Monday, May 25, 2015

How to change RelativeLayout background color programmatically in Android

activity_main.xml

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/rl"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="16dp"
    tools:context=".MainActivity"
    >
    <Button
        android:id="@+id/btn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Apply Background Color"
        android:layout_centerInParent="true"
        />
</RelativeLayout>
MainActivity.java

package com.cfsuman.me.androidcodesnippets;

import android.graphics.Color;
import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.widget.Button;
import android.widget.RelativeLayout;

public class MainActivity extends Activity{

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

        // Get the widgets reference from XML layout
        final RelativeLayout rl = (RelativeLayout) findViewById(R.id.rl);
        Button btn = (Button) findViewById(R.id.btn);

        // Set a click listener for Button widget
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // Add RelativeLayout background color
                rl.setBackgroundColor(Color.GREEN);

                // Another way to set background color
                //rl.setBackgroundColor(Color.parseColor("#48B5FF"));

                // Background color with transparency
                //rl.setBackgroundColor(Color.parseColor("#AA48B5FF"));
            }
        });
    }
}
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