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.
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.
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!");
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
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).
★ 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.
★ 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.
AIDL supports following data types:
★ All native Java data types like int,long, char and Boolean
★ 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.
Android Architecture consists of 4 key components:
★ Linux Kernel
★ Android Framework
★ Android Applications