayorlist) {
#Override
public View getView(int position, View convertView, ViewGroup parent) {
TextView textView = (TextView) super.getView(position, convertView, parent);
// if you want to change any specific items color
int textColor = textView.getText().toString().equals("Cats") ? R.color.any : android.R.color.black;
textView.setTextColor(VideoviewActivity.this.getResources().getColor(textColor));
//If you want to change the text color of all use below code
// textView.setTextColor(VideoviewActivity.this.getResources().getColor( R.color.any));
return textView;
}
});
layoutrela.addView(listView);
You can change the textcolor easily. However for just a check i've created ListView through code and added to the layout :) but it works like awesome..
Inspired by : How to change text color of simple list item
not a new answer so i would not expect any vote or so.
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!