I am trying to add items to a ListView/Adapter from my MainActivity and use it across ListHelper.
I have it declared in Registrant.
public static List<Registrant> searchList = new ArrayList<Registrant>();
And then I add to it from MainActivity..
Registrant.searchList.add(registrant);
Then I try to retrieve this into a listview from the ListHelper.
ListView listView = (ListView) findViewById(R.id.list);
listView.setAdapter(adapter);
adapter = new CustomListAdapter(this, Registrant.searchList);
adapter.notifyDataSetChanged();
But no luck, it is a blank screen?
Any ideas would be helpful.. thank you!
Instead of creating object of CustomListAdapter class for updating data in ListView data-source. create a method in CustomListAdapter class for adding data in List which is used by Adapter as data-source :
In CustomListAdapter class add following method:
public void addItems(){
arrList.addAll(Registrant.searchList);
this.notifyDataSetChanged();
}
Now call addItems method when want to update data in ListView:
listView.setAdapter(adapter);
adapter.addItems();
Related
Move your adapter initialization inside onCreate. You need to set the adapter to the ListView using setAdapter. Call noftifyDataSetChanged after populating the dataset arr.
Try this code,
private MyAdapter ma;
onCreate(){
...
setContentView(R.layout.activty_main2);
lv = (ListView) findViewById(R.id.lv_1);
ma = new MyAdapter(this, arr);
lv.setAdapter(ma);
initData();
}
initData(){
for(;;){
...
arr.add(n);
}
ma.noftifyDataSetChanged();
}
You not having any blank constructor in MyAdapter,
you have to pass context and ArrayList to the adapter like,
MyAdapter ma = new MyAdapter(Main2Activity.this,arr);
I am curious how I would go about adding an an editText variable to a list in another activity. I have created an arrayList that names are stored into as they are entered in the editText line. These are stored in the nameList variable in the class StartingActivity. How would i go about adding and showing these names into a ListView in another activity and class called ListActivity as shown. Thank you. Also, how do i refractor the names of classes and files without it just basically not making my program runable.
Code:
Class StartingActivity:
public void onClick_btnConfirm {
EditText editName = (EditText) findViewById(R.id.editName);
TextView textOutput = (TextView) findViewById(R.id.textOutput);
Intent intentList = new Intent(StartingActivity.this, ListActivity.class);
if(editName.length()!=0) {
nameList.add(editName.getText().toString());
editName.setText("");
}
//intentList.putExtra("Name", editName.toString());
startActivity(intentList);
}
Class ListActivity:
public class ListActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list);
ListView listView = (ListView) findViewById(R.id.listAthletes);
final StartingActivity nameList = new StartingActivity();
nameList.getNameList();
ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, nameList.getNameList());
listView.setAdapter(arrayAdapter);
arrayAdapter.notifyDataSetChanged();
}
}
You cannot run findviewbyid() for an id in another Activity.This answer might be of help to you. If that is not what you really want to go with, you can do two things:
Send Intents with the string.
Use a sharedPreference and write the string to a sharedPreference. SharedPreferences also have an OnChangeListener, so you will be able know if the preference has changed. In the onResume() of that activity , you can just read from the sharedPreference, and update the UI
Also take a look at AsyncTask here
As mentioned , you can also use the SQLite Database
I have made a simple contact apps and now I wish to add tab view to this app. I am following the tutorial here. Below is part of the source code for my MainActivity.jave:
public class MainActivity extends ListActivity {
private ListView contactListView;
private CursorAdapter contactListViewAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
contactListView = getListView(); // get ListView id
contactListView.setOnItemClickListener(viewContactListListener);
String[] from = new String[] { "familyName" }; // built an String array
// named "from"
int[] to = new int[] { R.id.contactTextView };
contactListViewAdapter = new SimpleCursorAdapter(MainActivity.this,
R.layout.contact_list_item, null, from, to);
setListAdapter(contactListViewAdapter); // set adapter
}
I tried to change "public class MainActivity extends ListActivity" to "public class MainActivity extends TabActivity implements OnTabChangeListener{". However, I get the error "The method getListView() is undefined for the type MainActivity" and other similar errors. I need suggestions on how to fix this. Thanks for any help.
ListActivity provides some help methods to manage ListView so if you want to change your parent activity from ListActivity to TabActivity you need to handle ListActivity behaviour yourself.
Basically you need to get and store somewhere the ListView object. Something like mListView = (ListView) findViewById(android.R.id.list) on your onCreate method and then implement missing method
ListView getListView()
{
return mListView;
}
Also setting your adapter will be a bit different. Instead of calling setListAdapter(contactListViewAdapter); // set adapter there should be contactListView.setAdapter(contactListViewAdapter);
I am trying to add a two-column ListView to my android app. When I created the project, I selected the option Fragment which creates that beautiful navigation by sliding to left and right. So my MainActivity extends FragmentActivity.
my problem is when I am trying to add AddayAdapter to ListView, the construstor of ArrayAdapter looks for a context object and I dont know to pass that.
here is the code where I get error
StableArrayAdapter adapter = new StableArrayAdapter(this, R.layout.row , list);
listview.setAdapter(adapter);
When I pass "this", it passes FragmentActivity because the activity extends FragmentActivity. but constructor need a "Context" object.
it gives this error message
"The constructor MainActivity.StableArrayAdapter(MainActivity.DummySectionFragment, int, ArrayList<String>) is undefined"
How can I pass Context object?
You are setting the adapter inside a fragment. Use
StableArrayAdapter adapter = new StableArrayAdapter(this.getActivity(), R.layout.row , list);
StableArrayAdapter adapter = new StableArrayAdapter(getContext(), R.layout.row , list);
listview.setAdapter(adapter);
Did you try passing something like this from your Fragment. Try either getContext() or getApplicationContext().
I have following code:
public class ShowActivity extends ListActivity implements OnItemClickListener {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// setContentView(R.layout.show_list);
ListView lv = getListView();
String[] projection = new String[]{
BaseColumns._ID,
DepotTableMetaData.ITEM_NAME,
DepotTableMetaData.ITEM_AMOUNT,
DepotTableMetaData.ITEM_UNIT,
DepotTableMetaData.ITEM_PPU,
DepotTableMetaData.ITEM_TOTAL,
DepotTableMetaData.ITEM_COMMENT};
Cursor c = managedQuery(ContentProviderMetaData.DepotTableMetaData.CONTENT_URI, projection, null, null, ContentProviderMetaData.DepotTableMetaData.DEFAULT_SORT_ORDER);
String[] columns = new String[]{BaseColumns._ID,ContentProviderMetaData.DepotTableMetaData.ITEM_NAME, ContentProviderMetaData.DepotTableMetaData.ITEM_AMOUNT, ContentProviderMetaData.DepotTableMetaData.ITEM_UNIT, ContentProviderMetaData.DepotTableMetaData.ITEM_PPU, ContentProviderMetaData.DepotTableMetaData.ITEM_TOTAL, ContentProviderMetaData.DepotTableMetaData.ITEM_COMMENT};
int[] to = new int[]{R.id.lname,R.id.lamount,R.id.lunit,R.id.lppu,R.id.ltotal,R.id.lcomment};
Log.d("ShowActivity","Cursor, columns, to set - now setting adapter");
SimpleCursorAdapter simpleadapter = new SimpleCursorAdapter(this,R.layout.list_entry, c, columns, to);
// ListView lv = (ListView)findViewById(R.id.ListView);
this.setListAdapter(simpleadapter);
lv.setOnItemClickListener(this);
// intentCheck();
}
It works fine, but as you might have seen at my comments, i don't want to create the listview via getListView(), i want to do a usual setContentView(R.Layout.---) and populate a Listview, which is defined there. But all tutorials I have seen yet do it like that, and I have no clue how to change that to my wishes.
How does my layout-xml have to look like? how do i "tell him to use it" ?
Thanks in advance.
You can use directly setContentView(R.layout.main); on a ListActivity as long as you define a listView with the android:list id on your xml:
<ListView android:id="#+id/android:list"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>
To set the adapter call directly setListAdapter from your ListActivity
Don't use ListActivity as your base class, extend Activity, set your content to the layout, grab a reference to your expanded ListView (findViewById(...)) and then handle setting the adapter that way.
ListView lv = (ListView)findViewById(android.R.id.list);
No change needed in the .xml