Create empty Spinner - android

How can I create an empty spinner with no elements in it and add them later?
ArrayAdapter<String> aSpin = ArrayAdapter.createFromResource(this, null , null);
Doesnt work.

I'm curious, in which scenario would you want an empty spinner?
anyway, a spinner with a null object will give you an annoying exception. If you really want a spinner "empty", i would recommend you to create a normal spinner with a fake object. That object would be a string like " ". So, it won't be empty but it will look like if it is.
-- Edit --
In order to use a spinner with objects, you will need an adapter. So, first, if you want an empty spinner, just find its view from your layout and that's all. You will have an empty spinner:
mSpinner = (Spinner)findViewById(R.mLayout.mSpinnerID);
Then, when you need to add your items to the spinner, create an array with those items, then add them to the adapter, and add the adapter to your spinner. For example, let's say that you will have strings:
ArrayList<String> mList = new ArrayList<String>();
mList.add("item 1");
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, mList);
mList.setAdapter(adapter);

An Adapter is something different than a Spinner. If you want to create an empty Spinner, just define one in your layout file or create one programmatically. It will not contain any items if you don't set an Adapter on the Spinner (or specify static entries in the xml declaration).
You might want to take a look at the Spinner tutorial.

Related

Showing only one parameter of custom object in dropdown menu using AutoCompleteTextView

I want to show only one parameter from object(s) found using AutoCompleteTextView. I have list of custom items and I'm using this list in ArrayAdapter which is used in my AutoCompleteTextView. But as I find item by typing something to AutoCompleteTextView, only object as whole is shown (Object type and some identifier), but I want to show just Objects attribute "name" which is a String.
The way i'd go about this is making a separate arraylist with all the names inside of it. Display that and get the user to chose from there, once they have use the index to find the object in the other list.
Initiate new string array
String[] data = new String[1]); // terms is a List<String>
for(int i=0;i<=1;i++){ //only the 1st position of ur data getting inserted
data[0]=s.get(i).toString();
}
ArrayAdapter<?> adapter = new ArrayAdapter<Object>(activity, android.R.layout.simple_dropdown_item_1line, data);
keywordField.setAdapter(adapter); // keywordField is a AutoCompleteTextView

populating spinner using ArrayAdapter

I have a list of custom objects, that I created from downloaded JSON array and I would like to populate the Spinner with just one field from my list, but I still want to keep the whole onItemSelected.
Currently I am doing it like that
ArrayAdapter<Country> myAdapter = new ArrayAdapter<Country>(Prototype_activity.this, android.R.layout.simple_spinner_item, ValueHolder.countryList)
spinner.setAdapter(myAdapter);
spinner.setVisibility(View.VISIBLE);
So how do I say to adapter to use only one field from each item?
...and I would like to populate the Spinner with just one field from my
list, but I still want to keep the whole onItemSelected.
If you are going to use an ArrayAdapter then implement the toString() method for the Country class to return a String representation of the desired field.

can we set pre text in the spinner in android

I am getting all the values from the webservice. Can we set this value by default in my spinner.like pre populated value for update.
we do like that edittext1.setText("");
So can we do same it for spinner.
please help me for this.
Thnak you
no its not possible in spinner. you can't set a title like value in spinner in starting.We have use ArrayAdaper then it will show value that is selected.
Like Spinner.setSelection(position);
Edited to insert data in spinner
Call these code whenever you want to change content of Spinner
first find it by id
Spinner s = (Spinner) findViewById( R.id.unique_id );
and then place this code where ever you want to update spinner data
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
this, R.array.array_name, android.R.layout.simple_spinner_item );
adapter.setDropDownViewResource( android.R.layout.simple_spinner_drop_down_item );
s.setAdapter( adapter );
R.array.array_name is array store in String file in res.you can use your dynamic array too

How to show Spinner selected Item first in Android

In my application i have one spinner with data Cart,Trolley,Lorry,Truck etc..
in a button click i am saving spinner selected item and other items in the data base.
Now in another button click i want to display all saved data,so in that i want to display previously saved spinner item first instead of default one.
How can i achieve this,please anyone suggest me
Ex:in spinner 1,2,3,4 displayed now if i select 3 and saved in data base now this time i want to show spinner data as 3,4,1,2.
It's much simple by getting index of spinner from DB and set the currently selected index on spinner item,for example if the spinner position stored in DB
then set it as
spinner.setSelection(2);// Note : Position starts from 0,1,2,3 on array
You can change spinner content as below
String[] items = new String[] {"3","4", "1","2"};
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_spinner_item, items);
spinner2.setAdapter(adapter);
So I understand you correctly, you want to reorder the spinner items based on the user's previous selection? You just have to update the Adapter that you assigned to the spinner in that case.
I guess you wired up a simple ArrayAdapter in this case, so a basic solution would be to modify the order of the strings contained in that adapter, after selection.
ArrayList listArray = new ArrayList();
listArray.add("one");
listArray.add("two");
listArray.add("three");
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_spinner_item, listArray.toArray(strArray););
spinner2.setAdapter(adapter);
here took items as ArrayList and when user click on any item , break that arraylist in two part start to that point and point to last. then take one temp arraylist and add second part then first part so in that one .
and again call
adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_spinner_item, listArray.toArray(strArray););
spinner2.setAdapter(adapter);

creating autocomplete in android

I want to create a AutoCompleteTextView in android. The problem is that I want to show whole list of data when user selects AutoCompleteTextView and start filtering data as user types the letters.Please help me in doing this.
Well here is an way how you can do that,
declare an String array -
String[] array = new String[]{"first","second","third","fourth"};
Now, initialize the Adapter with the source.
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_dropdown_item_1line,array);
Finally fetch the AutoCompleteTextView id from your xml and set the adapter.
AutoCompleteTextView mView = (AutoCompleteTextView)
findViewById(R.id.myAutoTextView);
mView.setAdapter(adapter);

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