Q8

Question 8

Create an application with 3 buttons vertically aligned, on selecting a button color of the screen will change.

App Insights:

Made a vertical layout for buttons, aligned them and added margin, wrote methods for each button to change bgcolor based on stored values in colors.xml

Browse Source Code

Code

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

    <Button
        android:id="@+id/b1"
        android:layout_width="200dp"
        android:layout_height="75dp"
        android:layout_weight="0"
        android:layout_marginLeft="100dp"
        android:layout_marginTop="75dp"
        android:minWidth="200dp"
        android:onClick="goRed"
        android:text="Red" />

    <Button
        android:id="@+id/b2"
        android:layout_width="200dp"
        android:layout_height="75dp"
        android:layout_weight="0"
        android:layout_marginLeft="100dp"
        android:layout_marginTop="125dp"
        android:onClick="goBlue"
        android:text="Blue" />

    <Button
        android:id="@+id/b3"
        android:layout_width="200dp"
        android:layout_height="75dp"
        android:layout_weight="0"
        android:layout_marginLeft="100dp"
        android:layout_marginTop="125dp"
        android:onClick="goGreen"
        android:text="Green" />


</LinearLayout>

package com.example.q8_three_color_buttons_vertical;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;

public class MainActivity extends AppCompatActivity {
    View view;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        view = this.getWindow().getDecorView();
        view.setBackgroundResource(R.color.gray);
    }
    public void goRed(View v) {
        view.setBackgroundResource(R.color.red);
    }
    public void goBlue(View v) {
        view.setBackgroundResource(R.color.blue);
    }
    public void goGreen(View v) {
        view.setBackgroundResource(R.color.green);
    }
}

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="purple_200">#FFBB86FC</color>
    <color name="purple_500">#FF6200EE</color>
    <color name="purple_700">#FF3700B3</color>
    <color name="teal_200">#FF03DAC5</color>
    <color name="teal_700">#FF018786</color>
    <color name="black">#FF000000</color>
    <color name="white">#FFFFFFFF</color>
    <color name="gray">#616161</color>
    <color name="red">#ff0000</color>
    <color name="blue">#0000ff</color>
    <color name="green">#00ff00</color>
</resources>

Download Q8_Three_Color_Buttons_Vertical.apk to Run and Test Locally

Output

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Last updated 4 years ago