Create an application that will Demonstrate ButtononClick() Event and change the TextView Color based on button Clicked

Activity_Main.xml:

<RelativeLayoutxmlns: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"

tools:context=".MainActivity">

<TextView

android:id="@+id/textView1"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignParentTop="true"

android:layout_centerHorizontal="true"

android:layout_marginTop="40dp"

android:text="@string/l1"

android:background="@color/black"

android:textAppearance="?android:attr/textAppearanceLarge" />

<Button

android:id="@+id/button1"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignParentLeft="true"

android:layout_below="@+id/textView1"

android:layout_marginLeft="44dp"

android:layout_marginTop="92dp"

android:text="@string/b1" />

<Button

android:id="@+id/button2"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignBottom="@+id/button1"

android:layout_marginLeft="62dp"

android:layout_toRightOf="@+id/button1"

android:text="@string/b2" />

<Button

android:id="@+id/button3"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignLeft="@+id/button1"

android:layout_below="@+id/button1"

android:layout_marginTop="40dp"

android:text="@string/b3" />

<Button

android:id="@+id/button4"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignBaseline="@+id/button3"

android:layout_alignBottom="@+id/button3"

android:layout_alignLeft="@+id/button2"

android:text="@string/b4" />

</RelativeLayout>

MainActivity.java

package com.example.prac14;

importandroid.os.Bundle;

importandroid.annotation.SuppressLint;

importandroid.app.Activity;

importandroid.view.Menu;

importandroid.view.View;

importandroid.view.View.OnClickListener;

importandroid.widget.Button;

importandroid.widget.TextView;

@SuppressLint("ResourceAsColor")

publicclassMainActivityextends Activity implementsOnClickListener {

            Button b1,b2,b3,b4;

    @Override

protectedvoidonCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

        b1=(Button)findViewById(R.id.button1);

        b2=(Button)findViewById(R.id.button2);

        b3=(Button)findViewById(R.id.button3);

        b4=(Button)findViewById(R.id.button4);

b1.setOnClickListener(this);

b2.setOnClickListener(this);

b3.setOnClickListener(this);

b4.setOnClickListener(this);

    }

    @Override

publicbooleanonCreateOptionsMenu(Menu menu) {

getMenuInflater().inflate(R.menu.activity_main, menu);

returntrue;

    }

            @SuppressLint("ResourceAsColor")

            @Override

            publicvoidonClick(View v) {

                       

                        TextView txt = (TextView )findViewById(R.id.textView1);

                        switch(v.getId())

                        {

                        case R.id.button1:

                                    txt.setBackgroundColor(getResources().getColor(R.color.red));

                                    break;

                        case R.id.button2:

                                    txt.setBackgroundColor(getResources().getColor(R.color.yellow));

                                    break;

                        case R.id.button3:

                                    txt.setBackgroundColor(getResources().getColor(R.color.green));

                                    break;

                        case R.id.button4:

                                    txt.setBackgroundColor(getResources().getColor(R.color.orange));

                                    break;

                        default:

                                   

                       

                        }

                       

                       

            }

}