A simple list application in Android

I thought using list in Android should be a simple task, but -- I am wrong! I have been reading books, followed by book examples.ProgramI learned to write a list, but I still have no skills. Today, I suddenly saw a video tutorial, and I felt a little confused. This video tutorial is www.mars-droid.com, beginners can download learning, or very good, painted color! Haha ~

Now, let's get started.

In the android program, the use of listview is relatively complex. You not only need to add a listview in the activity for the entire list, but also need a layout file, the layout file controls the display mode of each record (each row) in the listview. For example, a listview contains records of several rows, but each row has multiple fields. How to control these fields is what the layout file needs to handle.

1. Main activity layout:

In the main activity window, you only need to simply add a listview to the activity and set the attributes of the listview.

2. layout of each item in listview:

We use an XML layout file to control the layout of each item. For example, the following XML file places two textviews on each item.

Item. xml

 <  Linearlayout
  Android: layout_height  = "Fill_parent"   
Android: layout_width  = "Fill_parent"   
Android: paddingbottom  = "1dip"   
Android: paddingleft  = "10dip"   
Android: paddingright  = "10dip"   
Android: paddingtop = "1dip"  >  
  <  Textview
  Android: ID  = "@ + ID/user_name"   
Android: layout_width  = "180dip"   
Android: layout_height  = "30dip"  
Android: textsize  = "10pt"  
Android: singleline  = "True"    />  
  <  Textview
  Android: ID  = "@ + ID/user_num"   
Android: layout_width  = "Fill_parent"   
Android: layout_height  = "Fill_parent"  
Android: gravity  = "Right"  
Android: textsize  = "10pt"    />  
  </  Linearlayout  > 

3. Java class of listview

Sets the primary activity to inherit from the listactivity class.

Store the display data of listview through an arraylist

Create a simpleadapter instance and bind the setlistadapter instance to the current listactivity.

Set the action to be performed when each item is clicked.

Myactivity. Java

Public     Class  Myactivity  Extends  Listactivity {
@ Override
  Public     Void  Oncreate (bundle savedinstancestate ){
  Super  . Oncreate (savedinstancestate );
Setcontentview (R. Id. Main );

Arraylist  <  Hashmap  < String, string  >  List  =     New  Arraylist  <  Hashmap  <  String, string  >  ();
Hashmap  <  String, string  >  Map1 =     New  Hashmap  <  String, string  >  ();
Hashmap  <  String, string  >  MAP2  =     New  Hashmap  < String, string  >  ();
Hashmap  <  String, string  >  Map3  =     New  Hashmap  <  String, string  >  ();
Map1.put (  " User_name  "  ,  "  Allen  "  );
Map1.put (  "  User_num  "  ,  "  123  "  );
Map2.put (  "  User_name "  ,  "  Bobo  "  );
Map2.put (  "  User_num  "  ,  "  456  "  );
Map3.put (  "  User_name  " ,  "  David  "  );
Map3.put (  "  User_num  "  ,  "  789  "  );
List. Add (map1 );
List. Add (MAP2 );
List. Add (map3 );

Simpleadapter listadapter  =     New Simpleadapter (
  This  ,  //  Context  
  List,  //  Bound Data Source  
  R. layout. item,  //  Item layout File  
   New  String [] {  "  User_name  "  ,  "  User_num  "  },  //  Column name of listview  
    New    Int  [] {R. Id. user_name, R. Id. user_num });  //  Position of each widget in item  
  
Setlistadapter (listadapter );
}

@ Override
  Protected     Void  Onlistitemclick (listview L, view V,  Int  Position,  Long  ID ){
  // Todo auto-generated method stub  
    Super  . Onlistitemclick (L, V, position, ID );
}
} 

This example is the most basic example program of listview. It can be better applied only by understanding the principle. As for the programCodeThe explanation, don't shift the door to make an axe, you are free to download the video inside the www.mars-droid.com to see, it explains in more detail. The file name is 201701_13_common control file (32.16.mp4)