Wordpress get post ID from Widget - wordpress

Question

I am trying to get the post ID outside the loop from a widget, but I get some another page ID instead the current post ID.
My question similar to wordpress get post id from side widget, but the accepted answer here (add add_action("widgets_init", "your_init");) does not help.
I have tried:
$post_id = get_the_id();
// or
$post_id = $GLOBALS['post']->ID;
// or
global $wp_query;
$post_id = $wp_query->post->ID;
// or
global $post;
$post_id = $post->ID;
All return some page ID, not the current post ID.
Here is my post link http://ori.co.il/roofdagan1/?p=1492
My widget code:
<?php
/*
Plugin Name: custom-post-field
Description: custom-post-field
*/
// Creating the widget
class cpf_widget extends WP_Widget
{
function __construct()
{
parent::__construct(
// Base ID of your widget
'cpf_widget',
// Widget name will appear in UI
__('CPF Widget', 'cpf_widget_domain'),
// Widget description
array( 'description' => __( 'Custom Post Field Widget', 'cpf_widget_domain' ), )
);
}
// Creating widget front-end
// This is where the action happens
public function widget( $args, $instance )
{
$title = apply_filters( 'widget_title', $instance['title'] );
// before and after widget arguments are defined by themes
echo $args['before_widget'];
if ( ! empty( $title ) )
echo $args['before_title'] . $title . $args['after_title'];
$post_id = $GLOBALS['post']->ID;
$resoult_ = "Post Id : ". $post_id;
// This is where you run the code and display the output
echo __( $resoult_, 'cpf_widget_domain' );
echo $args['after_widget'];
}
// Widget Backend
public function form( $instance )
{
if ( isset( $instance[ 'title' ] ) )
{
$title = $instance[ 'title' ];
}
else
{
$title = __( 'New title', 'cpf_widget_domain' );
}
// Widget admin form
?>
<p>
<label for="<?php echo $this->get_field_id( 'title' ); ?>"><?php _e( 'Title:' ); ?></label>
<input class="widefat" id="<?php echo $this->get_field_id( 'title' ); ?>" name="<?php echo $this->get_field_name( 'title' ); ?>" type="text" value="<?php echo esc_attr( $title ); ?>" />
</p>
<?php
}
// Updating widget replacing old instances with new
public function update( $new_instance, $old_instance )
{
$instance = array();
$instance['title'] = ( ! empty( $new_instance['title'] ) ) ? strip_tags( $new_instance['title'] ) : '';
return $instance;
}
} // Class cpf_widget ends here
// Register and load the widget
function cpf_load_widget()
{
register_widget( 'cpf_widget' );
}
add_action( 'widgets_init', 'cpf_load_widget' );
?>

Answer 1

You can use get_queried_object() to retrieve the currently-queried object:
$current_post = get_queried_object();
$post_id = $current_post ? $current_post->ID : null;