Android Layoutinflater Detailed

It is still very useful to layoutinflater this class in real-world development, which acts like Findviewbyid (). The difference is that Layoutinflater is used to find the XML layout file under res/layout/and is instantiated, while Findviewbyid () is looking for specific widget controls (such as button, TextView, and so on) under the XML layout file. Specific role: 1, for a non-loaded or want to dynamically load the interface, you need to use Layoutinflater.inflate () to load, 2, for an already loaded interface, you can use Activiyt.findviewbyid () method to obtain the interface elements. Layoutinflater is an abstract class that is declared in the document as follows:

Public abstract class Layoutinflater extends Object

Three ways to get Layoutinflater instances

1. Layoutinflater inflater = Getlayoutinflater ();//Invoke Activity's Getlayoutinflater () 2. Layoutinflater Inflater = layoutinflater.from (context);  3. Layoutinflater inflater =  (layoutinflater) Context.getsystemservice (Context.layout_inflater_service);

In fact, these three ways are essentially the same, from the source can be seen: Getlayoutinflater (): Activity of the Getlayoutinflater () method is called Phonewindow Getlayoutinflater () method , take a look at the source code:

Public Phonewindow (Context context) {    super (context);       Mlayoutinflater = Layoutinflater.from (context);}

It can be seen that it is actually called layoutinflater.from (context). Layoutinflater.from (context):

public static Layoutinflater from (context context) {    Layoutinflater layoutinflater = (layoutinflater) Context.getsystemservice (context.layout_inflater_service);    if (Layoutinflater = = null)    {            throw new Assertionerror ("Layoutinflater not Found.")       ;       return layoutinflater;}

It can be seen that it actually calls Context.getsystemservice (). Conclusion: So the final essence of these three methods is all called Context.getsystemservice (). Another Getsystemservice () is an important API for Android, a method of activity that obtains the corresponding object according to the name passed in, and then translates it into the corresponding service object. The following describes the system's corresponding services. The name passed in Description of the returned object

Window_service WindowManager Manage open Windows program Layout_inflater_service Layoutinflater get the Viewactivity_service defined in the XML Activitymanager Management Application System State Power_service Powermanger power supply Service alarm_service alarmmanager Alarm service Notification_service Notificationmanager Service of the status bar Keyguard_service keyguardmanager the service location_service Locationmanager location of the keyboard lock, such as Gpssearch_ Service Searchmanager Search Services Vebrator_service vebrator phone Vibrate service connectivity_service Connectivity Network connection service Wifi_service Wifimanager Wi-Fi service telephony_service Teleponymanager Telephony service Inflate method through the SDK API documentation, you can know that the method has the following overload forms, the return value is the View object, As follows: public view inflate (int. resource, ViewGroup root) public view inflate (Xmlpullparser parser, ViewGroup root) public Vie  W Inflate (Xmlpullparser parser, ViewGroup root, Boolean attachtoroot) public View inflate (int resource, ViewGroup root,       Boolean attachtoroot) schematic code: Layoutinflater inflater = (layoutinflater) getsystemservice (Layout_inflater_service); View view = Inflater.inflate (R.layout.custom, (ViewGroup) Findviewbyid (r.id.teST)); EditText EditText = (EditText) Findviewbyid (r.id.content);//error EditText EditText = (EditText) View.findviewbyid ( R.id.content); For the above code, specify the second parameter ViewGroup root, and of course you can set it to a null value.

Note: The inflate method differs from the Findviewbyid method, Inflater is used to find the XML layout file under Res/layout, and is instantiated, and Findviewbyid () is to find specific widget controls in the specific XML layout file ( such as: Button, TextView, etc.).

Android Layoutinflater Detailed