Android Button Click Listeners

Android Button Click Listeners :

Android Button Click Listeners : Android button control consists of text and a background color or draw-able which response upon touching it. Android Button control has android.widget as its base class. It can be used to response on clicking on it by user.

You can have onClickListener, onLongClickListener. Also you can define the method name in the xml layout file itself.

Below design and code describes both listeners of Android button control and how to define on click method from design file itself.

activity_main.xml :

<?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:background="#fff"
 android:orientation="vertical" >

<TextView
 android:id="@+id/txtView1"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_gravity="center"
 android:layout_margin="2dp"
 android:padding="5dp"
 android:text="Hello, I&apos;m a simple Android Textview control."
 android:textColor="#ff0000"
 android:textSize="16sp" />

<Button
 android:id="@+id/btnClickHere"
 android:layout_width="160dp"
 android:layout_height="50dp"
 android:layout_gravity="center_horizontal"
 android:layout_margin="5dp"
 android:background="@android:drawable/btn_default"
 android:padding="5dp"
 android:text="CLICK HERE"
 android:textColor="#000"
 android:textSize="16sp"
 android:typeface="monospace" />

<Button
 android:id="@+id/btnDesignMethod"
 android:layout_width="160dp"
 android:layout_height="50dp"
 android:layout_gravity="center_horizontal"
 android:layout_margin="5dp"
 android:background="@drawable/greenbutton"
 android:onClick="DesignMethod"
 android:padding="5dp"
 android:text="CLICK HERE"
 android:textColor="#000"
 android:textSize="16sp"
 android:typeface="monospace" />

</LinearLayout>

This is a basic layout file, wherein I have made a text view along with two buttons. Both buttons will response differently on click them. The first button btnClickHere will be having two listeners, one for onClickListener and other for onLongClickListeners. The second button will be having a simple toast message. Difference between both of them is, first button’s click listeners are defined in code file whereas for the later, method is defined in design view itself.

Create a new java class file with name TextActivity.java and Edit it as below :

TextActivity.java:

package parallelcodes.simplewidget;

import android.app.Activity;
 import android.os.Bundle;
 import android.view.View;
 import android.widget.Button;
 import android.widget.TextView;
 import android.widget.Toast;

public class TextActivity extends Activity {
 Button btnDesignMethod, btnClickHere;
 TextView txtView1;
 int i = 0;
 int j = 0;

@Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);

txtView1 = (TextView) findViewById(R.id.txtView1);

btnClickHere = (Button) findViewById(R.id.btnClickHere);

btnClickHere.setOnClickListener(new View.OnClickListener() {

@Override
 public void onClick(View v) {
 // TODO Auto-generated method stub
 i++;
 txtView1.setText("You clicked : " + String.valueOf(i)
 + " times.");

}
 });

btnClickHere.setOnLongClickListener(new View.OnLongClickListener() {

@Override
 public boolean onLongClick(View v) {
 j++;
 txtView1.setText("You Long pressed : " + String.valueOf(j)
 + " times.");
 return true;
 }
 });

}

public void DesignMethod(View v) {
 Toast.makeText(TextActivity.this, "Hi there", Toast.LENGTH_SHORT)
 .show();
 }
 }

AndroidManifest.xml :

<?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
 package="parallelcodes.simplewidget"
 android:versionCode="1"
 android:versionName="1.0" >

<uses-sdk
 android:minSdkVersion="14"
 android:targetSdkVersion="14" />

<application
 android:allowBackup="true"
 android:icon="@drawable/ic_launcher"
 android:label="@string/app_name"
 android:theme="@style/AppTheme" >
 <activity
 android:name=".TextActivity"
 android:label="@string/app_name"
 android:screenOrientation="portrait" >
 <intent-filter>
 <action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />
 </intent-filter>
 </activity>
 </application>

</manifest>

Now let’s see a demo video on the application we just made :

Please also see : Android Beginners Tutorial.