ListView usage Examples of Android controls _android

This example describes the ListView usage of the Android control. Share to everyone for your reference. Specifically as follows:

Example one:

ListView is a more commonly used component in Android development, showing specific content in a list and being able to display it adaptively according to the length of the data.

Main.xml Layout file:

<?xml version= "1.0" encoding= "Utf-8"?> <linearlayout android:id=
"@+id/linearlayout01"
  android: Layout_width= "Fill_parent" android:layout_height= "fill_parent"
  xmlns:android= "http://schemas.android.com/" Apk/res/android ">
  <listview android:layout_width=" wrap_content "
    android:layout_height=" Wrap_ Content " 
    android:id=" @+id/mylistview ">
  </ListView>
</LinearLayout>

My_listitem.xml Layout file:

<?xml version= "1.0" encoding= "Utf-8"?> <linearlayout "android:layout_width="
  xmlns: Android= "http://schemas.android.com/apk/res/android"
  android:orientation= "vertical" 
  android:layout_ height= "Wrap_content"
  android:id= "@+id/mylistitem" 
  android:paddingbottom= "3dip"
  android: paddingleft= "10dip" >
  <textview android:layout_height= "wrap_content"
    android:layout_width= "Fill_" Parent " 
    android:id=" @+id/itemtitle "
    android:textsize=" 20dip ">
  </TextView>
  < TextView android:layout_height= "wrap_content" android:layout_width= fill_parent "android:id=" @+id/ 
    Itemtext ">
  </TextView>
</LinearLayout>

Lsactivity class:

Package com.ljq.ls;
Import java.util.ArrayList;
Import Java.util.HashMap;
Import java.util.List;
Import android.app.Activity;
Import Android.os.Bundle;
Import Android.widget.ListView;
Import Android.widget.SimpleAdapter;
  public class Lsactivity extends activity {private ListView list = null;
    public void OnCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate);
    Setcontentview (R.layout.main);
    List = (ListView) Findviewbyid (R.id.mylistview);
    Organization Data source list 

The results of the operation are shown in the following illustration:

Example two:

Directory structure

Main.xml Layout file:

<?xml version= "1.0" encoding= "Utf-8"?>
<!--use relative layouts--> <relativelayout xmlns:android=
  " Http://schemas.android.com/apk/res/android "
  android:orientation=" vertical " 
  android:layout_width=" Wrap_ Content "
  android:layout_height=" wrap_content ">
  <textview android:layout_width=" 100dip
    " android:layout_height= "Wrap_content"
    android:layout_marginleft= "30dip"
    android:textsize= "20dip"
    Android:id= "@+id/id"/>
  <textview android:layout_width= "100dip" android:layout_height= "
    wrap_" Content "
    android:layout_aligntop=" @id/id "
    android:layout_torightof=" @id/id "
    android:textsize=" 20dip "
    android:id=" @+id/name "/>
  <textview android:layout_width=" Wrap_content "
    android: layout_height= "Wrap_content"
    android:layout_aligntop= "@id/name"
    android:layout_torightof= "@id/name"
    android:textsize= "20dip"
    android:id= "@+id/age"/>
</RelativeLayout>

Entity JavaBean:

Package com.ljq.domain;
public class Person {
  private String ID;
  private String name;
  Private String age;
  Public person () {
    super ();
  }
  Public person (string ID, string name, String age) {
    super ();
    This.id = ID;
    this.name = name;
    This.age = age;
  }
  Public String GetId () {return
    ID;
  }
  public void SetId (String id) {
    this.id = ID;
  }
  Public String GetName () {return
    name;
  }
  public void SetName (String name) {
    this.name = name;
  }
  Public String Getage () {return age
    ;
  }
  public void Setage (String age) {
    this.age = age;
  }
}

Custom Adapter Personadapter

Package com.ljq.ls;
Import java.util.List;
Import Com.ljq.domain.Person;
Import Android.content.Context;
Import Android.view.LayoutInflater;
Import Android.view.View;
Import Android.view.ViewGroup;
Import Android.widget.ArrayAdapter;
Import Android.widget.TextView;
 /** * ListView Load Adapter Process * * 1, first determine how many data items adapter, based on this data to determine how many item * * 2, to determine the number of each item in the view * * 3, in the view to download the data to display * * * * @author Jiqinlin * */public class Personadapter extends arrayadapter{private Layoutinflater Layoutinflater =
  Null
  private list<person> persons; Public Personadapter (context, int textviewresourceid, List objects) {Super (context, Textviewresourceid, objec
    TS);
    Layoutinflater = Layoutinflater.from (context);
  Persons = objects;
  /** * Get how many data items in adapter/@Override public int GetCount () {return persons.size ();
  @Override public Object getitem (int position) {return persons.get (position); @Override public long getitemid (int position) {return position;
   /** * Create the displayed data interface * Adapter is the bridge between the ListView interface and the data, * when each item in the list is displayed to the page, the adapter GetView method is invoked to return a view. Did you ever think about it? What will it look like when we have 1000000 items in our list?
   Is it taking up a lot of system resources? * * @Override public View getview (int position, View Convertview, ViewGroup parent) {///Pre Viewholder
    Holder = new Viewholder ();
    Convertview = layoutinflater.inflate (R.layout.main, NULL);
    Holder.id = (TextView) Convertview.findviewbyid (r.id.id);
    Holder.name = (TextView) Convertview.findviewbyid (r.id.name);
    Holder.age = (TextView) Convertview.findviewbyid (r.id.age);
    Convertview.settag (holder);
    Holder.id.setText (Persons.get (position). GetId ());
    Holder.name.setText (Persons.get (position). GetName ());
    Holder.age.setText (Persons.get (position). Getage ());
    return convertview;
    *///optimized after Viewholder holder;
      if (Convertview = = null) {Convertview = layoutinflater.inflate (R.layout.main, NULL);
      Holder = new Viewholder ();Holder.id = (TextView) Convertview.findviewbyid (r.id.id);
      Holder.name = (TextView) Convertview.findviewbyid (r.id.name);
      Holder.age = (TextView) Convertview.findviewbyid (r.id.age);
    Convertview.settag (holder);
    }else{holder = (viewholder) convertview.gettag ();
    } holder.id.setText (Persons.get (position). GetId ());
    Holder.name.setText (Persons.get (position). GetName ());
    Holder.age.setText (Persons.get (position). Getage ());
  return convertview;
    /** * Interface Display control * * @author jiqinlin * */private static class viewholder{private TextView ID;
    private TextView name;
  Private TextView age;

 }
}

Class Lsactivity

Package com.ljq.ls;
Import java.util.ArrayList;
Import android.app.ListActivity;
Import Android.os.Bundle;
Import Android.view.View;
Import Android.widget.ListView;
Import Android.widget.Toast;
Import Com.ljq.domain.Person;
  public class Lsactivity extends Listactivity {private arraylist<person> persons = new arraylist<person> ();
  Private Personadapter personadapter = null;
    
    @Override public void OnCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate);
    InitData ();
    Personadapter =new personadapter (lsactivity.this, r.layout.main, persons);
    Setlistadapter (Personadapter);
  Registerforcontextmenu (Getlistview ()); @Override protected void Onlistitemclick (ListView l, View v, int position, long id) {Super.onlistitemclick (L, V
    , position, id);
    Person person = persons.get (position); Toast.maketext (Lsactivity.this, Person.getid () + ":" +person.getname () + ":" +person.getage (), Toast.length_long). Show
    ();
Return  private void InitData () {Persons.add (New person ("ordinal", "name", "Age"));
    Persons.add (New Person ("1", "ljq1", "20"));
    Persons.add (New Person ("2", "LJQ2", "20"));
    Persons.add (New Person ("3", "Ljq3", "20"));
    Persons.add (New Person ("4", "Ljq4", "20"));
    Persons.add (New Person ("5", "Ljq5", "20"));
    Persons.add (New Person ("6", "Ljq6", "20"));
    Persons.add (New Person ("7", "Ljq7", "20"));
    Persons.add (New Person ("8", "Ljq8", "20"));
  Persons.add (New Person ("9", "Ljq9", "20"));
 }
}

Run results

I hope this article will help you with your Android program.