Android

Adroid provides developers with a development platform to build rich and novel applications.ProgramCapabilities. Developers can freely use hardware devices, access local information, run background services, Set alarms, and add notifications on the

It is the default action of the system to retain the activity status when the activity is terminated. In this way, when the user returns to the previous activity, the user interface will display the way they left. However, in the scenario where the

To manage fragment in an activity, you need to use the fragmentmanager object. You can obtain this object by calling the getfragmentmanager () method in the activity. The fragmentmanager object can do the following: 1. Get the existing fragment in

1. inheritance relationship Java. Lang. Object | _____ Android. OS. Message Implement the parcelable interface. 2. class overview This class defines a message that can be sent to the handler object. It contains the Message description and any data

1. inheritance relationship Java. Lang. Object | _____ Android. widget. Toast 2. class overview A toast is a window that contains short messages to remind users. The toast class will help you create and display this window. When this window is

When the activity receives the focus, it will request to describe its layout. The android framework will deal with this plotting process, but the activity must provide its layout hierarchy and nodes. It starts from the root node of the layout. It

Style attributes After understanding how a style is defined, you need to learn that elements define valid style attribute types. You may already be familiar with layout_width and textcolor attributes, but there are more style attributes that can be

Public void settargetfragment (fragment, int requestcode) This method sets an optional target for this fragment object. For example, if this fragment object is started by another fragment object and you want to return a given result to the first

A started service must manage its own lifecycle. That is to say, unless the system needs to recycle the system memory, the system will not terminate or destroy this service. After the onstartcommand () method returns, this service will continue to

The android backup service is integrated into the android data backup framework. It is used to back up and restore data on most devices running Android or later. In some cases, the specific Android device may contain different backup transmitters

This article translated from: http://developer.android.com/guide/topics/renderscript/advanced.html Because the application using renderscript still runs inside the android Virtual Machine (VM), you can access all the framework APIs you are familiar

Put data into the database You can import the contentvalues object into the instert () method to insert data into the database: // Gets the data repository in write modeSqlitedatabase DB = mdbhelper. getwritabledatabase (); // Create a new map of

This article translated from: http://developer.android.com/training/basics/intents/sending.html One of the important features of Android is to bring users into another application based on the specific "action" to be executed. For example, if your

Verify that there is an application to receive intent objects Although the Android platform ensures that the determined intent object will be received by the built-in applications (such as phone, email, calendar, and other applications), before

Call renderscript code You can use _Script_nameCreates an renderscript object and calls renderscript from the android framework code. This class contains a foreach_root () method, which calls the rsforeach () method. You can pass it the same

Use viewpropertyanimator to create an animation The viewpropertyanimator class uses a single animator object to provide a simple method for parallel processing of several animation attributes of a view object. Its behavior is very similar to the

Use valueanimator to create an animation The valueanimator class specifies certain types of animation values during animation playback by setting int, float, or color values during the animation process. Obtain a valueanimator object through a

The loader function is introduced in android3.0, which makes it easy to load data asynchronously in activity or fragment. The loader has the following features: 1. The loader is valid for every activity and fagment; 2. The loader provides the

Public void oncreatecontextmenu (contextmenu menu, view V, contextmenu. contextmenuinfo menuinfo) This method is called when the context menu of the view object is displayed. Unlike oncreateoptionmenu (menu, menuinflater), this method is called

This article translated from: http://developer.android.com/training/sharing/receive.html Just as your application can send data to other applications, it can easily receive data from other applications. When receiving data from other applications,