Develop Reference

Passing List from 1st activity to 3rd activity

I have a splash screen activity(ACTIVITY A) which on load completion opens ACTIVITY B
ACTIVITY B ** consists of a button which opens **ACTIVITY C
ACTIVITY A loads a list using async task
I want this loaded list to be displayed in ACTIVITY C when opened
I have read many posts on how to pass values from 1st activity to 3rd activity and tried implementing all those but nothing helped
Evven tried passing the list object via intents from ACTIVITY A > ACTÌVITY B > ACTIVITY C but didnt work
Finally i have used " jacksons library " to convert the loaded list into a jsonstring then put it in sharedpreferences in ACTIVITY A , then retrive the jsonstring from sharedpreferences covert it back to list object in ** ACTIVITY C** and display the list
But the list is not getting displayed
What to do and is there any better process
splash activity(ACTIVITY A)
public class SplashActivity extends Activity{
List<ParseObject> ob;
List<CodeList> codelist = null;
ObjectMapper mapper;
SearchPreferences searchpref;
#Override
public void onCreate(Bundle savedInstanceState){
// TODO: Implement this method
super.onCreate(savedInstanceState);
setContentView(R.layout.splash);
mapper = new ObjectMapper();
searchpref = new SearchPreferences();
new DataTask().execute();
}
public class DataTask extends AsyncTask<Void, Void, List<CodeList>>{
#Override
protected List<CodeList> doInBackground(Void[] p1){
codelist = new ArrayList<CodeList>();
try {
ParseQuery<ParseObject> query = new ParseQuery<ParseObject>("InterActivity");
query.orderByAscending("_created_at");
ob = query.find();
for (ParseObject inter : ob) {
CodeList map = new CodeList();
map.setIntroduction((String) inter.get("intro"));
codelist.add(map);
}
return codelist;
}
catch (ParseException e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(List<CodeList> result){
try{
String jsonsearchlist = mapper.writeValueAsString(result);
Intent i = new Intent(SplashActivity.this, MainActivity.class);
searchpref.save(SplashActivity.this, jsonsearchlist);
startActivity(i);
}
catch (JsonProcessingException e){}
}
}
}
ACTIVITY C
public class SearchActivity extends Activity{
protected EditText searchedittext;
ImageButton searchButton;
List<ParseObject> ob;
List<CodeList> splashcodes;
FinalAdapter fnladapter;
SearchPreferences searchpref;
ObjectMapper mapper;
#Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.search_layout);
searchpref = new SearchPreferences();
mapper = new ObjectMapper();
String jsonsearchobj = searchpref.getValue(SearchActivity.this);
try{
splashcodes = (List<CodeList>) mapper.readValue(jsonsearchobj, CodeList.class);
final ListView searchedlist = (ListView) findViewById(R.id.searchlist);
fnladapter = new FinalAdapter(SearchActivity.this, splashcodes);
searchedlist.setAdapter(fnladapter);
}
catch (IOException e){}
}
}

You were on the right path: Loop your information through the 2nd activty. Please note, that CodeList must be serializable.
public class SplashActivity extends Activity{
...
protected void onPostExecute(ArrayList<CodeList> result){
Intent intent = new Intent(SplashActivity.this, SoCalledBActivity.class);
intent.putExtra("YOUR_UNIQUE_KEY",result);
this.startActivity(intent);
}
}
public class SoCalledBActivity extends Activity{
...
Button trigger = (Button) findViewById(R.id.trigger);
trigger.setOnClickListener(new Button.OnClickListener() {
public void onClick(View v) {
//get result list
ArrayList<CodeList> result = (ArrayList<CodeList>) this.getIntent().getExtras().get("YOUR_UNIQUE_KEY");
Intent intent = new Intent(SoCalledBActivity.this, SearchActivity .class);
//add list for C activity
intent.putExtra("YOUR_UNIQUE_KEY",result);
this.startActivity(intent);
}
});
public class SearchActivity extends Activity{
...
public void onCreate(Bundle savedInstanceState){
//extract list
ArrayList<CodeList> result = (ArrayList<CodeList>) this.getIntent().getExtras().get("YOUR_UNIQUE_KEY");
//do whatever you want with your list...
}
...
}

Create a global class and put that list in that class. Once you finish with filling the list, access the list data in Activity C.

How can initialized array became null?

Here is the code:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
overridePendingTransition(R.anim.fadein, R.anim.fadeout);
setContentView(R.layout.startpage);
rowItems = new ArrayList<RowItem>();
//... Filling this array.
}
Later, from another activity StartPage.rowItems.size() throw NullPointerException
It can be 0 (failed to retrieve data or I did .clear()), but how, the hell, it became null? I definitely never set it to null.
One more point - this array variable is public static and I use it from another activity. Can it be possible android unloads parent activity (what contains all global variables for the whole app)?
P.S. I cannot check it more thoroughly, because this error is not appears in my emulator/devices, but I got reported it on Google Play. So I can't check what was before and when the array became null...
Thank you
More exact code:
public class StartPage extends Activity implements View.OnTouchListener {
public static List<RowItem> rowItems;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
overridePendingTransition(R.anim.fadein, R.anim.fadeout);
setContentView(R.layout.startpage);
rowItems = new ArrayList<RowItem>();
pDialog = new ProgressDialog(this);
pDialog.setMessage("Loading data...");
pDialog.setCancelable(false);
pDialog.show();
gc=new GetData();gc.execute();
}
public class GetData extends AsyncTask<Void, Void, Void> {
#Override
protected void onPreExecute() {
super.onPreExecute();
rowItems.clear();
inProgress=true;
}
#Override
protected Void doInBackground(Void... arg0) {
ServiceHandler sh = new ServiceHandler();
String jsonStr = sh.makeServiceCall(url, ServiceHandler.GET);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
items = jsonObj.getJSONArray(TAG_COINS);
for (int i = 0; i < itemss.length(); i++) {
JSONObject c = items.getJSONObject(i);
String id = c.getString(TAG_ID).toUpperCase();
String price = c.getString(TAG_PRICE);
String name = c.getString(TAG_NAME);
RowItem item = new RowItem(id, name, price);
rowItems.add(item);
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.e("ServiceHandler", "Couldn't get any data from the url");
}
return null;
}
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
inProgress=false;
pDialog.dismiss();
}
}
Then call another activity:
public boolean onTouch(View view, MotionEvent event) {
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_UP:
int x = (int) event.getX();
int y = (int) event.getY();
int w=view.getWidth()-20;
int h=view.getHeight()-20;
if (x<w*0.05 || x>w*0.95 || y<h*0.13 ) return false; // Misclicked
if (x<w*0.5 && y<h*0.38) {
Intent intent = new Intent(this, MainActivity.class);
startActivity(intent);
}
}
return true;
}
On another activity (MainActivity), try to refresh the listview with the data from main activity:
public class MainActivity extends ListActivity implements View.OnClickListener {
void refresh_list() {
if (StartPage.rowItems.size()>0) { <-- Here is NPE
ListAdapter adapter = new CustomListAdapter(MainActivity.this,R.layout.list_item,StartPage.rowItems);
setListAdapter(adapter);
((BaseAdapter) getListAdapter()).notifyDataSetChanged();
}
}
Google play report:
Caused by: java.lang.NullPointerException
at halfprice.coinmanager.MainActivity.refresh_list(MainActivity.java:116)
at halfprice.coinmanager.MainActivity.onCreate(MainActivity.java:105)
at android.app.Activity.performCreate(Activity.java)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java)
Hope this helps...

you are loading your data in static ArrayList and Acessing it to different activity. its not good practice to do.
Let me first tell your answer as you have created this object in Oncreate(). Its better you make create it Globally than this problem will not occure.
Example :
public class StartPage extends Activity implements View.OnTouchListener {
public static List<RowItem> rowItems = new ArrayList<RowItem>();
OnCreate(){
//and perform the action you want to do.
}
//Hope this will help you definately.
Now Another Method which is the good Practice in Programming language
Passing data object from one Activity to another is simple, If you want to pass Array object than the object should be serialized. Eg;
ArrayList rowItems = new ArrayList();
for Passing array object you have to use intent PutExtra, Eg:
Intent intent = new Intent(SplashScreen.this, MainActivity.class);
intent.putExtra("key",array); startActivity(intent);
//intent.putExtra("key",array); will show error if your Model class is not implements Serializable eg: public class Model implements Serializable{
String id;
String price;
String name;
//generate your getter setter and set data in to this.
}
//For getting data in to another class just use
ArrayList<Model> data = (ArrayList<Model>)getIntent().getSerializable("key");
Now you can play arround with this data object. You should always try to play around with private or protected object.
Hope this will help you.

If i'm not mistaken:
When your activity is launched, the onCreate() method is called.
But when you come back to the same activity from another activity, then the onCreate method is skipped and onResume() method is called..so my suggestion is to initialize in the onResume() method
#Override
protected void onResume(Bundle savedInstanceState) {
overridePendingTransition(R.anim.fadein, R.anim.fadeout);
setContentView(R.layout.startpage);
rowItems = new ArrayList<RowItem>();
//... Filling this array.
}

This answer might not solve your current problem ( not enough code to give a suggestion) but will help you head in the right direction.
Do provide a central data store for your objects, you should consider using singleton design pattern. Also, since the data will be accessed from multiple threads, you should make the arraylist (in your case) thread safe.
Note: if you are using synchronized list, you should lock the object to prevent access when it is iterated.

Android - call OnSaveInstanceState from another class than main

I am creating some EditTexts with button, I created a class which implements OnClickListener, and I want to save those EditTexts after screen rotation but they always disappear. I know that
Activity on rotation is destroyed and created again
I cant save EditText in Bundle since it does not implement Parcelable or something like that
So I tried to save at least their ID's and Text they have in them with the onSaveInstanceState(Bundle savedInstanceState)
but it is not called because it is not in main class, but in another called ViewControl. I need to save some private variables (text and ids) so that is the reason why I have this method inside my class. I tried to call this method from another onSaveInstance which is in main but no luck neither. Can you tell me some easy way to programatically create EditTexts one below another and KEEP them after screen rotation? I really cant find any easy way...
Main class
public class MainActivity extends Activity {
private ViewControl vc;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
vc = new ViewControl(this);
}
#Override
public void onSaveInstanceState(Bundle savedInstanceState) {
super.onSaveInstanceState(savedInstanceState);
vc.onSaveInstanceState(savedInstanceState);
}
ViewControl class
import java.util.ArrayList;
public class ViewControl extends Activity implements View.OnClickListener{
private Button btn;
private RelativeLayout rl;
private Activity act;
private ArrayList<Integer> id;
private ArrayList<String> userpath;
private int lastId;
public ViewControl(Activity activity) {
this.act = activity;
this.id = new ArrayList<Integer>();
this.userpath = new ArrayList<String>();
this.rl = (RelativeLayout)act.findViewById(R.id.layout);
this.btn = (Button)act.findViewById(R.id.btn);
this.id.add(Integer.valueOf(R.id.btn));
this.btn.setOnClickListener(this);
}
#Override
public void onClick(View v) {
if(id.size() != 1)
lastId = id.get(id.size() - 1);
else
lastId = R.id.btn;
RelativeLayout.LayoutParams par = new RelativeLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
par.addRule(RelativeLayout.BELOW, lastId);
EditText et = new EditText(act);
et.setId(++lastId);
id.add(Integer.valueOf(lastId));
et.setText(Integer.toString(lastId));
rl.addView(et, par);
lastId = et.getId();
}
#Override
public void onSaveInstanceState(Bundle savedInstanceState) {
super.onSaveInstanceState(savedInstanceState);
savedInstanceState.putIntegerArrayList("ids", id);
savedInstanceState.putStringArrayList("userpaths", userpath);
savedInstanceState.putInt("lastId", lastId);
Toast.makeText(act, "Onsave", Toast.LENGTH_LONG).show();
}
#Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
this.id = savedInstanceState.getIntegerArrayList("ids");
this.userpath = savedInstanceState.getStringArrayList("userpaths");
this.lastId = savedInstanceState.getInt("lastId");
Toast.makeText(act, "Onrestore", Toast.LENGTH_LONG).show();
for(int i = 0; i < id.size(); i++)
{
RelativeLayout.LayoutParams par = new RelativeLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
par.addRule(RelativeLayout.BELOW, lastId);
EditText et = new EditText(act);
et.setId(this.id.get(i));
}
}
}

The calls are in the wrong order (both in MainActivity and ViewControl). First you should add your data, then pass the Bundle to super to save it (see the docs here). (Your onRestoreInstanceState is OK)

Easiest way to save data in savedInstanceState when managing an adapter(viewpager)

I'm working with an adapter(viewpager) and when the app changes orientation it loses its information. Which is the easiest way to conserve this information? I was going to use savedInstanceState inside the adapter but it doesn't recognise it.

Finally, I have done it following the advice of Jofre as he pointed in Activity restart on rotation Android
and looking in http://developer.android.com/intl/es/guide/topics/resources/runtime-changes.html
YOU MUST NOT MODIFY MANIFEST. DON'T ADD android:configChanges
SOLUTION:
//ALL THE VARIABLES YOU NEED TO SAVE IN YOUR ADAPTER PUT THEM AS PUBLIC, IE:
//public int a = 2;
//public String b = "a";
Public class Yourclass extends Activity{
Classofyouradapter adapter;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.yourlayout);
final Save_object data = (Save_object) getLastNonConfigurationInstance();
adapter = new Classofyouradapter(your variables);
if (data != null) {
fillit(data);
}
myPager = (ViewPager) findViewById(R.id.yourpanelpager);
myPager.setAdapter(adapter);
}
#Override
public Object onRetainNonConfigurationInstance() {
final Save_object data = new Save_object();
return data;
}
public class Save_object{
int a = adapter.a;
String b = adapter.b;
//Rest of variables
}
public void fillit(Save_object data){
adapter.a= data.a;
adapter.b= data.b;
//Rest of variables
}
}

keeping a variable value across all android activities

I have a database with one row of data that will be used across a number of activities. I need to be able to keep the row id available in all activites so I can read and write data across different activites with my DB adapter. I have successfully used putExtra (Overthelimit.java) via an intent to pass a row id to the next activity. mRowId variable is then given the row id using getExtra (Profile.java). The problem I now have is making mRowId available to other activities i.e. MyUsual and DrinksList so I can update data as I go.
You can see I have tried putExtras, putSerializable but can't get it to work. I think I am missing some understanding.
So for my profile menu option in the activity below I can send the value of the cursor row id to Profile class:
public class Overthelimit extends ListActivity {
private OverLimitDbAdapter dbHelper;
private Cursor cursor;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
this.getListView();
dbHelper = new OverLimitDbAdapter(this);
dbHelper.open();
fillData();
registerForContextMenu(getListView());
}
#Override
protected void onActivityResult(int requestCode, int resultCode,
Intent intent) {
super.onActivityResult(requestCode, resultCode, intent);
fillData();
}
private void fillData() {
cursor = dbHelper.fetchAllUserDrinks();
startManagingCursor(cursor);
//cursor.getCount();
String[] from = new String[] { OverLimitDbAdapter.KEY_USERNAME };
int[] to = new int[] { R.id.label };
// Now create an array adapter and set it to display using our row
SimpleCursorAdapter notes = new SimpleCursorAdapter(this,
R.layout.user_row, cursor, from, to);
setListAdapter(notes);
}
#Override
protected void onDestroy() {
super.onDestroy();
if (dbHelper != null) {
dbHelper.close();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.main_menu, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle item selection
switch (item.getItemId()) {
case R.id.profile:
Intent myIntent1 = new Intent(this, Profile.class);
if(cursor.getCount() != 0) {
//Toast.makeText(getApplicationContext(), "no profile",Toast.LENGTH_SHORT).show();
myIntent1.putExtra(OverLimitDbAdapter.KEY_ROWID, cursor.getString(cursor.getColumnIndexOrThrow(OverLimitDbAdapter.KEY_ROWID)));
}
startActivityForResult(myIntent1, 0);
return true;
case R.id.myusual:
Intent myIntent2 = new Intent(this, MyUsual.class);
startActivityForResult(myIntent2, 0);
return true;
case R.id.trackme:
Intent myIntent3 = new Intent(this, TrackMe.class);
startActivityForResult(myIntent3, 0);
return true;
case R.id.moreinfo:
Intent myIntent4 = new Intent(this, MoreInfo.class);
startActivityForResult(myIntent4, 0);
return true;
}
return super.onOptionsItemSelected(item);
}
}
Then make it available as mRowId in my Profile activity below:
mRowId = (bundle == null) ? null :
(Long) bundle.getSerializable(OverLimitDbAdapter.KEY_ROWID);
if (mRowId == null) {
Bundle extras = getIntent().getExtras();
mRowId = extras != null ? Long.parseLong(extras.getString(OverLimitDbAdapter.KEY_ROWID))
: null;
}
I then need to make this mRowId available to another activity called DrinkList from MyUsual. so I have MyUsual below with a drink1 button onClickListener to try and send the row id to DrinksList:
public class MyUsual extends Activity {
private Long mRowId;
private OverLimitDbAdapter mDbHelper;
private Cursor cursor;
private TextView mDrink1Label;
private TextView mDrink1Units;
/** Called when the activity is first created. */
#Override
public void onCreate(final Bundle bundle) {
super.onCreate(bundle);
mDbHelper = new OverLimitDbAdapter(this);
mDbHelper.open();
setContentView(R.layout.my_usual);
mDrink1Label = (TextView) findViewById(R.id.drink1Label);
mDrink1Units = (TextView) findViewById(R.id.drink1Units);
Button drink1 = (Button) findViewById(R.id.drink1Button);
// get intent data i.e. which drink button pressed and mRowId
mRowId = (bundle == null) ? null :
(Long) bundle.getSerializable(OverLimitDbAdapter.KEY_ROWID);
if (mRowId == null) {
Bundle extras = getIntent().getExtras();
mRowId = extras != null ? Long.parseLong(extras.getString(OverLimitDbAdapter.KEY_ROWID))
: null;
}
//populateFields();
drink1.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
setResult(RESULT_OK);
//finish();
Intent myIntent1 = new Intent(view.getContext(), DrinksList.class);
myIntent1.putExtra("drinkButton", "drink1");
if(cursor.getCount() != 0) {
myIntent1.putExtra(OverLimitDbAdapter.KEY_ROWID, cursor.getString(cursor.getColumnIndexOrThrow(OverLimitDbAdapter.KEY_ROWID)));
}
startActivityForResult(myIntent1, 0);
}
});
}
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
//saveState();
outState.putSerializable(OverLimitDbAdapter.KEY_ROWID, mRowId);
}
}
From DrinksList I select a drink and I need to use the mRowId write the data to the database via the onListItemclick:
public class DrinksList extends ListActivity {
private ProgressDialog m_ProgressDialog = null;
private ArrayList<CreateDrinkOption> m_drinks = null;
private DrinkAdapter m_adapter;
private Runnable viewDrinks;
private String drinkButton;
private Long mRowId;
private OverLimitDbAdapter mDbHelper;
private String databaseRow;
private Cursor cursor;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle bundle) {
super.onCreate(bundle);
setContentView(R.layout.drinks_list);
mDbHelper = new OverLimitDbAdapter(this);
mDbHelper.open();
m_drinks = new ArrayList<CreateDrinkOption>();
this.m_adapter = new DrinkAdapter(this, R.layout.drink_row, m_drinks);
setListAdapter(this.m_adapter);
viewDrinks = new Runnable(){
#Override
public void run() {
getDrinks();
}
};
Thread thread = new Thread(null, viewDrinks, "MagentoBackground");
thread.start();
m_ProgressDialog = ProgressDialog.show(DrinksList.this,
"Please wait...", "Retrieving data ...", true);
// get intent data i.e. which drink button pressed and mRowId
mRowId = (bundle == null) ? null :
(Long) bundle.getSerializable(OverLimitDbAdapter.KEY_ROWID);
if (mRowId == null) {
Bundle extras = getIntent().getExtras();
drinkButton = extras.getString(drinkButton);
mRowId = extras != null ? Long.parseLong(extras.getString(OverLimitDbAdapter.KEY_ROWID))
: null;
}
}
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
//saveState();
outState.putSerializable(OverLimitDbAdapter.KEY_ROWID, mRowId);
}
private Runnable returnRes = new Runnable() {
#Override
public void run() {
if(m_drinks != null && m_drinks.size() > 0){
m_adapter.notifyDataSetChanged();
for(int i=0;i<m_drinks.size();i++)
m_adapter.add(m_drinks.get(i));
}
m_ProgressDialog.dismiss();
m_adapter.notifyDataSetChanged();
}
};
#Override
protected void onListItemClick(ListView l, View v, int position, long id)
{
try
{
super.onListItemClick(l, v, position, id);
CreateDrinkOption bkg = (CreateDrinkOption)l.getItemAtPosition(position);
String drink1type = bkg.getDrinkType().toString();
float drink1units = (bkg.getPercentageByVolume() * bkg.getVolume());
//Toast.makeText(this, mRowId.toString(), Toast.LENGTH_LONG).show();
mDbHelper.updateDrink(mRowId, drink1type, drink1units);
finish();
}
catch(Exception ex)
{
Toast.makeText(this, "error", Toast.LENGTH_LONG).show();
}
}
private void getDrinks(){
try{
m_drinks = new ArrayList<CreateDrinkOption>();
CreateDrinkOption o1 = new CreateDrinkOption();
o1.setDrinkType("Beer - 1 pint");
o1.setPercentageByVolume((float) 4.5);
o1.setVolume((float) 0.5);
m_drinks.add(o1);
CreateDrinkOption o2 = new CreateDrinkOption();
o2.setDrinkType("Wine - small glass");
o2.setPercentageByVolume((float) 12);
o2.setVolume((float) 0.125);
m_drinks.add(o2);
CreateDrinkOption o3 = new CreateDrinkOption();
o3.setDrinkType("Spirit - single");
o3.setPercentageByVolume((float) 40);
o3.setVolume((float) 0.25);
m_drinks.add(o3);
CreateDrinkOption o4 = new CreateDrinkOption();
o4.setDrinkType("Alcopop - bottle");
o4.setPercentageByVolume((float) 5);
o4.setVolume((float) 0.275);
m_drinks.add(o4);
Thread.sleep(1000);
Log.i("ARRAY", ""+ m_drinks.size());
} catch (Exception e) {
Log.e("BACKGROUND_PROC", e.getMessage());
}
runOnUiThread(returnRes);
}
private class DrinkAdapter extends ArrayAdapter<CreateDrinkOption> {
private ArrayList<CreateDrinkOption> items;
public DrinkAdapter(Context context, int textViewResourceId, ArrayList<CreateDrinkOption> items) {
super(context, textViewResourceId, items);
this.items = items;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
View v = convertView;
if (v == null) {
LayoutInflater vi = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = vi.inflate(R.layout.drink_row, null);
}
CreateDrinkOption o = items.get(position);
if (o != null) {
TextView tt = (TextView) v.findViewById(R.id.drinkdetail);
TextView bt = (TextView) v.findViewById(R.id.drinkunits);
if (tt != null) {
tt.setText("Type: "+o.getDrinkType());
}
if(bt != null){
bt.setText("Units: "+ String.valueOf(o.getPercentageByVolume() * o.getVolume()));
}
}
return v;
}
}
}
Sorry for the long post, but all I need to do is make this value for mRowId available to all activites so I can read/write data at any point. The data also needs to be there if the app is paused or interupted by say an incoming call, so I use onSaveInstanceState.
ok, thanks. So reply to great answers and I have done this, but it crashes trying to get the data. I have this as my Application class:
public class OverthelimitApplication extends Application {
private Long rowId;
public Long getRowId() {
return rowId;
}
public void setRowId(Long value) {
rowId = value;
}
}
then set value with this:
OverthelimitApplication app1 = (OverthelimitApplication)getApplicationContext();
app1.setRowId((long) cursor.getColumnIndexOrThrow(OverLimitDbAdapter.KEY_ROWID));
then try to get value with this and it crashes:
mRowId = ((OverthelimitApplication) getApplicationContext()).getRowId();
I have fixed it! using this the set and get:
app1.setRowId(Long.parseLong(cursor.getString(cursor.getColumnIndexOrThrow(OverLimitDbAdapter.KEY_ROWID))));
mRowId = (long)((OverthelimitApplication)getApplicationContext()).getRowId();
I still had to specify long when setting and getting. Thanks for all your input.

Another way is to create a application class which is available for all activities.
To do that, you have to extend you Manifest with
<application
..
android:name=".MyApplication" >
and create a new Class
public class MyApplication extends Application {
public int rowId = 0;
}
inside the activities, you can access the rowId by
int mRowId = ((MyApplication) getApplicationContext()).rowId;

There are two options that I think are fit for your purpose:
SharedPreferences: the added benefit is that your variables will kept and available next time you start the application. You can store primitive types easily in shared preferences, like your rowId.
Application: you can subclass the application class, something like MyApplication extends Application, declare in your manifest that you're using this class instead of the default application, and access it using getApplication from all your activities. The added benefit is you can store anything, even a complex data structure in the application, you define the member and access methods in your MyApplication class. For example you could store the whole row of data in your application, not just the rowId)
Personally, I use SharedPreferences to remember settings that I want to be saved for the user, and not having to set them again each time the application is started is nice. And I use application for all the temporary data that I want to live across all activities as long as the application is open.

I'll describe 2 ways.
1) Use a static variable in any one of the Activities. This is the quick, dirty and lazy way. You've been warned.
2) Create your Application class.
Create a Simple class MyApplication that extends Application
In the Android Manifest, there should be a field for Application, make sure you choose your Class.
Typical example.
public class MyApp extends Application
{
private Object myGloballyAccessibleObject; //make getter and setter
private static MyApp singleInstance = null;
public static MyApp getInstance()
{
return singleInstance;
}
#Override
public void onCreate() {
super.onCreate();
singleInstance = this;
}
}
In your activities,
Call this
MyApp myApp = MyApp.getInstance();
myApp.getMyAwesomeObject(); //Booyaah!

You can use the ApplicationContext too. In your Manifest, you should have something like this :
<application
...
android:name="xx.xx.MyApp"
...>
Now, you can access to the Application from any Activity thanks to :
MyApp application = (MyApp)this.getApplicationContext();
You can put your attributes in this class, it'll be accessible anywhere in your app. MyApp must extends Application. See Manifest and
Application

Here you want to get mRowId values from all activity and it is primitive types, So
Either use Shared Preferences for store data or make your member field as a static globally, Then you can use this data in your whole application life cycle..
EDIT: Also you can use Application class as a singleton for your application and create field mRowId in this class and also make getter setter method for this field..