It's a very basic example to implement onClickListener for Button:
- Button A, define onClickListener as anonymous class.
- Button B1 and B2: define onClickListener class.
- Button C1 and C2: assign callback function in XML.
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:id="@+id/background"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="16dp"
android:orientation="vertical"
android:onClick="onBackgroundClickedCallback"
tools:context="com.blogspot.android_er.androidclicklistener.MainActivity">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:autoLink="web"
android:text="http://android-er.blogspot.com/"
android:textStyle="bold" />
<Button
android:id="@+id/buttona"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Button A: anonymous onClickListener"/>
<Button
android:id="@+id/buttonb1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Button B1: onClickListener"/>
<Button
android:id="@+id/buttonb2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Button B2: onClickListener"/>
<Button
android:id="@+id/buttonc1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="onClickCallback"
android:text="Button C1: define callback in XML"/>
<Button
android:id="@+id/buttonc2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick="onClickCallback"
android:text="Button C2: define callback in XML"/>
<TextView
android:id="@+id/info"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="28dp"/>
</LinearLayout>
MainActivity.java
package com.blogspot.android_er.androidclicklistener;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
Button btnA, btnB1, btnB2, btnC1, btnC2;
TextView textInfo;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnA = (Button)findViewById(R.id.buttona);
btnB1 = (Button)findViewById(R.id.buttonb1);
btnB2 = (Button)findViewById(R.id.buttonb2);
btnC1 = (Button)findViewById(R.id.buttonc1);
btnC2 = (Button)findViewById(R.id.buttonc2);
textInfo = (TextView) findViewById(R.id.info);
btnA.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(MainActivity.this,
"Button A Clicked: implement anonymous onClickListener",
Toast.LENGTH_LONG).show();
textInfo.setText(v.toString());
}
});
btnB1.setOnClickListener(btnBOnClickListener);
btnB2.setOnClickListener(btnBOnClickListener);
}
//set by calling setOnClickListener()
View.OnClickListener btnBOnClickListener = new View.OnClickListener() {
@Override
public void onClick(View v) {
if(v.getId() == R.id.buttonb1){
Toast.makeText(MainActivity.this,
"Button B1 Clicked: implement onClickListener",
Toast.LENGTH_LONG).show();
}else if((v.getId() == R.id.buttonb2)){
Toast.makeText(MainActivity.this,
"Button B2 Clicked: implement onClickListener",
Toast.LENGTH_LONG).show();
}
textInfo.setText(v.toString());
}
};
//define in XML
public void onClickCallback(View v){
if(v.getId() == R.id.buttonc1){
Toast.makeText(MainActivity.this,
"Button C1 Clicked: callback assign in XML",
Toast.LENGTH_LONG).show();
}else if((v.getId() == R.id.buttonc2)){
Toast.makeText(MainActivity.this,
"Button C2 Clicked: callback assign in XML",
Toast.LENGTH_LONG).show();
}
textInfo.setText(v.toString());
}
//define in XML
public void onBackgroundClickedCallback(View v){
Toast.makeText(MainActivity.this,
"Background Clicked",
Toast.LENGTH_LONG).show();
textInfo.setText(v.toString());
}
}
