Implementation of the Android spinner Control

The screen of the mobile phone is small, so it is a good way to use the drop-down list for selective input. Like ListView, Spinner is an indirect subclass of AdapterView and a window for displaying data. Common Methods of the Spinner class are as follows. getItemAtPosition (Spinner. getSelectedItemPosition (); call the setOnItemSelectedListener () method to obtain the value of the drop-down list box, process the selected event in the drop-down list box, and set AdapterView. the OnItemSelectedListener instance is passed into strings as a parameter. xml [html] <? Xml version = "1.0" encoding = "UTF-8"?> <Resources> <string name = "app_name"> ASpinnerDemo </string> <string name = "hello_world"> Hello world! </String> <string name = "menu_settings"> Settings </string> <string name = "selectStr"> what is your choice? </String> </resources> main. xml [html] www.2cto.com <RelativeLayout xmlns: android = "http://schemas.android.com/apk/res/android" xmlns: tools = "http://schemas.android.com/tools" android: layout_width = "match_parent" android: layout_height = "match_parent" tools: context = ". mainActivity "> <TextView android: id =" @ + id/TextView_Show "android: layout_width =" fill_parent "android: layout_height =" wrap_content "android: t Ext = "@ string/selectStr" android: textSize = "16sp"> </TextView> <Spinner android: id = "@ + id/spinner_City" android: layout_width = "fill_parent" android: layout_marginTop = "50dp" android: layout_height = "wrap_content"> </Spinner> <! -- Define a drop-down menu --> </RelativeLayout> java code implementation [java] package com. example. aspinnerdemo; import java. util. arrayList; import java. util. list; import android. app. activity; import android. OS. bundle; import android. view. motionEvent; import android. view. view; import android. view. menu; import android. widget. adapterView; import android. widget. arrayAdapter; import android. widget. spinner; import android. widget. tex TView; public class MainActivity extends Activity {/** Called when the activity is first created. */private List <String> list = new ArrayList <String> (); private TextView myTextView; private Spinner mySpinner; private ArrayAdapter <String> adapter; @ Override protected void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState); setContentView (R. layout. activity_main); // Step 1: Add a drop-down list List of list items. The items added here are the list of menu items in the drop-down list. add ("Test 1"); list. add ("Test 2"); list. add ("Test 3"); list. add ("Test 4"); list. add ("Test 5"); list. add ("Test 6"); list. add ("Test 7"); list. add ("Test 8"); list. add ("test 9"); myTextView = (TextView) findViewById (R. id. textView_Show); mySpinner = (Spinner) findViewById (R. id. spinner_City); // Step 2: Define an adapter for the drop-down list. The previously defined list is used here. Adapter = new ArrayAdapter <String> (this, android. R. layout. simple_spinner_item, list); // Step 3: Set the menu style in the drop-down list for the adapter. Adapter. setDropDownViewResource (android. r. layout. simple_spinner_dropdown_item); // Step 4: add the adapter to the drop-down list. setAdapter (adapter); // Step 5: Set the event response for the drop-down list. setOnItemSelectedListener (new Spinner. onItemSelectedListener () {public void onItemSelected (AdapterView <?> Arg0, View arg1, int arg2, long arg3) {// TODO Auto-generated method stub/* bring the value of the selected mySpinner to myTextView */myTextView. setText ("You selected:" + adapter. getItem (arg2);/* display mySpinner */arg0.setVisibility (View. VISIBLE);} public void onNothingSelected (AdapterView <?> Arg0) {// TODO Auto-generated method stub myTextView. setText ("NONE"); arg0.setVisibility (View. VISIBLE) ;}});/* content options displayed in the drop-down menu touch-screen event processing */mySpinner. setOnTouchListener (new Spinner. onTouchListener () {public boolean onTouch (View v, MotionEvent event) {// TODO Auto-generated method stub/* hides mySpinner. You can also hide it without hiding it, view your hobbies */v. setVisibility (View. INVISIBLE); return false ;}});/* The content option in the drop-down menu changes the focus of event processing */mySpinner. setOnFocusChangeListener (new Spinner. onFocusChangeListener () {public void onFocusChange (View v, boolean hasFocus) {// TODO Auto-generated method stub v. setVisibility (View. VISIBLE) ;}}) ;}@ Override public boolean onCreateOptionsMenu (Menu menu) {// Inflate the menu; this adds items to the action bar if it is present. getMenuInflater (). inflate (R. menu. activity_main, menu); return true ;}}