do_action()

描述

This function invokes all functions attached to action hook $tag. It is possible to create new action hooks by simply calling this function, specifying the name of the new hook using the $tag parameter.

You can pass extra arguments to the hooks, much like you can with apply_filters().

Example usage:

// The action callback function.
function example_callback( $arg1, $arg2 ) {
 // (maybe) do something with the args.
}
add_action( 'example_action', 'example_callback', 10, 2 );
/*
 * Trigger the actions by calling the 'example_callback()' function
 * that's hooked>
参数
$tag
 (string)
 (Required)
 The name of the action to be executed. 
$arg
 (mixed)
 (Optional)
  Additional arguments which are passed on to the functions hooked to the action. Default empty.