Android onClick Listener Application

Well on this time we are going to see how to create the application with onClick listener in android.For that we need to create the android application project first.For that double click the eclipse IDE and goto new android application project .

     After that your project will appear in the package Explorer you need to expand the package explorer on that select the src folder and you will get the java code such as MainActivity.java  after that double click the java file.

     Inside  the res folder goto to the layout folder and select the activity_main.Xml file and you need to enter the coding for android onClick listener.Xml is used for UI design so you need to create the button in the xml file.

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="vertical"

> 

    <Button

        android:id="@+id/button1"

        android:layout_width="150dp"

        android:layout_height="50dp"

        android:layout_marginTop="20dp"

        android:layout_marginLeft="90dp"

        android:text="Press to start" />

</LinearLayout>

     Layout is used to split the partition in android.And in the layout you are creating the Button and after that you are assigning the width and size for your button.

     Thats it you have been created the button now you need write the backend process of button by using java code.

     Now open the src folder and MainActivity.java file.Now insert these coding in the java file.

public class Emmozhi extends Activity {

protected void onCreate(Bundle savedInstance)

       {

              super.onCreate(savedInstance);

              setContentView(R.layout.activity_main);

Button main_button=(Button)findViewById(R.id.button_1);

Main_button.setOnClickListener(new View.OnClickListener() {

public void onClick(View arg0) {

Toast.makeToast(getApplicationContent,”you clicked the button”,Toast.LENGTH_LONG).show();

}

             

});

        }

}

     First you are creating the button instance in the oncreate method then you placed the onclick listener for the button using the button object.Once the button clicked it will display this “You clicked the button”congratulation you created the onClickListener application.