A broadcast receiver is a component that does nothing but receive and react to broadcast announcements. For example, announcements that the timezone has changed, that the battery is low or that the user changed a language preference.All receivers extend the BroadcastReceiver base class. Broadcast receivers do not display a user interface. However, they may start an activity in response to the information they receive, or they may use the NotificationManager to alert the user like(flashing the backlight, vibrating the device, playing a sound)
What is a content provider?
A content provider makes a specific set of the application’s data available to other applications.The content provider extends the ContentProvider base class to implement a standard set of methods that enable other applications to retrieve and store data of the type it controls. However, applications do not call these methods directly. Rather they use a ContentResolver object and call its methods instead.
What is intent?
A class (Intent) describes what a caller desires to do. The caller sends this intent to Android’s intent resolver, which finds the most suitable activity for the intent.
How is nine-patch image different from a regular bitmap?
It is a resizable bitmap resource that can be used for backgrounds or other images on the device. The NinePatch class permits drawing a bitmap in nine sections. The four corners are unscaled; the four edges are scaled in one axis, and the middle is scaled in both axes.
What languages does Android support for application development?
Android applications are written using the Java programming language.
What is a resource?
A user-supplied XML, bitmap, or other file, injected into the application build process, which can later be loaded from code.
What Virtual Machine Android runs on?
Dalvik virtual machine
What is the demand of Mobile Application developers?
Desktop based IT application is present but the mobile is future. All the applications that were made to work only on desk top are being ported to mobile. In the coming 10 years, desktops will be replaced completely with mobile, and then all the applications will be designed mainly for mobile. The demand for mobile based trained engineers are increasing every year. Now after the launch of ipad by Apple, it will be even more. Therefore; the gextgen technology will be nothing else than mobile. The demand is expected to grow 70 folds in the coming 4 years.
Explain about the exceptions of Android?
The following are the exceptions that are supported by Android
* InflateException : When an error conditions are occurred, this exception is thrown
* Surface.OutOfResourceException: When a surface is not created or resized, this exception is thrown
* SurfaceHolder.BadSurfaceTypeException: This exception is thrown from the lockCanvas() method, when invoked on a Surface whose is SURFACE_TYPE_PUSH_BUFFERS
* WindowManager.BadTokenException: This exception is thrown at the time of trying to add view an invalid WindowManager.LayoutParamstoken.
What are the dialog boxes that are supported in android? Explain.
Android supports 4 dialog boxes:
AlertDialog : An alert dialog box supports 0 to 3 buttons and a list of selectable elements, including check boxes and radio buttons. Among the other dialog boxes, the most suggested dialog box is the alert dialog box.
ProgressDialog: This dialog box displays a progress wheel or a progress bar. It is an extension of AlertDialog and supports adding buttons.
DatePickerDialog: This dialog box is used for selecting a date by the user.
TimePickerDialog: This dialog box is used for selecting time by the user.
What is needed to make a multiple choice list with a custom view for each row?
Multiple choice list can be viewed by making the CheckBox android:id value be ?@android:id /text1". That is the ID used by Android for the CheckedTextView in simple_list_item_multiple_choice.