I have two simple Activities -
Activity1: ListView from an Array
Activity2: EditText for editing the clicked row in Activity1
When I edit the value in Activity2 and returning to Activity1, the ListView doesn't reload the new value.
I want to refresh the ListView when I return from Activity2 or resume Activity1 or something that will update the list.
My code:
static ArrayAdapter<String> dataAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Loading the values to list array
String[][] fulllist = loadArrays();
String[] list = new String[fulllist.length];
for(int i = 0; i<fulllist.length; i++) {
list[i] = fulllist[i][1];
}
// --------------------------------
dataAdapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1,
list);
setListAdapter(dataAdapter);
}
#Override
public void onResume() {
super.onResume();
// Loading the values to list array
String[][] fulllist = loadArrays();
String[] list = new String[fulllist.length];
for(int i = 0; i<fulllist.length; i++) {
list[i] = fulllist[i][1];
}
// --------------------------------
dataAdapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1,
list);
dataAdapter.notifyDataSetChanged();
}
loadArrays() is just method that converts from SharedPreferences to String Array. Activity2 saves the new data in SharedPreferences and than Activity1 can read it (with the new data).
If I return to the "main activity" (it is not Activity1) and than come back to Activity1 - the new data is shown, but I want this data will be updated when I return from Activity2 immediately.
loadArrays() method: pastebin.com/MHwNC0jK
Thanking you in advance!
On clicking the item in your first Activity, start your second Activity with startActivityForResult()
And then in Second Activity, after entering in EditText, probably there is a button. And in onClick of that button call,
intent.putExtra("edittextvalue", findViewById(R.id.edittext).getText().toString());
setResult(RESULT_OK, intent);
finish();
Now you come back to your first Activity and here you have to implement onActivityResult() callback. You can extract data from that intent's extras and set that respective item in your array and call notifyDataSetChanged().
This is ideally how you should be doing it.
If you want more info on how to use startActivityForResult() try this link - http://manisivapuram.blogspot.in/2011/06/how-to-use-startactivityforresult.html
1) Get reference ListView
mListView = (ListView)findViewById(R.id.auto_listview);
2) Create adapter One more time with changed values
MyAdapter myAdapter = new MyAdapter(getApplicationContext(),
R.layout.locations_list_item_layout,dataArray;
mListView.setAdapter(myAdapter);
setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> adapterView,
View view, int i, long l) {
myAdapter = new MyAdapter(getApplicationContext(),
//pass changed values vlues array R.layout.locations_list_item_layout,dataArray;
mListView.setAdapter(myAdapter);
}
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
}
});
Declare fulllist as Globle Variable and used static arraylist .
Related
I want to pass values to list view by clicking a button. Problem is I want to make a list by gaining values from different activities with several buttons.
For Example :
In EnglandActivity if I click Button Visit I want to pass "England" to ListView in MainActivity,
In MalaysiaActivity pass "Malaysia" to ListView in MainActivity.
I dont know how to do that, Can you help me??
First Of All, You should write this on your onCreate() method of MainActivity.java
#Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String data;/*For Storing Country Name*/
ListView listview = (ListView)findViewById(R.id.listView); /*Finding ListView From Layout*/
ArrayList<String> list = new ArrayList<String>(); /*ArrayList To Store All The Data Of ListView*/
ArrayAdapter adapter= new ArrayAdapter<String>(this,R.layout.android.R.layout.simple_list_item_1,list);/*Defining ArrayAdapter For ListView*/
listview.setAdapter(adapter); /*Setting Adapter To ListView*/
Bundle intentExtras = getIntent().getExtras(); /*Getting The Intent Extras Sent By The Activity Which You Had Navigated From*/
if(intentExtras != null) {/*Checking For Null*/
data= intentExtras.getString("countryName");/*Extracting The Data From The Intent Extras*/
list.add(0,data);/*You Can Replace 0 With The Position Of Your Wish*/
} else {
data=null;
}
}
Now Write This In The OnClickListener() Method Of Button On Each CountryNameActivity.java
btn.setOnClickListener(new OnClickListener() {/*Setting The Click Listener*/
#Override
public void onClick(View v) {
Intent intent = new Intent(this,MainActivity.this)/*Defining The Intent*/
intent.putExtra("countryName","CountryName");/*Putting The Data To Pass To The Next Activity*/
startActivity(intent);/*Starting The Activity*/
}
});
Make an object shared by all of your activity, put your data there and read them when you must put data into your ListView's adapter
myListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int
position, long id) {
Intent listIntent = new Intent(getApplicationContext(), YourActivity.class);
listIntent.putExtra("country", yourList.get(position));
startActivity(listIntent);
}
});
in next activity onCreate:
String country;
Bundle extras = getIntent().getExtras();
if(extras == null) {
country= null;
} else {
country= extras.getString("country");
}
this is my very first question so go easy on me :)
I am new to android, and I am trying to make a simple list. On the first Activity the user can enter data, which should display as a list on the second Activity.
I am using Intents to pass the data from one Activity to another, but I know I am missing something crucial in my ClassB Activity as nothing displays.
Here is my main code:
public class ClassA extends AppCompatActivity {
EditText note;
Button saveNoteB, goToNotesB;
public final static String EXTRA_NOTE = "com.lisa.currys.userlistarray.note";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
saveNoteB = (Button) findViewById(R.id.saveNote);
saveNoteB.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent i = new Intent(ClassA.this, ClassB.class);
note = (EditText) findViewById(R.id.note);
String userInput = note.getText().toString();
ArrayList<String> arr = new ArrayList<String>();
arr.add(userInput);
i.putStringArrayListExtra("note", arr);
startActivity(i);
}
});
and for my second activity:
public class ClassB extends AppCompatActivity {
public static android.widget.ListView displayNotes;
ArrayList<String> arr = new ArrayList<String>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
arr = getIntent().getExtras().getStringArrayList(ClassA.EXTRA_NOTE);
displayNotes = (ListView)findViewById(R.id.listView);
Intent i = getIntent();
arr = i.getStringArrayListExtra("note");
ArrayAdapter<String> adapter = new ArrayAdapter<String>(ClassB.this, android.R.layout.simple_list_item_1);
displayNotes.setAdapter(adapter);
}
}
Any pointers or advice would be most welcome.
Thank you.
You are never actually adding the elements in arr to the ArrayAdapter. Use the three argument constructor for ArrayAdapter like below which will add the elements:
ArrayAdapter<String> adapter =
new ArrayAdapter<String>(ClassB.this, android.R.layout.simple_list_item_1, arr);
In ClassA try this:
i.putStringArrayListExtra(EXTRA_NOTE, arr);
or in ClassB try this:
arr = getIntent().getExtras().getStringArrayList("note");
You have to use the same key to set and get the values.
By the way, why are you assign values to "arr" two times?
Try this
ArrayAdapter<String> adapter = new ArrayAdapter<String>(ClassB.this, android.R.layout.simple_list_item_1);
Above statement you are pass the context and layout in which your data
display but you are not give the data which is store
in your **arr** arraylist so you not show anything.
replace this statement to
ArrayAdapter<String> adapter =
new ArrayAdapter<String>(ClassB.this, android.R.layout.simple_list_item_1, arr);
How can i get user inputs from one activity and populate the listView with user data in another activity. I am able to get user input and populate the listView in the same activity. but now i want to get user inputs in one form and populate the list in another activity.
the code that i used to populate the listView by getting user input is as follows
public class MainActivity extends ListActivity {
ArrayList<String> list = new ArrayList<String>();
/** Declaring an ArrayAdapter to set items to ListView */
ArrayAdapter<String> adapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button btn = (Button) findViewById(R.id.btnAdd);
/** Defining the ArrayAdapter to set items to ListView */
adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, list);
/** Defining a click event listener for the button "Add" */
View.OnClickListener listener = new View.OnClickListener() {
#Override
public void onClick(View v) {
EditText edit = (EditText) findViewById(R.id.txtItem);
String name=edit.getText().toString();
list.add(name);
edit.setText("");
adapter.notifyDataSetChanged();
}
};
/** Setting the event listener for the add button */
btn.setOnClickListener(listener);
you can store your user input / data into a local database; that will allow you to access your data anywhere in the app
(recommended since you are dealing with listview).
you can use shared preferences to store data if your data is relatively small.
In your current Activity (activity contains your button), create a new Intent:
String name = "";
name = edit.getText().toString();
Intent i = new Intent(getApplicationContext(), NewActivity.class);
i.putExtra("keyword",name);
startActivity(i);
Then in the NewActivity (activity contains your Listview), retrieve those values:
Bundle extras = getIntent().getExtras();
if (extras != null) {
String name = extras.getString("keyword");
if(name != ""){
// adapter.notifyDataSetChanged();
}
}
It is simple way, hope this help
Declare a public method in second Activity like
SecondActivity.class
public static ArrayList<String> list = new ArrayList<String>();
/** Declaring an ArrayAdapter to set items to ListView */
ArrayAdapter<String> adapter
onCreate()
{
...
;
adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, list);
listview.setAdapter(adapter);
...
}
public static void ModifyList()
{
adapter.notifyDataSetChanged();
}
FirstActivity.class
View.OnClickListener listener = new View.OnClickListener() {
#Override
public void onClick(View v) {
EditText edit = (EditText) findViewById(R.id.txtItem);
String name=edit.getText().toString();
SecondActivity.list.add(name);
edit.setText("");
SecondActivity.ModifyList();
}
};
Send your ArrayList like this from FirstActivity :
Intent intent = new Intent(FirstActivity.this, SecondActivity.class);
intent.putStringArrayListExtra("Datalist",list);
startActivity(intent);
In secondActivity Recieve the list using :
Intent i = getIntent();
list = i.getStringArrayListExtra("Datalist");
Then display it in your SecondActivitys listview
Hey guys I'm working on an app in android studio. I have a listview and when I make a selection i would like to add that selection to another listview in a different activity. What is the easiest/best way to do this? I've tried putExtra without any luck. Any examples or ideas would be great. Thank you guys.
Thanks for the examples everyone they've helped me understand a lot better the intent system. I've been trying the different examples everyone has posted and I've kind of gotten stuck. The goal is simply to have the items I select from the listview in the Walmart.java file to show up in the listview in GiftsSelected.java I have another place to open the activity so I don't need it to immediately open the new activity.
Here is my code:
This is Walmart.java
public class Walmart extends ActionBarActivity {
private String[]giftarray = {
"Apple" ,
"Bananas",
"Bed",
"Beef",
"Bottle",
"Bread",
"Broccoli",
"Carrots",
"Cat",
"Chicken",
"Chocolate",
"Computer",
"Cow",
"Crow",
"Dog",
"Dolphin",
"Dove",
"Drawer",
"Egg",
"Fish",
"Fork",
"Fridge",
"Giraffe",
};
Intent a = new Intent(Walmart.this,GiftsSelected.class);
private ListView giftListView;
private ArrayAdapter arrayAdapter;
ArrayList<String> list = new ArrayList<String>();
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo){}
public boolean onContextItemSelected(MenuItem item){
return true;
}
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_walmart);
getSupportActionBar().hide();
giftListView = (ListView) findViewById(R.id.gift_list1);
arrayAdapter = new ArrayAdapter(this, android.R.layout.simple_gallery_item, giftarray );
giftListView.setAdapter(arrayAdapter);
giftListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
String item = "Item added to registry";
list.add(item2);
a.putStringArrayListExtra("list",list);
Toast.makeText(getBaseContext(), item, Toast.LENGTH_LONG).show();
}
});
}
This is my GiftsSelected.java code:
public class GiftsSelected extends ActionBarActivity {
private ListView giftListView;
private ArrayAdapter arrayAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
ArrayList<String> list = new ArrayList<String>();
//This makes my app crash which makes me think I did this wrong...
list = getIntent().getStringArrayListExtra("list");
String[] giftarray = new String[list.size()];
list.toArray(giftarray);
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_gifts_selected);
getSupportActionBar().hide();
giftListView = (ListView) findViewById(R.id.gift_list1);
arrayAdapter = new ArrayAdapter(this, android.R.layout.simple_gallery_item, giftarray);
giftListView.setAdapter(arrayAdapter);
giftListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
String item = "Item added to your registry";
Toast.makeText(getBaseContext(), item, Toast.LENGTH_LONG).show();
}
});
}
this is the list that i use
ArrayList<String> list = new ArrayList<String>();
add elements in it like this
list.add("something");
in first Activity
Intent i=new Intent(FirstActivity.this,SecondActivity.class);
i.putStringArrayListExtra("list",list);
startActivity(i);
in the second activity in the onCreate
list = getIntent().getStringArrayListExtra("list");
Let's say the first Activity is X and X holds a listview that updates another listview in Activity Y.
If X is tightly related to Y, that is to say Y launches X, gets data then immediately returns to Y, then you should use startActivityForResult from Y.
class ActivityY {
public static final int REQUEST_CODE = 2;
...
Intent i = new Intent(this, ActivityX.class);
startActivityForResult(i, REQUEST_CODE);
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == REQUEST_CODE) {
if (resultCode == RESULT_OK) {
String returndata = data.getStringExtra("rowdata");
//update your listView, do notifyDataSetChanged() etc;
}
}
}
}
class ActivityX {
// in listview onItemClickListener or elsewhere that listens to row click
Intent intent = new Intent();
returnIntent.putExtra("rowdata", rowdata); // whatever data you need to transfer
setResult(RESULT_OK,intent);
finish();
}
If X and Y are loosely related, that is to say X is not necessarily launched from Y, but goes to Y then you should just use the usual startActivity(intent).
if X and Y are completely independent, that is to say X is not necessarily launched from Y, may not go to Y or wanders other Activities before arriving in Y then you should cache the data. If the data size is small then the best way is to store it in Preferences. When you Y Activity starts, get the data, update your ListView, then if needed remove the cached data from Preferences.
a)You can make the listview item object parcelable and send it between activities via intent extra.
b)You can save the selected listview item in a global variable.(Not recommended)
So I have my main activity which holds a list view and has a map which holds all my data for the list. Upon clicking on an item you are taken to a details display. When I press the back button to get back to the main activity from the detail activity, if I set a break point, my map keys are still intact, but all the strings in the objects are "" and the ints are -1. Here is what my main activity looks like:
public class MainActivity extends Activity {
private Map<String, Stunt> stunts = new LinkedHashMap<String, Stunt>();
private StuntsDao stuntsDao;
private ListAdapter listAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
stuntsDao = new StuntsDao(getApplicationContext());
stunts = stuntsDao.getAllStunts();
listAdapter = new ListAdapter(this, R.layout.list_layout, new ArrayList<Stunt>(stunts.values()));
ListView listView = (ListView)findViewById(R.id.listView);
listView.setAdapter(listAdapter);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
String stuntName = (String)((ViewHolder)view.getTag()).stuntName.getText();
Intent myIntent = new Intent(getApplicationContext(), StuntDetails.class);
getStuntDetailsIfNeeded(stuntName);
Stunt stunt = stunts.get(stuntName);
myIntent.putExtra("STUNT", stunt);
startActivity(myIntent);
}
});
}
...
}
Why would the objects in my map be basically empty?
onCreate() doesn't get called when you click back. You need to init your data again in onStart or onResume. See: http://developer.android.com/training/basics/activity-lifecycle/starting.html