1. Describe the android activities?

Activity provides the user interface. When you create an android application in eclipse through the wizard it asks you the name of the activity. Default name is MainActivity. You can provide any name according to the need. Basically it is a class (MainActivity) that is inherited automatically from Activity class. Mostly, applications have oneor more activities; and the main purpose of an activity is to interact with the user. Activity goes through a numberof stages, known as an activity's life cycle.

2. Define the sending SMS in android?

SMS messaging is one of the basic and important applications on a mobile phone. Now days every mobile phone has SMS messaging capabilities, and nearly all users of any age know how to send and receive such messages. Mobile phones come with a built-in SMS application that enables you to send and receive SMS messages.

3. Tell me how to use built-in messaging within the application?

Intent object to activate the built-in Messaging service. You have to pass MIME type "vnd.android-dir/mms-sms", in setType method of Intent as shown in the following given below code.

Intent intent = new Intent (android.content.Intent.ACTION_VIEW);
intent.putExtra("address", "5556; 5558;");// Send the message to multiple recipient.
itent.putExtra("sms_body", "Hello my friends!");

4. Describe sending SMS messages programmatically?

Take a button on activity_main.xml file as follows.

<Button android:id="@+id/btnSendSMS" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerHorizontal="true" android:layout_centerVertical="true" android:onClick="sendmySMS" android:text="sendSMS" />

According to above code when user clicks the button sendmySMS method will be called. sendmySMS is user defined method.

In the AndroidManifest.xml file, add the following statements


Now we write the final step. Write the given below method in MainActivity,java file

publicvoidsendmySMS(View v)
SmsManagersms = SmsManager.getDefault();
sms.sendTextMessage("5556", null, "Hello from google", null, null);
In this example I have used two emulator. On the first Android emulator (5554), click the Send SMSbutton to send an SMS message to the second emulator(5556).

5. Define activity creator in Android?

★ An activity Creator is the initial step for creation of a new Android project.
★ It consists of a shell script that is used to create new file system structure required for writing codes in Android IDE.

6. Define Dalvik Virtual Machine?

★ It is Android's virtual machine.
★ It is an interpreter-only virtual machine which executes files in Dalvik Executable (.dex) format. This format is optimized for efficient storage and memory-mappable execution.

7. Tell me what data types are supported by AIDL?

AIDL supports following data types:
★ String
★ List
★ Map
★ CharSequence
★ All native Java data types like int,long, char and Boolean

8. Define AIDL?

★ AIDL is the abbreviation for Android Interface Definition Language.
★ It handles the interface requirements between a client and a service to communicate at the same level through inter-process communication.
★ The process involves breaking down objects into primitives that are Android understandable.

9. List the key components of Android Architecture?

Android Architecture consists of 4 key components:
★ Linux Kernel
★ Libraries
★ Android Framework
★ Android Applications

10. List the application of shared preference?

★ Storing the information about number of visitors (counter).
★ Storing the date and time (when your Application is updated).
★ Storing the username and password.
Storing the user settings.

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