Usage of the Spinner in Android (usage of the drop-down list)

Source: Internet
Author: User

Usage of the Spinner in Android (usage of the drop-down list)

Step 2: Write the Spinner drop-down list

To write a Spinner:

1. Set the data source. Use List set to write
2. Create an ArrayAdapter (array adapter)
3. Set a drop-down list Style
4. bind an adapter to a Spinner
5. Set the listener OnItemSelectedListener ()

Use the first one of the two types of Spinner drop-down lists:

Main function:

Public class MainActivity extends AppCompatActivity implements AdapterView. OnItemSelectedListener {private TextView mTextView; private Spinner mSpinner; private List
  
   
List; private ArrayAdapter
   
    
Adapter; @ Override protected void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState); setContentView (R. layout. activity_main); mTextView = (TextView) findViewById (R. id. textview); mSpinner = (Spinner) findViewById (R. id. spinner); // 1. Set the data source list = new ArrayList <> (); list. add (Beijing); list. add (Shanghai); list. add (Qingdao); list. add (Shenzhen); list. add (Chengdu); // create an ArrayAdapter (array adapter) adapter = new ArrayAdapter
    
     
(This, android. r. layout. simple_spinner_item, list); // set a drop-down list style adapter for the adapter. setDropDownViewResource (android. r. layout. simple_spinner_dropdown_item); // loads the adapter mSpinner. setAdapter (adapter); // sets the mSpinner listener. setOnItemSelectedListener (this);} @ Override public void onItemSelected (AdapterView
     Parent, View view, int position, long id) {// obtain the name of the current city // String cityName = list. get (position); String city = adapter. getItem (position); mTextView. setText (the city you select + city);} @ Override public void onNothingSelected (AdapterView
     Parent ){}}
    
   
  

Layout file:


      
       
    
   
  
Second:

Main function:

Public class MainActivity extends AppCompatActivity {private TextView mTextView; private Spinner mSpinner; private SimpleAdapter adapter; private List
  
   
> Datalist; @ Override protected void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState); setContentView (R. layout. activity_main); mTextView = (TextView) findViewById (R. id. textview_main); mSpinner = (Spinner) findViewById (R. id. spinner); // Step 1: Add a list of items in the drop-down list. The items added here are the menu items in the drop-down list datalist = new ArrayList <> (); // Step 2: define an adapter for the drop-down list. The previous list adapter = new SimpleAdapter (this, getData (), R. layout. item, new String [] {image, text}, new int [] {R. id. image, R. id. textview}); // Step 3: Set the menu style adapter in the drop-down list for the adapter. setDropDownViewResource (R. layout. item); // Add the adapter to the mSpinner drop-down list. setAdapter (adapter); // Step 5: Set events for the drop-down list. mSpinner is selected in the Event Response menu. setOnItemSelectedListener (new AdapterView. onItemSelectedListener () {@ Override public void onItemSelected (AdapterView
   Parent, View view, int position, long id) {mTextView. setText (you selected + adapter. getItem (position);} @ Override public void onNothingSelected (AdapterView
   Parent) {mTextView. setText (NONE) ;}} private List
   
    
> GetData () {Map
    
     
Map = new HashMap <> (); map. put (image, R. mipmap. ic_launcher); map. put (text, Beijing); Map
     
      
Map2 = new HashMap <> (); map2.put (image, R. mipmap. ic_launcher); map2.put (text, Chengdu); Map
      
        Map3 = new HashMap <> (); map3.put (image, R. mipmap. ic_launcher); map3.put (text, Shenzhen); Map
       
         Map4 = new HashMap <> (); map4.put (image, R. mipmap. ic_launcher); map4.put (text, Qingdao); Map
        
          Map5 = new HashMap <> (); map5.put (image, R. mipmap. ic_launcher); map5.put (text, Jinan); Map
         
           Map6 = new HashMap <> (); map6.put (image, R. mipmap. ic_launcher); map6.put (text, Hong Kong); datalist. add (map); datalist. add (map2); datalist. add (map3); datalist. add (map4); datalist. add (map5); datalist. add (map6); return datalist ;}}
         
        
       
      
     
    
   
  

 

 

Related Article

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.