Sharon on the 'net

This snippet of code will allow you to customize your WordPress dashboard logo.

The two functions below need to be added to your theme’s functions.php file. Note: before doing so, be sure to change “mysite” to your preferred name.

function mysite_customize_register( $wp_customize ) {
	$wp_customize->add_setting( 'mysite_dashlogo', array( 'default' => '' ) );
	$wp_customize->add_control(
		new wp_Customize_Image_Control(
			$wp_customize,
			'dashlogo',
			array(
				'label'       => __( 'Dashboard Logo', 'mysite' ),
				'section'     => 'title_tagline',
				'settings'    => 'mysite_dashlogo',
				'description' => 'Set a logo for the admin bar',
			)
		)
	);
}
add_action( 'customize_register', 'mysite_customize_register' );

function mysite_admin_dashlogo( $wp_admin_bar ) {
     $dashlogo = get_theme_mod( 'mysite_dashlogo');
     if( !empty( $dashlogo ) ) { ?>
         
     <?php }
 }
 add_action('admin_bar_menu', 'mysite_admin_dashlogo');