How to set Spinner default value to null

Question

I m trying to get a Spinner to load up with no selected value  Once the user selects a value it then takes them to another page    This is proving to be a problem because at present  the page just loads straight away before the user gets a choice to choose   My spinner class is set up the same way as Google s  http   developer android com resources tutorials views hello-spinner html  So basically  is it possible have a spinner that loads with nothing selected because at present  it loads the first item in my string array

User · Answer

Merge this   private long previousItemId   0    Override public long getItemId int position        long nextItemId   random nextInt Integer MAX VALUE       while previousItemId    nextItemId            nextItemId   random nextInt Integer MAX VALUE             previousItemId   nextItemId      return nextItemId      With this answer   public class SpinnerInteractionListener         implements AdapterView OnItemSelectedListener  View OnTouchListener        private AdapterView OnItemSelectedListener onItemSelectedListener       public SpinnerInteractionListener AdapterView OnItemSelectedListener selectedListener            this onItemSelectedListener   selectedListener             boolean userSelect   false        Override     public boolean onTouch View v  MotionEvent event            userSelect   true          return false              Override     public void onItemSelected AdapterView lt   gt  parent  View view  int pos  long id            if userSelect                onItemSelectedListener onItemSelected parent  view  pos  id               userSelect   false                        Override     public void onNothingSelected AdapterView lt   gt  parent            if userSelect                onItemSelectedListener onNothingSelected parent               userSelect   false

User · Answer

Alternatively  you could override your spinner adapter  and provide an empty view for position 0 in your getView method  and a view with 0dp height in the getDropDownView method   This way  you have an initial text such as  Select an Option     that shows up when the spinner is first loaded  but it is not an option for the user to choose  technically it is  but because the height is 0  they can t see it

User · Answer

you can put the first cell in your array to be empty      some   some        and do nothing if the position is 0   public void onItemSelected AdapterView lt   gt  parent  View view  int position  long id        if position gt 0            label setText MainActivity questions position - 1               if you fill the array by xml file you can let the first item empty

User · Answer

I assume that you want to have a Spinner with first empty invisible item  that is a strange feature of Spinner that cannot show a list without selecting an item   You should add a class that will contain data   data class YourData val id  Int  val name  String     This is the adapter   class YourAdapter      context  Context      private val textViewResourceId  Int      private var items  ArrayList lt YourData gt      ArrayAdapter lt YourData gt  context  textViewResourceId  items         private var inflater  LayoutInflater   context getSystemService          Context LAYOUT INFLATER SERVICE  as LayoutInflater      override fun getCount    Int   items size   1      override fun getItem position  Int   YourData            if  position    0  YourData 0      else items position - 1       override fun getItemId position  Int   Long   position toLong        override fun getView position  Int  convertView  View   parent  ViewGroup   View           if  position    0                getFirstTextView convertView            else               getTextView convertView  parent  position - 1                 override fun getDropDownView position  Int  convertView  View   parent  ViewGroup   View           getView position  convertView  parent       private fun getFirstTextView convertView  View    View              Just simple TextView as initial selection          var textView  TextView    convertView as  TextView         val holder  FirstViewHolder         if  textView  tag  is FirstViewHolder                textView   TextView context     inflater inflate R layout your text  parent  false  as TextView             textView height   0    Hide first item              holder   FirstViewHolder               holder textView   textView             textView tag   holder                   return textView            private fun getTextView          convertView  View           parent  ViewGroup          position  Int        TextView           var textView  TextView    convertView as  TextView         val holder  ViewHolder         if  textView  tag is ViewHolder                holder   textView tag as ViewHolder           else               textView   inflater inflate textViewResourceId  parent  false  as TextView             holder   ViewHolder               holder textView   textView             textView tag   holder                   holder textView text   items position  name          return textView            private class FirstViewHolder           lateinit var textView  TextView            private class ViewHolder           lateinit var textView  TextView           To create    YourAdapter context    R layout text item  ArrayList      To add items   private fun fill items  List lt YourData gt   adapter  YourAdapter        adapter run           clear           addAll items          notifyDataSetChanged             When you load items to your Spinner with that fill   command  you should know  that indices are also incremented  So if you wish to select 3rd item  you should now select 4th  spinner  setSelection index   1

User · Answer

Using a custom spinner layout like this     lt  xml version  1 0  encoding  utf-8   gt   lt Spinner xmlns android  http   schemas android com apk res android            android id    id spinnerTarget            android layout width  fill parent            android layout height  wrap content            android textSize  14dp                     android textColor   000000   gt    In the activity          populate the list     ArrayList lt String gt  dataList   new ArrayList lt String gt         for  int i   0  i  lt  4  i              dataList add  Item                  set custom layout spinner layout xml and adapter     Spinner spinnerObject    Spinner  findViewById R id spinnerObject       ArrayAdapter lt String gt  dataAdapter   new ArrayAdapter lt String gt  this  R drawable spinner layout  dataList       dataAdapter setDropDownViewResource android R layout simple spinner dropdown item       spinnerObject setAdapter dataAdapter       spinnerObject setOnTouchListener new View OnTouchListener               public boolean onTouch View v  MotionEvent event                   to set value of first selection  because setOnItemSelectedListener will not dispatch if the user selects first element             TextView spinnerTarget    TextView v findViewById R id spinnerTarget               spinnerTarget setText spinnerObject getSelectedItem   toString                  return false                         spinnerObject setOnItemSelectedListener new AdapterView OnItemSelectedListener                     private boolean selectionControl   true                   public void onItemSelected AdapterView lt   gt  parent  View view  int pos  long id                           just the first time                     if selectionControl                               find TextView in layout                          TextView spinnerTarget    TextView parent findViewById R id spinnerTarget                              set spinner text empty                         spinnerTarget setText                              selectionControl   false                                            else                             select object                                                          public void onNothingSelected AdapterView lt   gt  parent

User · Answer

This is a complete implementation of Paul Bourdeaux s idea  namely returning a special initial view  or an empty view  in getView   for position 0   It works for me and is relatively straightforward  You might consider this approach especially if you already have a custom adapter for your Spinner   In my case  I was using custom adapter in order to easily customise the layout of the items  each item having a couple of TextViews    The adapter would be something along these lines   public class MySpinnerAdapter extends ArrayAdapter lt MyModel gt         public MySpinnerAdapter Context context  List lt MyModel gt  items            super context  R layout my spinner row  items               Override     public View getDropDownView int position  View convertView   NonNull ViewGroup parent            if  position    0                return initialSelection true                     return getCustomView position  convertView  parent               NonNull      Override     public View getView int position  View convertView   NonNull ViewGroup parent            if  position    0                return initialSelection false                     return getCustomView position  convertView  parent                Override     public int getCount             return super getCount     1     Adjust for initial selection item            private View initialSelection boolean dropdown               Just an example using a simple TextView  Create whatever default view             to suit your needs  inflating a separate layout if it s cleaner          TextView view   new TextView getContext             view setText R string select one           int spacing   getContext   getResources   getDimensionPixelSize R dimen spacing smaller           view setPadding 0  spacing  0  spacing            if  dropdown       Hidden when the dropdown is opened             view setHeight 0                      return view             private View getCustomView int position  View convertView  ViewGroup parent               Distinguish  real  spinner items  that can be reused  from initial selection item         View row   convertView    null  amp  amp    convertView instanceof TextView             convertView           LayoutInflater from getContext    inflate R layout my spinner row  parent  false            position   position - 1     Adjust for initial selection item         MyModel item   getItem position                   Resolve views  amp  populate with data              return row             That s it  Note that if you use a OnItemSelectedListener with your Spinner  in onItemSelected   you d also have to adjust position to take the default item into account  for example   if  position    0        return    else       position   position - 1    MyModel selected   items get position

User · Answer

In my case  although size  2  is displayed in the spinner  nothing happens till some selection is done   I have an xml file  data sizes xml  which lists all the spinner values    lt  xml version  1 0  encoding  utf-8   gt   lt resources gt       lt string-array name  chunks  gt           lt item gt 2 lt  item gt           lt item gt 4 lt  item gt           lt item gt 8 lt  item gt           lt item gt 16 lt  item gt           lt item gt 32 lt  item gt       lt  string-array gt   lt  resources gt        In main xml file  Spinner element   lt Spinner android id    id spinnerSize    android layout marginLeft  50px  android layout width  fill parent                    android drawSelectorOnTop  true  android layout marginTop  5dip  android prompt   string SelectSize  android layout marginRight  30px  android layout height  35px    gt     Then in my java code  I added   In my activity  Declaration  Spinner spinnerSize  ArrayAdapter adapter    In a public void function - initControls    Definition  spinnerSize    Spinner findViewById R id spinnerSize   adapter   ArrayAdapter createFromResource this  R array chunks  android R layout simple spinner item   adapter setDropDownViewResource android R layout simple spinner dropdown item   spinnerSize setAdapter adapter   spinnerSize setOnItemSelectedListener new MyOnItemSelectedListener       My spinner listener      Spinner Listener     class MyOnItemSelectedListener implements OnItemSelectedListener        public void onItemSelected AdapterView lt   gt  parent          View view  int pos  long id            chunkSize   new Integer parent getItemAtPosition pos  toString    intValue              public void onNothingSelected AdapterView lt   gt  parent             Dummy

User · Answer

is it possible have a spinner that loads with nothing selected   Only if there is no data  If you have 1  items in the SpinnerAdapter  the Spinner will always have a selection   Spinners are not designed to be command widgets  Users will not expect a selection in a Spinner to start an activity  Please consider using something else  like a ListView or GridView  instead of a Spinner     EDIT  BTW  I forgot to mention -- you can always put an extra entry in your adapter that represents  no selection   and make it the initial selected item in the Spinner

User · Answer

My solution  in case you have a TextView as each row of the spinner          TODO  add a fake item as the last one of  items      final ArrayAdapter lt String gt  adapter new ArrayAdapter lt String gt        items                  Override       public View getDropDownView final int position final View convertView final ViewGroup parent                    final View dropDownView super getDropDownView position convertView parent             TextView dropDownView findViewById android R id text1   setHeight position  getCount  -1 0 getDimensionFromAttribute    R attr dropdownListPreferredItemHeight            dropDownView getLayoutParams   height position  getCount  -1 0 LayoutParams MATCH PARENT          return dropDownView                                 spinner setAdapter adapter        actionModeSpinnerView setSelection dataAdapter getCount  -1 false        public static int getDimensionFromAttribute final Context context final int attr            final TypedValue typedValue new TypedValue        if context getTheme   resolveAttribute attr typedValue true         return TypedValue complexToDimensionPixelSize typedValue data context getResources   getDisplayMetrics         return 0

User · Answer

Base on  Jonik answer I have created fully functional extension to ArrayAdapter   class SpinnerArrayAdapter lt T gt    ArrayAdapter lt T gt         private val selectText   String     private val resource  Int     private val fieldId   Int     private val inflater   LayoutInflater      constructor context  Context   resource  Int  objects  Array lt T gt   selectText   String    null    super context  resource  objects            this selectText   selectText    context  getString R string spinner default select text                this resource   resource         this fieldId   0         this inflater   LayoutInflater from context            constructor context  Context   resource   Int  objects  List lt T gt   selectText   String    null    super context  resource  objects            this selectText   selectText    context  getString R string spinner default select text                this resource   resource         this fieldId   0         this inflater   LayoutInflater from context            constructor context  Context   resource  Int  textViewResourceId  Int  objects  Array lt T gt   selectText   String    null    super context  resource  textViewResourceId  objects            this selectText   selectText    context  getString R string spinner default select text                this resource   resource         this fieldId   textViewResourceId         this inflater   LayoutInflater from context            constructor context  Context   resource   Int  textViewResourceId  Int  objects  List lt T gt   selectText   String    null    super context  resource  textViewResourceId   objects            this selectText   selectText    context  getString R string spinner default select text                this resource   resource         this fieldId   textViewResourceId         this inflater   LayoutInflater from context             override fun getDropDownView position  Int  convertView  View   parent  ViewGroup    View           if position    0                return initialSelection true                     return createViewFromResource inflater  position -1  convertView  parent  resource             override fun getView position  Int  convertView  View   parent  ViewGroup    View           if position    0                return initialSelection false                    return createViewFromResource inflater  position -1  convertView  parent  resource             override fun getCount    Int           return super getCount     1    adjust for initial selection            private fun initialSelection inDropDown  Boolean    View              Just simple TextView as initial selection          val view   TextView context          view setText selectText          view setPadding 8  0  8  0           if inDropDown                   Hide when dropdown is open             view height   0                   return view            private fun createViewFromResource inflater  LayoutInflater  position  Int                                          Nullable convertView  View   parent  ViewGroup   resource  Int   View           val view  View         val text  TextView           if  convertView    null     convertView is TextView                 view   inflater inflate resource  parent  false            else               view   convertView                    try               if  fieldId     0                        If no custom field is assigned  assume the whole resource is a TextView                 text   view as TextView               else                       Otherwise  find the TextView field within the layout                 text   view findViewById fieldId                   if  text    null                        throw RuntimeException  Failed to find view with ID                                 context getResources   getResourceName fieldId                                  in item layout                                             catch  e  ClassCastException                Log e  ArrayAdapter    You must supply a resource ID for a TextView               throw IllegalStateException                       ArrayAdapter requires the resource ID to be a TextView   e                     val item   getItem position          if  item is CharSequence                text text   item           else               text text   item   toString                      return view

[android] How to set Spinner default value to null?

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