Android java imagebutton example

The value of android:onClick attribute must be the name of method which we need to call in response to a click event and the Activity file which hosting XML layout must implement the corresponding method.

Following is the example of defining a button click event using android:onClick attribute in XML layout file.

< LinearLayout xmlns: android = "http://schemas.android.com/apk/res/android"
android :orientation= «vertical» android :layout_width= «match_parent»
android :layout_height= «match_parent» >
< ImageButton
android :id= «@+id/addBtn»
android :layout_width= «wrap_content»
android :layout_height= «wrap_content»
android :src= «@drawable/add_icon»

In Activity that hosts our XML layout file, we need to implement click event method like as shown below

/** Called when the user touches the button */
public void addOperation(View view) // Do something in response to button click
>

Define ImageButton Click Event in Activity File

In android, we can define ImageButton click event programmatically in Activity file rather than XML layout file.

To define button click programmatically, create View.OnClickListener object and assign it to the button by calling setOnClickListener(View.OnClickListener) like as shown below.

ImageButton btnAdd = (ImageButton)findViewById(R.id. addBtn );
btnAdd.setOnClickListener( new View.OnClickListener() public void onClick(View v)

// Do something in response to button click
>
>);
>

This is how we can handle ImageButton click events in android applications based on our requirements.

Android ImageButton Control Attributes

Following are some of the commonly used attributes related to ImageButton control in android applications.

Android ImageButton Control Example

Following is the example of defining a one ImageButton and two EditText controls in LinearLayout to get the data of EditText controls when click on ImageButton in android application.

Create a new android application using android studio and give names as ButtonExample. In case if you are not aware of creating an app in android studio check this article Android Hello World App.

Now open an activity_main.xml file from \res\layout path and write the code like as shown below

activity_main.xml

< LinearLayout xmlns: android = "http://schemas.android.com/apk/res/android"
android :orientation= «vertical» android :layout_width= «match_parent»
android :layout_height= «match_parent» android :id= «@+id/l_layout» >
< TextView
android :id= «@+id/fstTxt»
android :layout_width= «wrap_content»
android :layout_height= «wrap_content»
android :layout_marginLeft= «100dp»
android :layout_marginTop= «150dp»
android :text= «First Number»/>
< EditText
android :id= «@+id/firstNum»
android :layout_width= «wrap_content»
android :layout_height= «wrap_content»
android :layout_marginLeft= «100dp»
android :ems= «10»/>
< TextView
android :id= «@+id/secTxt»
android :layout_width= «wrap_content»
android :layout_height= «wrap_content»
android :text= «Second Number»
android :layout_marginLeft= «100dp»/>
< EditText
android :id= «@+id/secondNum»
android :layout_width= «wrap_content»
android :layout_height= «wrap_content»
android :layout_marginLeft= «100dp»
android :ems= «10»/>
< ImageButton
android :id= «@+id/addBtn»
android :layout_width= «wrap_content»
android :layout_height= «wrap_content»
android :layout_marginLeft= «100dp»
android :src= «@drawable/add_icon»/>

If you observe above code we created one ImageButton, two TextView controls and two EditText controls in XML Layout file.

Once we are done with the creation of layout with required control, we need to load the XML layout resource from our activity onCreate() callback method, for that open main activity file MainActivity.java from \java\com.tutlane.buttonexample path and write the code like as shown below.

MainActivity.java

package com.tutlane.buttonexample;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity @Override
protected void onCreate(Bundle savedInstanceState) super .onCreate(savedInstanceState);
setContentView(R.layout. activity_main );
final EditText firstNum = (EditText)findViewById(R.id. firstNum );
final EditText secNum = (EditText)findViewById(R.id. secondNum );
ImageButton btnAdd = (ImageButton)findViewById(R.id. addBtn );
btnAdd.setOnClickListener( new View.OnClickListener() @Override
public void onClick(View v) if ( firstNum .getText().toString().isEmpty() || secNum .getText().toString().isEmpty())
Toast.makeText(getApplicationContext(), «Please fill all the fields» , Toast. LENGTH_SHORT ).show();
>
else int num1 = Integer.parseInt( firstNum .getText().toString());
int num2 = Integer.parseInt( secNum .getText().toString());
Toast.makeText(getApplicationContext(), «SUM color: #660e7a;»>LENGTH_SHORT ).show();
>
>
>);
>
>

If you observe above code we are calling our layout using setContentView method in the form of R.layout.layout_file_name in our activity file. Here our xml file name is activity_main.xml so we used file name activity_main and we are getting the values from two EditText controls on ImageButton click and performing an addition operation.

Generally, during the launch of our activity, the onCreate() callback method will be called by the android framework to get the required layout for an activity.

Output of Android ImageButton Example

When we run the above example using an android virtual device (AVD) we will get a result like as shown below.

This is how we can use ImageButton control in android applications to perform required operations on ImageButton tap or click based on our requirements.

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