An overview of. Fully updated for Android Studio Arctic Fox, the goal of this book is to teach the skills necessary to develop Android-based applications using the Java programming language. An overview of Android Studio is included covering areas such as tool windows, the code editor, and the Layout Editor tool. An introduction. Fully updated for Android Studio Arctic Fox, the goal of this book is to teach the skills necessary to develop Android-based applications using the Kotlin programming language.
Beginning with the basics, this book provides an outline of the steps necessary to set up an Android development and testing environment followed. This book covers the basic and advanced topics with equivalent simplicity and detail, in order to enable readers to quickly grasp and implement the concepts to build an application database.
This book takes a hands-on, example-based approach to help readers understand the core topics of SQLite and Android database-driven applications. This book focuses on providing you with latent as well as widespread knowledge about practices and approaches towards development in an easily understandable manner. Total books QlikView Essentials. Redis Essentials. More specifically SQLiteDatabaseprovides the insert , update and delete methods. The "key" represents the table column identifier and the "value" represents the content for the table record in this column.
ContentValues can be used for inserts and updates of database entries. Table 1. Parameters of the query method Parameter Comment String dbName The table name to compile the query against. String[] A list of which table columns to return. Passing "null" will return all columns. These placeholders will get replaced by the values selectionArgs from the selectionArgs array.
String[] groupBy A filter declaring how to group rows, null will cause the rows to not be grouped. String[] having Filter for the groups, null means no filter. String[] orderBy Table columns which will be used to order the data, null means no ordering. If a condition is not required you can pass null, e. If you specify placeholder values in the where clause via? Cursor A query returns a Cursorobject.
A Cursor represents the result of a query and basically points to one row of the query result. This way Android can buffer the query results efficiently; as it does not have to load all data into memory. To get the number of elements of the resulting query use the getCount method. To move between individual data rows, you can use the moveToFirst and moveToNext methods. The isAfterLast method allows to check if the end of the query result has been reached.
The "columnIndex" is the number of the column you are accessing. Cursoralso provides the getColumnIndexOrThrow String method which allows to get the column index for a column name of the table. A Cursorneeds to be closed with the close method call.
ListActivitiesare specialized activities which make the usage of ListViewseasier. You also define an array which contains the column names and another array which contains the IDs of Viewswhich should be filled with the data. To obtain the Cursoryou should use the Loaderclass. Database Synchronization www. Introduction to the project The following demonstrates how to work with an SQLite database.
We will use a data access object DAO to manage the data for us. The DAO is responsible for handling the database connection and for accessing and modifying the data. It will also convert the database objects into real Java Objects, so that our user interface code does not have to deal with the persistence layer.
The resulting application will look like the following. Using a DAO is not always the right approach. A DAO creates Java model objects; using a database directly or via a ContentProvideris typically more resource efficient as you can avoid the creation of model objects.
I still demonstrate the usage of the DAO in this example to have a relatively simple example to begin with. Use the latest version of Android 4. This is currently API Level Otherwise I would have to introduce the Loaderclass, which should be used as of Android 3. And this class introduces additional complexity. Create Project Create the new Android project with the name de. This class is responsible for creating the database.
The onUpgrade method will simply delete all existing data and re-create the table. It also defines several constants for the table name and the table columns. Context; import android. SQLiteDatabase; import android. SQLiteOpenHelper; import android. This class is our model and contains the data we will save in the database and show in the user interface.
This class is our DAO. It maintains the database connection and supports adding new comments and fetching all comments. ArrayList; import java. List; import android. ContentValues; import android. Cursor; import android. SQLException; import android. User Interface Change your main. The comment text will be generated later in the activity by a small random generator. We use here a ListActivity for displaying the data. List; import java.
Random; import android. ListActivity; import android. Bundle; import android. View; import android. Running the apps Install your application and use the Add and Delete button. Restart your application to validate that the data is still there. A SQLite database is private to the application which creates it. If you want to share data with other applications you can use a content provider. A content provider allows applications to access data.
In most cases this data is stored in an SQlite database. While a content provider can be used within an application to access data, its is typically used to share data with other application. As application data is by default private, a content provider is a convenient to share you data with other application based on a structured interface. A content provider must be declared in the AndroidManifest.
Accessing a content provider The access to a content provider is done via an URI. Tip As it is required to know the URIs of an content providersto access it, it is good practice to provide public constants for the URIs to document them to other developers. Many Android datasources, e. Own ContentProvider To create your own ContentProvideryou have to define a class which extends android. You also declare your ContentProviderin the AndroidManifest. An overview of Android Studio is included covering areas such as tool windows, the code editor, and the Layout Editor tool.
Chapters are also included covering the Android Architecture Components including view models, lifecycle management, Room database access, the Database Inspector, app navigation, live data, and data binding. More advanced topics such as intents are also covered, as are touch screen handling, gesture recognition, and the recording and playback of audio.
This edition of the book also covers printing, transitions, cloud-based file storage, and foldable device support. The concepts of material design are also covered in detail, including the use of floating action buttons, Snackbars, tabbed interfaces, card views, navigation drawers, and collapsing toolbars. Assuming you already have some programming experience, are ready to download Android Studio and the Android SDK, have access to a Windows, Mac, or Linux system, and ideas for some apps to develop, you are ready to get started.
Other key features of Android Studio Arctic Fox and Android are also covered in detail including the Layout Editor, the ConstraintLayout and ConstraintSet classes, MotionLayout Editor, view binding, constraint chains, barriers, and direct reply notifications. Beginning with the basics, this book provides an outline of the steps necessary to set up an Android development and testing environment followed by an introduction to programming in Kotlin including data types, control flow, functions, lambdas, and object-oriented programming.
Assuming you already have some programming experience, are ready to download Android Studio and the Android SDK, have access to a Windows, Mac, or Linux system, and have ideas for some apps to develop, you are ready to get started. Beginning with the basics, this book provides an outline of the steps necessary to set up an Android development and testing environment followed by an introduction to programming in Kotlin including data types, flow control, functions, lambdas, and object-oriented programming.
An introduction to the architecture of Android is followed by an in-depth look at the design of Android applications and user interfaces. More advanced topics such as database management, content providers, services and intents are also covered, as are touch screen handling, gesture recognition, camera access and the playback and recording of both video and audio.
Assuming you already have some Java programming experience, are ready to download Eclipse and the Android SDK, have access to a Windows, Mac or Linux system and ideas for some apps to develop, you are ready to get started.
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