wordpress如何在后台添加用户时添加自定义字段，下面模板兔给出相关代码：

function userMetaBirthdayForm(WP_User $user) {
?>
<h2>Birthday</h2>
<table class="form-table">
<tr>
<th><label for="user_birthday">Birthday</label></th>
<td>
<input
type="date"
value="<?php echo esc_attr(get_user_meta($user->ID, 'birthday', true)); ?>"
name="user_birthday"
id="user_birthday"
>
<span class="description">Some description to the input</span>
</td>
</tr>
</table>
<?php
}
add_action('show_user_profile', 'userMetaBirthdayForm'); // editing your own profile
add_action('edit_user_profile', 'userMetaBirthdayForm'); // editing another user
add_action('user_new_form', 'userMetaBirthdayForm'); // creating a new user
function userMetaBirthdaySave($userId) {
if (!current_user_can('edit_user', $userId)) {
return;
}
update_user_meta($userId, 'birthday', $_REQUEST['user_birthday']);
}
add_action('personal_options_update', 'userMetaBirthdaySave');
add_action('edit_user_profile_update', 'userMetaBirthdaySave');
add_action('user_register', 'userMetaBirthdaySave');

以上是添加用户、编辑用户、个人资料更新时都有效。