Wordpress - How to redirect to settings page once the plugin is activated?

Maybe using the wp_redirect() function in the activation hook. In the following example myplugin_settings is a placeholder. Normally this simply is the $hook_suffix you get back from $hook_suffix = add_menu_page( /* etc. */ ); and similar functions.

THIS CODE DOESN'T WORK, READ BELOW

register_activation_hook(__FILE__, 'cyb_activation');
function cyb_activation()
{
    // Don't forget to exit() because wp_redirect doesn't exit automatically
    exit( wp_redirect( admin_url( 'options-general.php?page=myplugin_settings' ) ) );
}

References:

1. Register activation hook
2. admin_url()

EDIT

The redirect inside the activation hook seems to be performed before the plugin is effectively activated, maybe because of the call of exit() before the activation is executed. This code seems to work well using activated_plugin action hook:

function cyb_activation_redirect( $plugin ) {
    if( $plugin == plugin_basename( __FILE__ ) ) {
        exit( wp_redirect( admin_url( 'options-general.php?page=myplugin_settings' ) ) );
    }
}
add_action( 'activated_plugin', 'cyb_activation_redirect' );

If you use this code outside the main plugin file you will need to replace __FILE__ with path of the main plugin file.

THOUGHT

Redirecting the user after your plugin has been activated is not a very good approach. In Wordpress you can activate plugins in bulk. What happen then if you perform a redirect in this situation? You will break the activation of some plugins, maybe not if your plugin is the last being activated, but definitely you are breaking the user experience.

You should be able to do it like this:

register_activation_hook(__FILE__, 'my_plugin_activate');
add_action('admin_init', 'my_plugin_redirect');

function my_plugin_activate() {
    add_option('my_plugin_do_activation_redirect', true);
}
// Solution 1
function my_plugin_redirect() {
    if (get_option('my_plugin_do_activation_redirect', false)) {
        delete_option('my_plugin_do_activation_redirect');
         wp_redirect("options-general.php?page=rotator");
         //wp_redirect() does not exit automatically and should almost always be followed by exit.
         exit;
    }
}

// OR

//Solution 2 (@kaiser suggestion)
function my_plugin_redirect() {
    if (get_option('my_plugin_do_activation_redirect', false)) {
        delete_option('my_plugin_do_activation_redirect');
         exit( wp_redirect("options-general.php?page=rotator") );
    }
}

UPDATE

Even if it's a inline comment, remember:

wp_redirect() does not exit automatically and should almost always be followed by exit.

Specific example

<?php
    wp_redirect( $location, $status );
    exit;
?>

UPDATE 10/29/2013

It was not mentioned, but please note that my solution offers the ability to check if is the case or not to do a redirect to plugin settings page. Check my_plugin_activate and the if condition in my_plugin_redirect.

Hope it helps!

Hello i have used bellows code redirect after plugin activation. You can use this code. It's working nicely.

register_activation_hook(__FILE__, 'nht_plugin_activate');
add_action('admin_init', 'nht_plugin_redirect');

function nht_plugin_activate() {
add_option('nht_plugin_do_activation_redirect', true);
}

function nht_plugin_redirect() {
if (get_option('nht_plugin_do_activation_redirect', false)) {
    delete_option('nht_plugin_do_activation_redirect');
    if(!isset($_GET['activate-multi']))
    {
        wp_redirect("edit.php?post_type=headline&page=news-headline");
    }
 }
}