How do you set only the image width of a Wordpress thumbnail

Question

I am trying to set the width of a post thumbnail using:

the_post_thumbnail()

The width of the image needs to be 210px but the height is not meant to be fixed as all the images will be different sizes. I have tried:

the_post_thumbnail( array( 210, 0 ) ) 

But this does not work. Any ideas?

Thanks.

Answer 1

Add this inside your functions.php

if ( function_exists( 'add_image_size' ) ) { 
    add_image_size( 'category-thumb', 210, 9999 ); //210 pixels wide (and unlimited height)

}

Use it inside your theme's template files

<?php if ( has_post_thumbnail() ) { the_post_thumbnail( 'category-thumb' ); } ?>

For default thumbnail add this inside your functions.php

if ( function_exists( 'add_theme_support' ) ) {
    add_theme_support( 'post-thumbnails' );
    set_post_thumbnail_size( 150, 9999 ); // default Post Thumbnail dimensions   
}

Reference: Here.