Spinner drop-down list in Android (implemented using Arrayadapter and custom adapter).

Today I learned the spinner component, using spinner as the equivalent of selecting a project from the drop-down list, the following shows the use of spinner (using Arrayadapter and custom adapter implementations respectively)

(a): Use Arrayadapter to fit data:

①: First define a layout file:

<span style= "FONT-SIZE:16PX;" ><?xml version= "1.0" encoding= "Utf-8"? ><linearlayout xmlns:android= "http://schemas.android.com/apk/ Res/android "    android:layout_width=" fill_parent "    android:layout_height=" fill_parent "    android:o rientation= "vertical" >    <spinner        android:id= "@+id/spinner1" android:layout_width= "Match_        Parent "        android:layout_height=" wrap_content "      /></linearlayout></span>

"Note:" The above spinner has two properties 1:prompt is the initial time, spinner displays the data, is a reference type 2:entries is to bind the data source directly in the XML layout file (can not be set, that can be dynamically bound in the activity)

②: Create a data source, use an array, and the data will be displayed in the spinner down list:

<span style= "FONT-SIZE:16PX;" ><?xml version= "1.0" encoding= "Utf-8"?><resources> <string-array    name= "Spinnername" >        <item> Beijing </item>        <item> Shanghai </item>        <item> Guangzhou </item>        <item > shenzhen </item>    </string-array></resources></span>

③: Then add the following code to the activity ( using a system-defined drop-down list of layout files, of course, can also be customized)

               Initialize control Mspinner = (Spinner) Findviewbyid (r.id.spinner1);//Establish data source string[] Mitems = Getresources (). Getstringarray ( R.array.spinnername);//Establish Adapter and bind the data source arrayadapter<string> _adapter=new arrayadapter<string> (This, Android. R.layout.simple_spinner_item, Mitems);//Bind Adapter to control Mspinner.setadapter (_adapter);

The above code initially completed, to see the effect of the operation:

Here is a click event about spinner (for example):

        Mspinner.setonitemselectedlistener (New Onitemselectedlistener () {@Overridepublic void onitemselected (Adapterview <?> parent, View view,int position, long id) {String str=parent.getitematposition (position). ToString (); Toast.maketext (Spinneractivity.this, "You clicked:" +str, "). Show ();} @Overridepublic void onnothingselected (adapterview<?> parent) {//TODO auto-generated Method stub}});

(ii) Use of custom adapter (emphasis)

①: Define a layout file for 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/text View1 "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: Establish the Person class:

Package Com.jiangqq.csdn;public class Person {private string personname;private string personaddress;public person ( String personname, String personaddress) {super (); this.personname = Personname;this.personaddress = personaddress;} Public String Getpersonname () {return personname;} public void Setpersonname (String personname) {this.personname = PersonName;} Public String getpersonaddress () {return personaddress;} public void setpersonaddress (String personaddress) {this.personaddress = personaddress;}}

③: Create Myadapter inheritance and baseadapter to fit:

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;private Context mcontext;public Myad Apter (Context pContext, list<person> pList) {this.mcontext = Pcontext;this.mlist = pList;} @Overridepublic int GetCount () {return mlist.size ();} @Overridepublic Object getItem (int position) {return mlist.get (position);}    @Overridepublic long Getitemid (int position) {return position;} /** * Below is important code */@Overridepublic view GetView (int position, view Convertview, ViewGroup parent) {Layoutinflater _la Youtinflater=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 control Mspinner = (Spinner) Findviewbyid (r.id.spinner1);//Establish data source    list<person> persons=new ArrayList  <Person> ();p ersons.add (New person ("Zhang San", "Shanghai"));p Ersons.add (New person ("John Doe", "Shanghai");p Ersons.add ("New Person" ("Harry "," Beijing "));p Ersons.add (New Person (" Zhao Liu "," Guangzhou "));//  Establish adapter bound data source Myadapter _myadapter=new Myadapter (This, persons) ;//Binding Adaptermspinner.setadapter (_myadapter);

The results are as follows:

Spinner drop-down list in Android (implemented using Arrayadapter and custom adapter).