Android Development (3)

Keywords:sqlite database , ListView, data adapter, content provider

SQLite Database : Sqliteopenhelper class; sqlitedatabase;

SQLITEOPENHELPER:A Helper class to manage database creation and version management.

Sqlitedatabase:exposes methods to manage a SQLite database.

The relationship between the two: Sqlitedatabase db = Helper.getwritabledatabase ();

Contentvalues: Adding and deleting the database is the data stored in the contentvalues;

Conmands: (SQL Statement implementation Additions and deletions)

Insert into account (Name,money) VALUES (string,string)

SELECT * FROM Account

Update account Set money = ' + ' where id= ' 1 '

Delete from account where id= ' 1

System API implementation and additions and changes

Db.insert (), Db.update () ...

Database transactions: Bank Transfer For example, let both sides change the value of the database at the same time to take effect

db.begintransaction ();    Try  {     ...     Db.settransactionsuccessful ();    finally {     db.endtransaction ();   

ListView:

1. Custom data adapters: Inherit the Baseadapeter class;

   View view=view.inflate (mainactivity.  thisnull);

   Convert the XML file into a View object as a unit of the ListView.

2. Arrayadapter:
3. Simpleadapter:simpleadapter more complex points, the inside of the unit can have a variety of forms

content providers: to Be continued

Android Development (3)