<?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="horizontal"
tools:context=".MainActivity">
<Button
android:id="@+id/b1"
android:layout_width="150dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:layout_marginTop="300dp"
android:layout_marginLeft="5dp"
android:layout_marginRight="5dp"
android:minWidth="150dp"
android:onClick="goRed"
android:text="Red" />
<Button
android:id="@+id/b2"
android:layout_width="150dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:layout_marginTop="300dp"
android:layout_marginRight="5dp"
android:minWidth="200dp"
android:onClick="goBlue"
android:text="Blue" />
<Button
android:id="@+id/b3"
android:layout_width="150dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:maxHeight="20dp"
android:layout_marginTop="300dp"
android:layout_marginRight="10dp"
android:onClick="goGreen"
android:text="Green" />
</LinearLayout>
<?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>
package com.example.q9_three_color_buttons_horizontal;
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);
}
}
