Android Adapter with Spinner Control

  • Android Spinner allows you to select an item from a drop down menu list. It provides a quick way to select one value from a set.
  • Android Spinner class is the subclass of AsbSpinner class.
  • Android Spinner provides an easy way to select value from list.
  • It shows its currently selected value with all other available values from which the user can select a new one.

    • For example:
    android spinner example

  • In the above example, it displays a dropdown list which indicates the category of phone number. When user touches the spinner, it displays a dropdown menu with all other available values from which the user can selects one.
  • This class is like the dropdown menu with multiple values from which the end user can select only one value.

    • android spinner

  • In the above figure, an Adapter works as a bridge between DataSource (Array, ArrayList etc.) and AdapterView. Some of the important objects of AdapterView are Spinner, ListView and GridView.
  • The user can add a spinner to his/her layout with the Spinner object.

    • For example
    <Spinner
            android:id=”@+id/planets_spinner”
            android:layout_width=“fill_parent”
            android:layout_height=“wrap_content” />

  • SpinnerAdapter is used to populate the spinner with a list of choices. The user then needs to specify this in his/her Activity or Fragment source code.
  • The Spinner is associated with AdapterView. User needs to use one of the adapter classes with Spinner.

Example

Following example demonstrates Spinner Class demo and displays the dropdown list of days.

File Name: strings.xml

<resources>
<string name = "app_name">SpinnerDemo</string>
<string name = "action_settings">Settings</string>
        <string-array name = "Days">
                <item>Sunday</item>
                <item>Monday</item>
                <item>Tuesday</item>
                <item>Wednesday</item>
                <item>Thursday</item>
                <item>Friday</item>
                <item>Saturday</item>

        </string-array>
</resources>

File Name: content_main.xml

<?xml version = "1.0" encoding = "utf-8"?>
<RelativeLayoutxmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app = "http://schemas.android.com/apk/res-auto"
xmlns:tools = "http://schemas.android.com/tools"
android:layout_width = "match_parent"
android:layout_height = "match_parent"
android:paddingBottom = "@dimen/activity_vertical_margin"
android:paddingLeft = "@dimen/activity_horizontal_margin"
android:paddingRight = "@dimen/activity_horizontal_margin"
android:paddingTop = "@dimen/activity_vertical_margin"
app:layout_behavior = "@string/appbar_scrolling_view_behavior"
tools:context = "com.example.custom.spinnerdemo.MainActivity"
tools:showIn = "@layout/activity_main">

<Spinner
android:layout_width = "wrap_content"
android:layout_height = "wrap_content"
android:id = "@+id/spinner"
android:layout_alignParentTop = "true"
android:layout_alignParentLeft = "true"
android:layout_alignParentStart = "true" />
</RelativeLayout>

File Name: MainActivity.java

public class MainActivity extends AppCompatActivity
{
     Spinner spinner;
     @Override
     protected void onCreate(Bundle savedInstanceState)
     {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
          Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
          setSupportActionBar(toolbar);
          spinner = (Spinner) findViewById(R.id.spinner);
          ArrayAdapter adapter = ArrayAdapter.createFromResource(this,
  R.array.Days, android.R.layout.simple_spinner_item);
          spinner.setAdapter(adapter);
          spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener()
          {
               @Override
               public void onItemSelected (AdapterView parent, View view, intposition, long id)
               {
                    TextView txt = (TextView)view;
                    Toast toast = Toast.makeText(getApplicationContext(), "Selected day ="+txt.getText(), Toast.LENGTH_LONG);
                    toast.setGravity(Gravity.CENTER,0,0);
                    toast.show();
               }
               @Override
               public void onNothingSelected (AdapterView parent)
               {

               }
          });
     }
}


Output:

spinner output
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