![]() ![]() Tell the adapter a layout to display it in Set the adapter in the listview. We can use a SimpleCursorAdapter (or CursorAdapter) to display the information 4.widget for support before 3.0 Basics: Get the data in a cursor There must be a column called _id and it’s an unique integer. Using ListViews to display information from databases makes a lot of sense. Ģ3 References Creating an using Databases with android Android TutorialsĪndroid Tutorials Some good general help Android developer siteĢ4 Cursors, Listviews, Expandablelistview, and adapters For example: SELECT * FROM table_name The output format is pretty ugly, but workable. In a command line using the adb (Android Debug Bridge - found in the android sdk tools library) you can access the databases on a running emulator like below adb -s emulator-5554 shell assuming 5554 is your emulator sqlite3 /data/data/package_name/databases/database_name After this you can type normal SQL commands to test the content. The system stores databases in the /data/data/package_name/databases folder by default. Public class mySQLiteHelper extends extends SupportSQLiteOpenHelper.Callback db.close() Remember these are the variable name for the column names, so if we decide to change the column names, we don’t have Search through the code to change them.īring up the logcat or "run" There will you give a way to debug your app, including what caused Check the log for Errors (in red) Transactions are used to make sure the database is always in a sensible state. You create a subclass implementing onCreate(SQLiteDatabase), onUpgrade(SQLiteDatabase, int, int) and optionally onOpen(SQLiteDatabase) This class takes care of opening the database if it exists, creating it if it does not, and upgrading it as necessary. These should be a separate class, for easy of use later.ĥ Extend SupportSQLiteOpenHelper.CallbackĪ helper class to manage database creation and version management. Using the notifies setup in the contentProvider The data will be updated in the background and displayed in the listview. This is also very you set constants for the column names, table names, etc. ![]() And if the structure of the database changes, it upgrades the database (ie any tables that need changed). It is the one that actually creates the database and the table(s) in the database. We will be using the androidx version, add to app adle implementation 'androidx.sqlite:sqlite:2.0.1' implementation 'androidx.sqlite:sqlite-framework:2.0.1'ģ SQLite and Android Package The Model The controller:Ī.SupportSQLiteDatabase The Model “Database” class SupportSQLiteOpenHelper class The controller: Declares a local variable for the database class With large amounts of data, this can slow the UI, so it should be done in AsyncTask (or thread) Or uses the content provider to access/change the data Access with loaders (built in threads) and an AsyncTask for rest.Ĥ SQLiteOpenHelper This is simple but very important class that you need to extend. Import android.widget.1 SQLite Cursors, adapters With Content Providers as well.Ĭosc 5/4730 SQLite Cursors, adapters With Content Providers as well.Ģ SQLite For the sql language syntax, please see SQlite documentation Step 3 − Create a new kotlin class CustomExpandableListAdapter.kt and add the following code − Example import Step 2 − Add the following code to res/layout/activity_main.xml. Step 1 − Create a new project in Android Studio, go to File? New Project and fill all required details to create a new project. ![]() ![]() This example demonstrates how to create a Expandable listView using Kotlin. ![]()
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