Michael Fields

I got this link from Rarst via Twitter, it’s probably what you want to try:

http://codex.ww.wp.xz.cn/Function_Reference/the_widget

If you really do not need the widget, check out this function:

http://codex.ww.wp.xz.cn/Function_Reference/get_the_term_list

Somewhere in your theme after the script where jgdDropdown() is defined.

and is it possible to display the drop down for posts???
means all my posts will come in drop-down??

No. The dropdown will only display terms of the taxonomy that you choose when you install the widget.

I don’t really like to use shortcodes in Widgets. I don’t think that WordPress supports this out-of-the-box. I know there are ways to get around this, but I do not personally use them. You may want to start a new thread about that topic.

If you add the following code to the code I posted above, you will have a really simple widget that only displays on single post views:

class My_Themes_Taxonomy_Term_Widget extends WP_Widget {
	function My_Themes_Taxonomy_Term_Widget() {
		$widget = array(
			'class' => 'My_Themes_Taxonomy_Term_Widget',
			'description' => ''
			);
		$this->WP_Widget( 'My_Themes_Taxonomy_Term_Widget', 'My Themes Taxonomy Term Widget', $widget );
	}
	function widget( $args, $instance ) {
		if ( is_single() ) {
			mfields_list_terms( $taxonomy = 'topics' );
		}
	}
}

function register_my_themes_taxonomy_term_widget() {
	register_widget( 'My_Themes_Taxonomy_Term_Widget' );
}

add_action( 'widgets_init', 'register_my_themes_taxonomy_term_widget' );

I use something like this in my site’s redesign feel free to use it. It’s not a widget though:

Add to functions.php

/*
 * Must be used inside loop.
 * @since 2010-12-05
 */
function mfields_list_terms( $taxonomy = 'category', $labels = array() ) {
	global $post;
	$labels = array_merge( array(
		'singular' => 'Category',
		'plural'   => 'Categories',
		'override' => ''
		), $labels );
	if ( is_object_in_taxonomy( $post->post_type, $taxonomy ) ) {
		$terms = get_the_terms( $post->ID, $taxonomy );
		if ( ! is_wp_error( $terms ) && is_array( $terms ) ) {
			$label = $labels['plural'];
			if ( !empty( $labels['override'] ) ) {
				$label = $labels['override'];
			}
			else if ( 1 === count( $terms ) ) {
				$label = $labels['singular'];
			}
			print "\n" . '<h2>' . $label . '</h2>';
			print "\n" . '<ul>';
			foreach( (array) $terms as $term ) {
				$href = get_term_link( $term, $taxonomy );
				if ( ! is_wp_error( $href ) && isset( $term->name ) ) {
					print "\n" . '<li><a href="' . esc_url( $href ) . '">' . $term->name . '</a></li>';
				}
			}
			print "\n" . '</ul>';
		}
	}
}

Add to template file:

mfields_list_terms( 'topics', array(
	'singular' => 'Topic',
	'plural' => 'Topics'
	) );

Thanks. Not sure I completely understand the trouble you are having though… Do you have a link?