Top WCF SDK Interview Questions & Answers:

1. What is SDK (Software development kit)?

A software development kit is typically a set of software development tools that allows the creation of applications for a certain software package, software framework, hardware platform, computer system, video game console, operating system, or similar development platform.

2. 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!");
intent.setType("vnd.android-dir/mms-sms");
startActivity(intent);

3. Described the Services component of Android?

Services are components that do not have a User Interface; they run in the background. An example of Service component in Facebook app would be the friend request notifications. They would continue to run, even if you switch to another activity or application.

4. Described Broadcast receiver component of Android?

A Broadcast receiver comes into action only in specific situations. Suppose an Intent for which a particular broadcast receiver has been registered occurs, the broadcast receiver is triggered into action and the user gets a notification for the same. (For example: Battery low notification).

5. What are the different data storage options which are available in Android?

Different data storage options are available in Android are:
★ SharedPreferences
★ SQlite
★ ContentProvider
★ File Storage
★ Cloud Storage

6. What are 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.

7. Described 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.

8. Define 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

<uses-permissionandroid:name="android.permission.SEND_SMS"/>

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).

9. Described 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.

10. Described 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.