scenario:
First mainactivity launches and from the menu option user launches second activity using intent and there he adds some text to edittext and get that edittext value using intent to the first activity and add that value to the listview.
FirstActivity:
public class MainActivity extends Activity {
ListView lv;
EditText et;
String AddedTask ;
ArrayList<Model> modelList;
CustomAdapter adapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Intent intent = getIntent();
if (intent.hasExtra("NewTask")) {
AddedTask = this.getIntent().getExtras().getString("NewTask");
lv = (ListView) findViewById(R.id.listViewData);
String name = AddedTask;
Model md = new Model(name);
modelList.add(md);
adapter = new CustomAdapter(getApplicationContext(), modelList);
lv.setAdapter(adapter);
adapter.notifyDataSetChanged();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar actions click
switch (item.getItemId()) {
case R.id.action_settings:
return true;
case R.id.action_add_task:
Intent i = new Intent(MainActivity.this, AddTask.class);
startActivity(i);
return true;
default:
return super.onOptionsItemSelected(item);
}
}
}
Second Activity:
public class AddTask extends Activity {
Button addtask;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.add_task);
// get action bar
ActionBar actionBar = getActionBar();
// Enabling Up / Back navigation
actionBar.setDisplayHomeAsUpEnabled(true);
addtask = (Button) findViewById(R.id.btnaddlist);
findViewById(R.id.btnaddlist).setOnClickListener(
new View.OnClickListener() {
public void onClick(View arg0) {
EditText edit = (EditText) findViewById(R.id.tskname);
Intent i = new Intent(AddTask.this,
MainActivity.class);
//Bundle bundle = new Bundle();
String TaskName = edit.getText().toString();
//bundle.putString("NewTask", TaskName);
i.putExtra("NewTask", TaskName);
i.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
//i.putExtras(bundle);
startActivity(i);
}
});
}
}
Now my problem is I'm able to add the data to the listview but each time I come back to mainactivity the previous data which was added is lost and updating the old data with my new data.
I have searched for many SO answers and most of them suggest to add adapter.notifyDataSetChanged(); which I have already tried and nothing worked.
I have done by checking the adapter is null or updating the data this way and getting null pointer exception:
if ( adapter== null )
{
adapter = new CustomAdapter(getApplicationContext(), modelList);
lv.setAdapter(adapter);
}
Can anyone say me how do I get this working ?
new View.OnClickListener() {
public void onClick(View arg0) {
EditText edit = (EditText) findViewById(R.id.tskname);
Intent i = new Intent(AddTask.this,
MainActivity.class);
//Bundle bundle = new Bundle();
String TaskName = edit.getText().toString();
//bundle.putString("NewTask", TaskName);
i.putExtra("NewTask", TaskName);
i.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
//i.putExtras(bundle);
startActivity(i);
}
});
You are starting a new Activity each time you want to add an item.
Consider using
startActivityForResult()
Link to Android Documentation
Even if startActivityForResult() is IMHO the best way to fix your problem, i'll give you a hint why it doesn't show your "old" data.
You don't finish your first Activity when going to the Second. You could aswell just finish your second activity and your MainActivity would run into
onResume()
therefor check the Android lifecycle
Don't use putextra and intent techniques. Follow below technique.
In main activity create sharedpref as follows:
public static final String SharedPref = "MyPreferences";
In activity 2 insert this code.
SharedPreferences settings=null;//declaration
settings=getSharedPreferences(SharedPref,0);//initialization
String TaskName= edit.getText().toString();
SharedPreferences.Editor editor = settings.edit();
editor.putString("NewTask", TaskName);
editor.commit();
finishfromchild(AddTask.this);
In main activity:
SharedPreferences settings=null;//declaration
In onCreate
//now initialise settings
settings=getSharedPreferences(SharedPref,0);//SharedPref is the foldername
//of your sharedpreferences(you create it first)
//Now create onResume method
public void onResume()
{
super.onResume();
AddedTask=settings.getString("NewTask", "");
lv = (ListView) findViewById(R.id.listViewData);
String name = AddedTask;
Model md = new Model(name);
modelList.add(md);
adapter = new CustomAdapter(getApplicationContext(), modelList);
lv.setAdapter(adapter);
}
Hope this works. I did the same in my previous project.
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");
}
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
I have two activities, in the main one I have a text field and two buttons, the user can enter text in the text field.
When clicking the add button,text will be added to some ArrayList.
When clicking show in list button a new activity with its own fragment should open showing a listview that contains the names that the user has entered.
I used ArrayAdapter and this is working fine. When I am in the list activity and when I click the back button of the device everything goes fine and the data in the ArrayList is not lost.
If I click show in list again I will find the old data I entered at the first time. But, if I click the back icon provided by Android at the top left of the device screen, the ArrayListbecomes empty and when I click show in list the listview shows as empty.
Here is the main activity code,
public class MainActivity extends ActionBarActivity {
String LOG_TAG = this.getClass().getSimpleName();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final ArrayList<String> itemList= new ArrayList<String>();
final EditText text = (EditText) findViewById(R.id.text_field);
text.setHint("Enter name here");
Button addButton = (Button) findViewById(R.id.add_button);
Button showButton = (Button) findViewById(R.id.show_button);
addButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String name= text.getText().toString();
itemList.add(name);
if (itemList.size()==1){
Toast.makeText(getApplicationContext(), "one", Toast.LENGTH_SHORT).show();
}
Toast.makeText(getApplicationContext(), "name has been added to the list", Toast.LENGTH_SHORT).show();
}
});
showButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent intent = new Intent (getApplicationContext(), ListActivity.class);
intent.putExtra("list", itemList);
startActivity(intent);
}
});
}//end oncreate
This is the ListActivity and its fragment code,
public class ListActivity extends ActionBarActivity {
static ArrayList <String> itemList;
String LOG_TAG = this.getClass().getSimpleName();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
itemList= getIntent().getStringArrayListExtra("list");
setContentView(R.layout.list_activity);
if (savedInstanceState==null){
getSupportFragmentManager().beginTransaction().add(R.id.container, new list()).commit();
}
}
public static class list extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container,false);
ListView listView = (ListView) rootView.findViewById(R.id.list);
ArrayAdapter <String> adapter= new ArrayAdapter<String>(getActivity(),R.layout.fragment_main, R.id.row, itemList);
listView.setAdapter(adapter);
return rootView;
}
}
}
Can anyone please tell me why this is happening? How can I solve this issue?
Any help is appreciated.
Many thanks.
create a class Constantss.java and declare
public static ArrayList <String> itemList=null;
then inside your class
use
Constantss. itemList.add(name);
instead of
itemList.add(name);
// replace itemList with Constantss. itemList in all of your classes
I believe this is a navigation issue. So you should close your ListActivity like this:
public class ListActivity extends ActionBarActivity {
//your code
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int itemID = item.getItemId();
switch (itemID ) {
case android.R.id.home:
this.finish();
return true;
}
return super.onOptionsItemSelected(item);
}
}
Anyway your data can be lost if android destroys your MainActivity. So if you navigate from ListActivity back to MainActivity, MainActivity will be recreated and you data get lost. So you should find the way how to save your
data permanent.
there are two common ways:
Save data to data base (SQLite)
Save data to Preferences How to store list of values in SharedPreferences
I have two class Profile.class and Details.class,
In profile class i have used a spinner with values like (ATM,Banking,Personal,Others etc)
and a button (OK).
on clicking ok button it will go to next activity that is details activity where i will be taking some details like-name,description etc.
after filling the details i have given a button (save).
on clicking button save i will be saving the name and description in database but i want to save the profile name also along with details. i am unable to transfer selected spinner text from Profile.class to Details.class
how to transfer?
create.class code
public class Create extends Activity {
public ArrayList<String> array_spinner;
Button button4;
String spinnertext;
/** Called when the activity is first created. */
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.create);
Spinner spinner = (Spinner) findViewById(R.id.spinner1);
array_spinner=new ArrayList<String>();
array_spinner.add("ATM");
array_spinner.add("Bank");
array_spinner.add("Mail");
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item, array_spinner);
adapter.setNotifyOnChange(true);
spinner.setAdapter(adapter);
spinner.setLongClickable(true);
spinner.setOnLongClickListener(new OnLongClickListener(){
public boolean onLongClick(View v) {
// TODO Auto-generated method stub
return false;
}}
);
button4 = (Button)findViewById(R.id.button4);
button4.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Intent myIntent4 = new Intent(view.getContext(), Details.class);
startActivityForResult(myIntent4, 0);
myIntent4 .putExtra("key", array_spinner.getSelectedItem().toString());
startActivity(myIntent4);
}
});
}}
details.class code
public class Details extends Activity {
EditText editText4,editText5,editText6;
Button button8,button9,button10;
TextView textView7;
String et4,et5,et6;
//SQLite Database db;
/** Called when the activity is first created. */
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.details);
String spinnervalue = getIntent().getExtras().getString("Key");
please kindly explain me what is this "key"?
You can use :
Intent i = new Intent(MainActivity.this,SecondActivity.class);
i.putExtra("YourValueKey", yourData.getText().toString());
then you can get it from your second activity by :
Intent intent = getIntent();
String YourtransferredData = intent.getExtras().getString("YourValueKey");
example
this is what you have to write in your first activity
Intent i = new Intent(getApplicationContext(), Product.class);
i.putExtra("productname", ori);
i.putExtra("productcost", position);
i.startActivityForResult(i,0);
then in your next activity you need to have this code
String productname,productcost;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.product);
tv1= (TextView)findViewById(R.id.tv1);
tv2= (TextView)findViewById(R.id.tv2);
Bundle extras= getIntent().getExtras();
if(extras!=null)
{
position = extras.getString("position"); // get the value based on the key
tv1.setText(productname);//use where ever you want
productname = extras.getString("productname"); // get the value based on the key
tv2.setText(productname);
}
First of all take a spinner and provide value to them what you want and then the selected spinner value change it to string value and this string variable will be used in OK button to pass value through use of Intent or Shared preference to take this value to another activity and through there you can use it in database to display this value.
If you want to send data to another activity, you can do it using intent.
Bundle bund = new Bundle();
bund.putString("myKey",name);
Intent intent = new Intent(Profile.this, Detail.class);
intent.putExtras(bund);
startActivity(intent);
Now in Detail class, receive this data in onCreate()
#Override
protected void onCreate(Bundle savedInstanceState) {
.......
String nameReceived = getIntent().getExtras().getString("myKey");
}
I have given the example of passing String to another activity however, you can pass boolean, int, double etc to another activity. See the full list on here
i have two activity files in my code, and the first activity file loads the layout search, and the second file loads layout list. I have a textbox in layout search and enter some text. I want to use this text in my second activity file but i can not reach it since it is in the layout search. How can i do this? Here the first activity file, here there is an EditText item called searchedText, and i want to use it in the second activity file.
public class SearchActivity extends Activity{
public EditText searchedText;
public RadioGroup radioGroup;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.search);
}
public void onStart(){
super.onStart();
searchedText = (EditText) findViewById(R.id.searchText);
Button searchinSearchButton = (Button)findViewById(R.id.searchInSearch);
radioGroup = (RadioGroup) findViewById(R.id.radioGroup1);
searchinSearchButton.setOnClickListener(new View.OnClickListener(){
public void onClick(View v){
String searched=searchedText.getText().toString();
Intent myIntent = new Intent(v.getContext(),
SearchListActivity.class);
startActivityForResult(myIntent, 1);
}
});
}
}
And here is the second activity file:
public class SearchListActivity extends Activity{
public DatabaseAdapter db;
public ArrayList<String> myList;
public ListView listview;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.list);
db = new DatabaseAdapter(this);
myList = new ArrayList<String>();
getContacts();
// Example of retrieving tweets of the user "mashable" and adding them to
myList
/*
ArrayList<Tweet> tweets= new ArrayList<Tweet>();
tweets.addAll(Twitter.getTimeline("mashable", 10));
for(Tweet t: tweets){
myList.add(t.username + ": " + t.message + " Tweet id: "+ t.id);
}
*/
printList();
}
public void printList(){
listview = (ListView)findViewById(R.id.contactcListView);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, android.R.id.text1, myList);
listview.setAdapter(adapter);
}
public void getContacts() {
db.open();
Cursor c = db.getContactbyName("y");
if (c.moveToFirst()) {
do {
DisplayContact(c);
} while (c.moveToNext());
}
db.close();
}
public void DisplayContact(Cursor c) {
String entry = "";
// if you add another attribute to your table, you need to change 3 into x
for (int i=1; i<5;i++){
entry += c.getString(i) + "\n";
}
myList.add(entry);
}
}
In this second activity file, you can see the getContacts() method. There, i search by Cursor c = db.getContactbyName("y"); but instead of "y", i want to search whatever user enters the texbox, whic is in the 1st activity file called searchedText. How can i do this?
Thanks
Send the text as an extra in your Intent when you start your second activity.
searchinSearchButton.setOnClickListener(new View.OnClickListener(){
public void onClick(View v){
String searched=searchedText.getText().toString();
Intent myIntent = new Intent(v.getContext(),
SearchListActivity.class);
myIntent.putExtra("SEARCH_STRING",searched);
startActivityForResult(myIntent, 1);
}
});
And in your onCreate get the extra. You could use Intent.getStringExtra(String name)
In other words:
mySearched = getIntent().getStringExtra("SEARCH_STRING");
Just make sure to see if anything is null before using it.