Develop Reference

Spinner wont show selected and wont respond to item selection

I'm trying to make a very very simple spinner at least, as follows:
XML:
<Spinner
android:id="#+id/spinner_categories"
android:layout_width="0sp"
android:layout_height="wrap_content"
android:drawSelectorOnTop="true"
android:layout_weight="1"
android:textColor="#000000"
android:spinnerMode="dropdown"/>
JAVA:
spinnerCategories = findViewById(R.id.spinner_categories);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(
getApplicationContext(),
android.R.layout.simple_spinner_item,
categories);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinnerCategories.setAdapter(adapter);
Log.d(Utilities.LOG_FLAG, "SPINNER: " + spinnerCategories.toString());
spinnerCategories.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> adapterView, View view, int position, long l) {
Toast.makeText(context, categories.get(position).toString(), Toast.LENGTH_SHORT).show();
Log.d(Utilities.LOG_FLAG, "SELECTED");
}
#Override
public void onNothingSelected(AdapterView<?> adapterView) {
Log.d(Utilities.LOG_FLAG, " NOT SELECTED");
}
});
I can see the entire list, but once I click on an item, nothing happans, and it wont show the selection at all, even if I use setSelection(), and if I try to do spinnerCategories.getSelectedItem().toString() I get a NullPointerException.
I tried searching the web a lot, but none solution seems to help me...
Edit
For some reason when I load the page and then I go out of the page and reenter it, only then it will show the selected items of the spinner
On the first load it shows for a very brief second and then it's gone until the page is reentered the second time

The setOnItemSelectedListener gets triggered when you click on an element from the drop down menu .. to fetch the selected item you need to use .getSelectedItemPosition() something like
categoriesList.get(spinner.getSelectedItemPosition)

Android - Spinner setting TextView visible/invisible

I'm trying to do my first Spinner, and I have encountered some difficulties, such as that I don't know if I can get an option by spinner.getSelectItem == "some string".
Take a look at my code so far
Populating the spinner:
public void addItemsOnSpinner() {
Spinner buttonSpinner = (Spinner) findViewById(R.id.buttonSpinner);
List<String> list = new ArrayList<String>();
list.add("Ultimos 5 lancamentos");
list.add("Ultimos 7 lancamentos");
list.add("Ultimos 10 lancamentos");
ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this,
android.R.layout.simple_spinner_item, list);
dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
buttonSpinner.setAdapter(dataAdapter);
}
Trying to make an if statement:
if(buttonSpinner.getSelectedItem().toString() == "Ultimos 10 lancamentos"){
textView.setVisibility(View.VISIBLE);
}
TextView code as requested:
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceMedium"
android:text="Deposito"
android:visibility="invisible"
android:id="#+id/textView"
android:layout_row="2"
android:layout_column="0"
android:layout_gravity="center|left" />
And its code on the class:
TextView textView = (TextView)findViewById(R.id.textView);

Yes you can do it and it will work fine, but please use
buttonSpinner.getSelectedItem().toString().equals("Ultimos 10 lancamentos");

As Stefano has pointed out, your comparison should be using equals (which compares the String contents, vs == which compares the object references).
Otherwise your if statement should work, however its not clear where you are calling it from (and that might be the cause of the problem). If you want to make the comparison immediately after a spinner item is selected then you need to set an OnItemSelectedListener and make the comparison there.
Here is an example of how you might declare this listener inline:
buttonSpinner.setOnItemSelectedListener(new Spinner.OnItemSelectedListener()
{
public void onItemSelected(AdapterView<?> parent, View view, int position, long id)
{
String selectedItem = parent.getSelectedItem().toString();
if (selectedItem.equals("Ultimos 10 lancamentos"))
{
textView.setVisibility(View.VISIBLE);
}
}
public void onNothingSelected(AdapterView<?> parent)
{
}
});

android java set fix default value for spinner

I would like to have a fix value that is always displayed in the Spinner and when clicking on the Spinner this value should not be listed in the drop down selection.
Until now I have the following
Definition XML:
<Spinner
android:layout_width="76dp"
android:layout_height="40dp"
android:id="#+id/right_shift"
android:layout_row="0"
android:layout_column="0"/>
Java:
final Spinner right = (Spinner) findViewById(R.id.right_shift)
ArrayList<String> rightShift = new ArrayList<String>();
rightShift.add(" >>"); //THIS SHOULD BE THE VALUE THAT IS ALWAYS DISPLAYED
for (int i=0; i<5; i++)
...//add other values to arraylist
...//set values of arraylist to spinner
right.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
right.setSelection(0);
}
#Override
public void onNothingSelected(AdapterView<?> adapterView) {
}
});
But when clicking on the Spinner the preselected Item will again be shown in the drop down and the right.setselection(0) is not executed fast enough so I still see the selected Item for about 0.5sec... Is there an other/easier way to perform this?

you can add
android:prompt=" >>"
in xml and in java set default position in spinner to be -1.

After selecting items in the Spinner, it is not getting reflected to me (not visible to naked eye)

I am working on a project in which I need to dynamically add TextView and Spinner as well. I was able to add these two things dynamically from my program successfully.
Now when I was trying to select some items in the Spinner, that items is not getting shown in my emulator but the items that I selected gets shown in the Toast.
Does I need to do anything to make that item selected in Spinner?
for (Map.Entry<String, String> entry : mapColumns.entrySet()) {
spinnerArray = new ArrayList<String>();
final TextView rowTextView = new TextView(cont);
final Spinner spinner = new Spinner(cont);
rowTextView.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
spinner.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
for(String s: entry.getValue().split(",")) {
System.out.println(s);
s = s.replaceAll("[^a-zA-Z0-9]+","");
spinnerArray.add(s);
}
ArrayAdapter<String> spinnerArrayAdapter = new ArrayAdapter<String>(cont, android.R.layout.simple_spinner_dropdown_item, spinnerArray);
rowTextView.setText(entry.getKey());
rowTextView.setTypeface(null, Typeface.BOLD);
spinner.setAdapter(spinnerArrayAdapter);
// add the listener
spinner.setOnItemSelectedListener(new CustomOnItemSelectedListener());
layout.addView(rowTextView);
layout.addView(spinner);
}
class CustomOnItemSelectedListener implements OnItemSelectedListener {
public void onItemSelected(AdapterView<?> parent, View view, int pos,
long id) {
Toast.makeText(
parent.getContext(),
"OnItemSelectedListener : "
+ parent.getItemAtPosition(pos).toString(),
Toast.LENGTH_SHORT).show();
}
#Override
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
}
}
Below is my XML Layout-
<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/llayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<Button
android:id="#+id/button1"
android:layout_width="100px"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical|center_horizontal|center"
android:gravity="center_vertical|center_horizontal"
android:text="Save" />
</LinearLayout>
</ScrollView>
Here mapColumns will hev Key-Value pair. So in the Spinner all the items are getting shown from the Value of that map.
Problem Statement:-
Now I need to make sure if anybody is selecting any items in the Spinner, it should get selected and be visible to other person.
Below is the image in which I have selected items in the Spinner but it is not getting shown and also TextView is also very light in color-

The below code which you are using to populate the spinnerArray looks suspicious because it will remove all the characters from the string.
for(String s: entry.getValue().split(",")) {
///System.out.println(s); move this print statement to below line and see what it prints in your logs
s = s.replaceAll("[^a-zA-Z0-9]+","");
System.out.println(s);
spinnerArray.add(s);
}
So if the spinnerArray is provided with empty string it will come up with empty spinner. I would suggest comment out the whole block and then try your app and see if the problem persist.
If you want the spinner to comeup with a selected item then add the following line:
spinner.setSelection (0);

Formatting Specific Parts of a Listview Item

So in my application I am using a ListView to display data from an ArrayList which holds objects. The data is displayed using the same method as the tutorial on the android developer website:
// automatically adds a ListView to fill the entire screen of this activity
setListAdapter(new ArrayAdapter<Part>(this, R.layout.list_item, Main.parts));
ListView lv = getListView();
// allows the user to start typing to filter the list
lv.setTextFilterEnabled(true);
// set the click listener for each list item
lv.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
Toast.makeText(getApplicationContext(), ((TextView) view).getText(), Toast.LENGTH_SHORT).show();
}
});
The objects are currently displayed in each list_item:
<!-- Defines the layout for each item being placed in the ListView. -->
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="10dp"
android:textSize="16sp" >
</TextView>
So I return each object as such:
public String toString() {
return "Item Number: " + itemNmbr + "\nPrice: " + price + "\nDescription: " + desc;
}
An example of how the list currently looks:
http://imageshack.us/photo/my-images/689/devicet.png/
The problem is, I need to format the title separately from the data. (because it needs to be bold, and possibly spaced out a little further.)
Any ideas? I'm currently testing on how to get two textviews to work together.
Thank you!

I would recommend using a custom adapter extending BaseAdapter.
http://developer.android.com/reference/android/widget/BaseAdapter.html
See this link for an example.
http://www.softwarepassion.com/android-series-custom-listview-items-and-adapters/