我将此函数用作插件，但您也可以在函数中使用它。php。

但我仍然没有找到添加用户角色的方法，我像文本框一样使用它，但我们也可以在select中使用它，但我不知道它是否正常工作，如果不正确，我希望有人可以添加它。

<?php

/*
  Plugin Name: Registration Form
  Description: Custom sign up form.
  Version: 1.1
  Author: Me
 */



/////////////////
// PLUGIN CORE //
/////////////////

function cr(&$fields, &$errors) {

  // Check args and replace if necessary
  if (!is_array($fields))     $fields = array();
  if (!is_wp_error($errors))  $errors = new WP_Error;

  // Check for form submit
  if (isset($_POST[\'submit\'])) {

    // Get fields from submitted form
    $fields = cr_get_fields();

    // Validate fields and produce errors
    if (cr_validate($fields, $errors)) {

      // If successful, register user
      wp_insert_user($fields);

      // And display a message
      echo \'Registration complete. Goto <a href="\' . get_site_url() . \'/wp-login.php">login page</a>.\';

      // Clear field data
      $fields = array(); 
    }
  }

  // Santitize fields
  cr_sanitize($fields);

  // Generate form
  cr_display_form($fields, $errors);
}

function cr_sanitize(&$fields) {
  $fields[\'user_login\']   =  isset($fields[\'user_login\'])  ? sanitize_user($fields[\'user_login\']) : \'\';
  $fields[\'user_pass\']    =  isset($fields[\'user_pass\'])   ? esc_attr($fields[\'user_pass\']) : \'\';
  $fields[\'user_email\']   =  isset($fields[\'user_email\'])  ? sanitize_email($fields[\'user_email\']) : \'\';
  $fields[\'user_url\']     =  isset($fields[\'user_url\'])    ? esc_url($fields[\'user_url\']) : \'\';
  $fields[\'first_name\']   =  isset($fields[\'first_name\'])  ? sanitize_text_field($fields[\'first_name\']) : \'\';
  $fields[\'last_name\']    =  isset($fields[\'last_name\'])   ? sanitize_text_field($fields[\'last_name\']) : \'\';
  $fields[\'nickname\']     =  isset($fields[\'nickname\'])    ? sanitize_text_field($fields[\'nickname\']) : \'\';
  $fields[\'description\']  =  isset($fields[\'description\']) ? esc_textarea($fields[\'description\']) : \'\';
  $fields[\'role\']  =  isset($fields[\'role\']) ? esc_textarea($fields[\'role\']) : \'\';
}

function cr_display_form($fields = array(), $errors = null) {

  // Check for wp error obj and see if it has any errors  
  if (is_wp_error($errors) && count($errors->get_error_messages()) > 0) {

    // Display errors
    ?><ul><?php
    foreach ($errors->get_error_messages() as $key => $val) {
      ?><li>
        <?php echo $val; ?>
      </li><?php
    }
    ?></ul><?php
  }

  // Disaply form

  ?><form action="<?php $_SERVER[\'REQUEST_URI\'] ?>" method="post">
    <div>
      <label for="user_login">Username <strong>*</strong></label>
      <input type="text" name="user_login" value="<?php echo (isset($fields[\'user_login\']) ? $fields[\'user_login\'] : \'\') ?>">
    </div>

    <div>
      <label for="user_pass">Password <strong>*</strong></label>
      <input type="password" name="user_pass">
    </div>

    <div>
      <label for="email">Email <strong>*</strong></label>
      <input type="text" name="user_email" value="<?php echo (isset($fields[\'user_email\']) ? $fields[\'user_email\'] : \'\') ?>">
    </div>

    <div>
      <label for="website">Website</label>
      <input type="text" name="user_url" value="<?php echo (isset($fields[\'user_url\']) ? $fields[\'user_url\'] : \'\') ?>">
    </div>

    <div>
      <label for="firstname">First Name</label>
      <input type="text" name="first_name" value="<?php echo (isset($fields[\'first_name\']) ? $fields[\'first_name\'] : \'\') ?>">
    </div>

    <div>
      <label for="website">Last Name</label>
      <input type="text" name="last_name" value="<?php echo (isset($fields[\'last_name\']) ? $fields[\'last_name\'] : \'\') ?>">
    </div>

    <div>
      <label for="role">Role : Author, Contributor, Editor and Subscriber</label>
      <input type="text" name="role" value="<?php echo (isset($fields[\'role\']) ? $fields[\'role\'] : \'\') ?>">
    </div>

    <div>
      <label for="nickname">Nickname</label>
      <input type="text" name="nickname" value="<?php echo (isset($fields[\'nickname\']) ? $fields[\'nickname\'] : \'\') ?>">
    </div>

    <div>
      <label for="bio">About / Bio</label>
      <textarea name="description"><?php echo (isset($fields[\'description\']) ? $fields[\'description\'] : \'\') ?></textarea>
    </div>

    <input type="submit" name="submit" value="Register">
    </form><?php
}

function cr_get_fields() {
  return array(
    \'user_login\'   =>  isset($_POST[\'user_login\'])   ?  $_POST[\'user_login\']   :  \'\',
    \'user_pass\'    =>  isset($_POST[\'user_pass\'])    ?  $_POST[\'user_pass\']    :  \'\',
    \'user_email\'   =>  isset($_POST[\'user_email\'])   ?  $_POST[\'user_email\']        :  \'\',
    \'user_url\'     =>  isset($_POST[\'user_url\'])     ?  $_POST[\'user_url\']     :  \'\',
    \'first_name\'   =>  isset($_POST[\'first_name\'])   ?  $_POST[\'first_name\']        :  \'\',
    \'last_name\'    =>  isset($_POST[\'last_name\'])    ?  $_POST[\'last_name\']        :  \'\',
    \'nickname\'     =>  isset($_POST[\'nickname\'])     ?  $_POST[\'nickname\']     :  \'\',
    \'description\'  =>  isset($_POST[\'description\'])  ?  $_POST[\'description\']  :  \'\',
    \'role\'  =>  isset($_POST[\'role\'])  ?  $_POST[\'role\']  :  \'\'
  );
}

function cr_validate(&$fields, &$errors) {

  // Make sure there is a proper wp error obj
  // If not, make one
  if (!is_wp_error($errors))  $errors = new WP_Error;

  // Validate form data

  if (empty($fields[\'user_login\']) || empty($fields[\'user_pass\']) || empty($fields[\'user_email\'])) {
    $errors->add(\'field\', \'Required form field is missing\');
  }

  if (strlen($fields[\'user_login\']) < 4) {
    $errors->add(\'username_length\', \'Username too short. At least 4 characters is required\');
  }

  if (username_exists($fields[\'user_login\']))
    $errors->add(\'user_name\', \'Sorry, that username already exists!\');

  if (!validate_username($fields[\'user_login\'])) {
    $errors->add(\'username_invalid\', \'Sorry, the username you entered is not valid\');
  }

  if (strlen($fields[\'user_pass\']) < 5) {
    $errors->add(\'user_pass\', \'Password length must be greater than 5\');
  }

  if (!is_email($fields[\'user_email\'])) {
    $errors->add(\'email_invalid\', \'Email is not valid\');
  }

  if (email_exists($fields[\'user_email\'])) {
    $errors->add(\'email\', \'Email Already in use\');
  }

  if (!empty($fields[\'user_url\'])) {
    if (!filter_var($fields[\'user_url\'], FILTER_VALIDATE_URL)) {
      $errors->add(\'user_url\', \'Website is not a valid URL\');
    }
  }

  // If errors were produced, fail
  if (count($errors->get_error_messages()) > 0) {
    return false;
  }

  // Else, success!
  return true;


}



///////////////
// SHORTCODE //
///////////////

// The callback function for the [cr] shortcode
function cr_cb() {
  $fields = array();
  $errors = new WP_Error();

  // Buffer output
  ob_start();

  // Custom registration, go!
  cr($fields, $errors);

  // Return buffer
  return ob_get_clean();
}
add_shortcode(\'cr\', \'cr_cb\');