Android Custom Spinner Drop-down list (implemented using Arrayadapter and custom adapter) _android

Today, I learned the use of spinner components, a very useful component, the equivalent from the Drop-down list to select items, today a lot of harvest, the following to show you the use of spinner (respectively using Arrayadapter and custom adapter implementation), the specific contents are as follows.

(i): Use of Arrayadapter for data adaptation:

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, spinner display of data, is a reference type 2:entries is directly in the XML layout file binding data source (you can not set, that is, can be dynamically bound in the activity)

②: Set up a data source, using an array, which will be displayed in the spinner 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 (the layout file using the system-defined Drop-down list, of course, can be customized)

    Initializes the control
Mspinner = (Spinner) Findviewbyid (r.id.spinner1);
Set up 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 completes initially, looks down the operation effect:

The following is a click event on spinner (the effect is shown above):

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, "What you clicked is:" +str). Show ();
  @Override public
  void onnothingselected (adapterview<?> parent) {
    //TODO auto-generated method stub
  }
});

(ii) Use of customized 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:o" rientation= "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:

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 Myada
  Pter extends Baseadapter {private list<person> mlist;
  Private 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; /** * Below is an important code * * @Override public View getview (int position, View Convertview, ViewGroup parent) {Layou
    Tinflater _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:

 Initializes the control
Mspinner = (Spinner) Findviewbyid (r.id.spinner1);
Establish the data source
list<person> persons=new arraylist<person> ();
Persons.add (New person ("John", "Shanghai"));
Persons.add (New person ("Dick", "Shanghai"));
Persons.add (New person ("Harry", "Beijing"));
Persons.add (New Person ("Zhao Liu", "Guangzhou"));
Establish adapter bound data source
myadapter _myadapter=new Myadapter (this, persons);
Binding Adapter
Mspinner.setadapter (_myadapter);

The results of the operation are screenshot: