In Android, the Spinner drop-down list (implemented using ArrayAdapter and custom Adapter) and android custom spinner

[Go to] a menu bar for customizing the ArrayAdapter and custom Adapter in Android.

Today, I learned about the Spinner component. Using the Spinner component is equivalent to selecting a project from the drop-down list. The following describes how to use IT (using ArrayAdapter and custom Adapter respectively)

(1): Use ArrayAdapter for data adaptation:

①: First define a layout file:

 

 1 <span style="font-size:16px;"><?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3     android:layout_width="fill_parent" 4     android:layout_height="fill_parent" 5     android:orientation="vertical" > 6   7     <Spinner 8         android:id="@+id/spinner1" 9         android:layout_width="match_parent"10         android:layout_height="wrap_content"11       />12 </LinearLayout></span>

 

[Note:] The above spin NER has two attributes: 1. When the prompt is initial, the data displayed by the spin NER is a reference type 2: entries is directly bound to the data source in the xml layout file (you can dynamically bind the data source in the Activity without setting it)

②: Create a data source and use an array. The data will be displayed in the list of the Spinner:

 

1 <span style = "font-size: 16px;"> <? Xml version = "1.0" encoding = "UTF-8"?> 2 <resources> 3 <string-array name = "spinnername"> 4 <item> Beijing </item> 5 <item> Shanghai </item> 6 <item> Guangzhou </ item> 7 <item> Shenzhen </item> 8 </string-array> 9 </resources> </span>

 

③: Add the following code to the Activity (the layout file of the drop-down list defined by the system can also be customized)

 

 

 

 

// Initialize the control mSpinner = (Spinner) findViewById (R. id. spinner1); // create a data source String [] mItems = getResources (). getStringArray (R. array. spinnername); // create an Adapter and bind it to the data source ArrayAdapter <String> _ Adapter = new ArrayAdapter <String> (this, android. r. layout. simple_spinner_item, mItems); // bind the Adapter to the control mSpinner. setAdapter (_ Adapter );

 

 

 

The above code is initially completed. Check the running effect:

The following is a click event (for example) about the Spinner ):

 

 

 

MSpinner. setOnItemSelectedListener (new OnItemSelectedListener () {@ Override public void onItemSelected (AdapterView <?> Parent, View view, int position, long id) {String str = parent. getItemAtPosition (position ). toString (); Toast. makeText (SpinnerActivity. this, "you click:" + str, 2000 ). show () ;}@ Override public void onNothingSelected (AdapterView <?> Parent) {// TODO Auto-generated method stub }});

 

(2) Use a custom Adapter (important)

①: Define the layout file of each Item

 

 

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="horizontal" >     <TextView        android:id="@+id/textView1"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:drawableLeft="@drawable/ic_launcher"        android:paddingRight="8dip"        android:paddingTop="8dip"        android:text="TextView"        android:textSize="25sp" />     <TextView        android:id="@+id/textView2"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:paddingLeft="8dip"        android:paddingTop="8dip"        android:text="TextView"        android:textSize="25sp" /> </LinearLayout>

 

②: Create the Person class:

 

 

 1 package com.jiangqq.csdn; 2 public class Person { 3     private String personName; 4     private String personAddress; 5     public Person(String personName, String personAddress) { 6         super(); 7         this.personName = personName; 8         this.personAddress = personAddress; 9     }10     public String getPersonName() {11         return personName;12     }13     public void setPersonName(String personName) {14         this.personName = personName;15     }16     public String getPersonAddress() {17         return personAddress;18     }19     public void setPersonAddress(String personAddress) {20         this.personAddress = personAddress;21     }22  23 }

 

③ Create MyAdapter inheritance and BaseAdapter for adaptation:

 

 

Package com. jiangqq. csdn; import java. util. list; import android. content. context; import android. view. layoutInflater; import android. view. view; import android. view. viewGroup; import android. widget. baseAdapter; import android. widget. textView;/*** custom adapter class * @ author jiangqq <a href = http://blog.csdn.net/jiangqq781931404> </a> **/public class MyAdapter extends BaseAdapter {private List <Person> mList; privat E Context mContext; public MyAdapter (Context pContext, List <Person> pList) {this. mContext = pContext; this. mList = pList;} @ Override public int getCount () {return mList. size () ;}@ Override public Object getItem (int position) {return mList. get (position) ;}@ Override public long getItemId (int position) {return position ;}/ *** The following is the important code */@ Override public View getView (int position, view convert View, ViewGroup parent) {LayoutInflater _ LayoutInflater = LayoutInflater. from (mContext); convertView = _ LayoutInflater. inflate (R. layout. item, null); if (convertView! = Null) {TextView _ TextView1 = (TextView) convertView. findViewById (R. id. textView1); TextView _ TextView2 = (TextView) convertView. findViewById (R. id. textView2); _ TextView1.setText (mList. get (position ). getPersonName (); _ TextView2.setText (mList. get (position ). getPersonAddress ();} return convertView ;}}

 

④: Add the following code to the Activity:

 

 

// Initialize the control mSpinner = (Spinner) findViewById (R. id. spinner1); // create a data source List <Person> persons = new ArrayList <Person> (); persons. add (new Person ("Zhang San", "Shanghai"); persons. add (new Person ("Li Si", "Shanghai"); persons. add (new Person ("Wang Wu", "Beijing"); persons. add (new Person ("Zhao ", "Guangzhou"); // create an Adapter to bind the data source MyAdapter _ MyAdapter = new MyAdapter (this, persons); // bind AdaptermSpinner. setAdapter (_ MyAdapter );

 

The running effect is as follows:

The listening event is the same as the first method: