Develop Reference

how do i preserve item selected from spinner even after exiting app?

Here is my code below, which is getting item from spinner on click
public class SpinnerActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener {
private Spinner spinner1,spinner2,spinner3;
private static final String[] sports = {
"Hockey","Cricket","Football","Basketball","Badminton","Tennis"
};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_spinner);
spinner1 = (Spinner)findViewById(R.id.drop_down);
spinner2 = (Spinner)findViewById(R.id.drop_down2);
spinner3 = (Spinner)findViewById(R.id.drop_down3);
ArrayAdapter<String> adapter;
adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_spinner_item,sports);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner1.setAdapter(adapter);
spinner2.setAdapter(adapter);
spinner3.setAdapter(adapter);
}
#Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
String item = parent.getItemAtPosition(position).toString();
}
#Override
public void onNothingSelected(AdapterView<?> parent) {
}
}
How do I preserve the selected spinners' item even after exiting the application?

You can use SharedPreference to store the selected value position/id/string.
Simply add this line when you get String item
Editor edit = context.getSharedPreferences("Name_of_sf",Context.MODE_PRIVATE).edit();
edit.putString("selected_item", item);
edit.commit();
And can simply retrieve the value as
context.getSharedPreferences("Name_of_sf",Context.MODE_PRIVATE).getString("selected_item", "");

For more info #AnirudhSohil you could see the official documentation, it has a very detail examples, I hope that it helps you.
http://developer.android.com/training/basics/data-storage/shared-preferences.html

Android spinner and editText

my idea is to have a text field where I can input a name manually.
Additionally I do have a list of names. If there is at east 1 name in that list an icon should appear on the right of the EditText in order to open a Spinner to give a selection.
If no item is selected the EditText stays the same and if an item has been selected the EditText will have that item.
I'mworking with visibilities so far - but my problem is that the onNothingSelected seems not to get fired at all.
public class MainActivity extends ActionBarActivity {
private Spinner spinner;
private EditText text2;
private ImageButton button2;
private String spinner_value = "";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
spinner = (Spinner)findViewById(R.id.spinner);
String[] str = {"","good", "dislike", "like", "hate", "moderate"};
spinner.setPrompt("Set Text");
ArrayAdapter<String> list = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_dropdown_item, str);
spinner.setAdapter(list);
spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> arg0, View arg1,
int arg2, long arg3) {
TextView tv = (TextView)arg1;
spinner_value = tv.getText().toString();
if(spinner_value.length() == 0)
{
spinner_value = "Nothing";
}
Toast.makeText(getApplicationContext(), spinner_value, Toast.LENGTH_SHORT).show();
spinner = (Spinner) findViewById(R.id.spinner);
text2 = (EditText) findViewById(R.id.editText);
button2 = (ImageButton) findViewById(R.id.imageButton);
text2.setVisibility(View.VISIBLE);
button2.setVisibility(View.VISIBLE);
spinner.setVisibility(View.INVISIBLE);
String myStr = spinner.getSelectedItem().toString();
text2.setText(myStr);
text2.requestFocus();
}
#Override
public void onNothingSelected(AdapterView<?> arg0) {
Toast.makeText(getApplicationContext(), "NothingSelected", Toast.LENGTH_SHORT).show();
spinner = (Spinner) findViewById(R.id.spinner);
text2 = (EditText) findViewById(R.id.editText);
button2 = (ImageButton) findViewById(R.id.imageButton);
text2.setVisibility(View.VISIBLE);
button2.setVisibility(View.VISIBLE);
spinner.setVisibility(View.INVISIBLE);
text2.requestFocus();
}
});
}
}

By default, the item at index 0 is selected when you spinner is created. So, even though the user doesn't actually do anything, the first item is selected. You can see this happen by setting a breakpoint (or some other notification) in onItemSelected() and seeing it get triggered on startup without the user doing anything.
For the onNothingSelected() callback to get triggered, whatever item is selected has to disappear.

get spinner position and use it in button onclick

I am trying to make app with one text view, one button and one spinner. I make button work showing random values from string array, but i have a lot different string arrays(list1, list2 etc). Now my question is when change spinner position, how to get button get another string array(from spinner) and show it to textview.
How to pass value from spinner when something is selected in spinner to button.
Any help is appreciated.
Here is my code:
public class MainActivity extends Activity implements AdapterView.OnItemSelectedListener {
Button btn;
public String[] myString,myString1;
public static final Random rgenerator = new Random();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//textview
final TextView tv = (TextView) findViewById(R.id.textureView);
final Resources res = getResources();
//string
myString = res.getStringArray(R.array.World_War_I);
myString1 = res.getStringArray(R.array.World_War_II);
//button
btn = (Button) findViewById(R.id.buttonxx);
btn.setOnClickListener(new View.OnClickListener(){
public void onClick (View v){
//i am missing code here, spinner position, and pass spinner position to if statement.
if (==0){
myString = res.getStringArray(R.array.list1);
String q = myString[rgenerator.nextInt(myString.length)];
tv.setText(q);
}
if (==1){
myString1 = res.getStringArray(R.array.list2);
String q1 = myString1[rgenerator.nextInt(myString.length)];
tv.setText(q1);
}
}
});
//drop list
Spinner spinner = (Spinner) findViewById(R.id.spinnerrrr);
spinner.setOnItemSelectedListener(this);
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,
R.array.kategorije, android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
}
// when some cat selected
public void onItemSelected(AdapterView<?> parent, View view,
final int pos, long id) {
// An item was selected. You can retrieve the selected item using
parent.getItemAtPosition(pos);
parent.setSelection(0);
parent.getSelectedItemPosition();
}
public void onNothingSelected(AdapterView<?> parent) {
// Another interface callback
}

Use this
// when some cat selected
public void onItemSelected(AdapterView<?> parent, View view,
final int pos, long id) {
// An item was selected. You can retrieve the selected item using
btn.setTag(pos+""); // Passing as string
parent.getItemAtPosition(pos);
parent.setSelection(0);
parent.getSelectedItemPosition();
}
and then
btn.setOnClickListener(new View.OnClickListener(){
public void onClick (View v){
//i am missing code here, spinner position, and pass spinner position to if statement.
int index = Integer.parseInt(btn.getTag().toString());
if (index==0){
myString = res.getStringArray(R.array.list1);
String q = myString[rgenerator.nextInt(myString.length)];
tv.setText(q);
}
if (index==1){
myString1 = res.getStringArray(R.array.list2);
String q1 = myString1[rgenerator.nextInt(myString.length)];
tv.setText(q1);
}
}
});

Android: Changing a textview with in a different Activity

I am trying to change textview properties of a textview that looks like this:
In a seperate Activity that looks like this:
I tried to do this with bundles but I can't get it to work.
This is how my BookActivity looks like:
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.book_activity);
//this is where the size property comes in
Integer size = getIntent().getExtras().getInt("SGRkey");
TextView test2 = (TextView) findViewById(R.id.booktext);
test2.setTextSize(size);
Spinner spinner = (Spinner) findViewById(R.id.kapitelspinner);
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
this, R.array.kapitel_array, android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
spinner.setOnItemSelectedListener(new MyOnItemSelectedListener());
}
public class MyOnItemSelectedListener implements OnItemSelectedListener {
public void onItemSelected(AdapterView<?> parent,
View view, int pos, long id) {
Toast.makeText(parent.getContext(),
parent.getItemAtPosition(pos).toString(), Toast.LENGTH_LONG).show();
final String[] theporn = getResources().getStringArray(R.array.allkapitel);
TextView text = (TextView) findViewById(R.id.booktext);
text.setText(theporn[pos]);
}
public void onNothingSelected(AdapterView parent) {
// Do nothing.
}
(i pick the chapter string in the spinner and that works just fine.)
And this is how my SettingsActivity looks like:
public class SettingsActivity extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.settings_view);
Spinner SGRspinner = (Spinner) findViewById(R.id.schriftgroeße_spinner);
ArrayAdapter<CharSequence> SGRadapter = ArrayAdapter.createFromResource(
this, R.array.schriftgroesse_list, android.R.layout.simple_spinner_item);
SGRadapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
SGRspinner.setAdapter(SGRadapter);
}
public class SGROnItemSelectedListener implements OnItemSelectedListener {
public void onItemSelected(AdapterView<?> parent,
View view, int pos, long id) {
Intent answer = new Intent();
Toast.makeText(parent.getContext(),
parent.getItemAtPosition(pos).toString(), Toast.LENGTH_LONG).show();
final String[] SGRstring = getResources().getStringArray(R.array.schriftgroesse_list);
int SGRint = Integer.parseInt(SGRstring[pos]);
Bundle size = new Bundle();
size.putInt("SGRkey", SGRint);
Intent nextActivity = new Intent(com.asm.reader.SettingsActivity.this, com.asm.reader.BookActivity.class);
nextActivity.putExtras(size);
com.asm.reader.SettingsActivity.this.startActivity(nextActivity);
}
public void onNothingSelected(AdapterView parent) {
// Do nothing.
}
}
I get an error when I try this. All activities are declared in the manifest. I really don't know how to go on. I'm pretty new to this, so sorry if this is something simple, but any help would be greatly appreciated!! :-)

Make your textview static. That is, declare it as a public static class variable. Then you can call it directly from the other activity like this: firstActivity.myTextView.setText("foo");

Android onItemSelected - NullPointer

following code is throwing a NullPointerException:
public class test extends Activity implements OnItemSelectedListener {
private TextView explanation;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.psqlpicker);
explanation = (TextView) findViewById(R.id.picker_explanation_text);
Spinner spinner = (Spinner) findViewById(R.id.spinner);
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
this, R.array.picker_array,
android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setOnItemSelectedListener(new test());
spinner.setAdapter(adapter);
}
#Override
public void onItemSelected(AdapterView<?> parent, View view, int pos,
long id) {
explanation = (TextView) findViewById(R.id.picker_explanation_text);
}
}
It is thrown because of explanation = (TextView) findViewById(R.id.picker_explanation_text); in the onItemSelected(...) method, but I have no idea why. It is, after all, working in the onCreate(...) method.

Instead of
spinner.setOnItemSelectedListener(new test());
use
spinner.setOnItemSelectedListener(this);
You want to use your real activity as the target; you are creating a new object that is never initialized with a context so when it is called it crashes.