#更新：哇，我觉得自己像个小丑。。。哈哈。WP_Role::has_cap

我的眼睛不够硬。

$caps  = array( \'cap_1\', \'cap_2\', \'cap_3\' );
$roles = array( \'administrator\', \'editor\' );

foreach( $roles as $role ) {
    if( $role_object = get_role( $role ) ) {
        foreach( $caps as $cap ) {
            if( !$role_object->has_cap( $cap ) ) {
                $role_object->add_cap( $cap );
            }
        }
    }
}

忽略这一点：很抱歉，我的另一个答案是每个用户，而不是每个角色。

您可以做的是检查角色是否具有使用get_role()

你可以看到get_role( \'administrator\' ) 将返回一个包含一系列功能的对象。

$administrator = get_role( \'administrator\' );

// Make sure role object was retrieved
if( $administrator ){
    //See if it\'s got our capability or not
    if( !in_array( \'my-custom-cap\', $administrator->capabilities ) ){
        // Wasn\'t there, so add it here
        $administrator->add_cap( \'my-custom-cap\' );
    }
}

如果出于某种原因，您不想运行$role 每次进行对象比较时，可以定义一次，然后在数据库中使用update_option() 并检查get_option()

if( get_option( \'manually_set_add_cap_admin\' ) != true ){
    $administrator = get_role( \'administrator\' );

    // Make sure role object was retrieved
    if( $administrator ){
        //See if it\'s got our capability or not
        if( !in_array( \'my-custom-cap\', $administrator->capabilities ) ){
            // Wasn\'t there, so add it here
            $administrator->add_cap( \'my-custom-cap\' );
            update_option( \'manually_set_add_cap_admin\', true );
        }
    }
}

这里有一个更冗长的解决方案，它将遍历您添加的任何角色，并为它们提供所有适当的功能。循环完成后，它将设置一个选中的标志，这样在第一次运行之后就不会有任何WP\\U角色对象获取。

// Define flag as a variable to prevent typos, in update/get_option
// or it will constantly run (I know from experience...)
$flag = \'manually_added_my_custom_caps\';

if( !get_option( $flag ) ){
    // Our flag option wasn\'t set, that means this code hasn\'t run yet.

    $roles        = array( \'administrator\', \'editor\' );
    $capabilities = array( \'custom-cap-1\', \'custom-cap-2\' );

    // Loop through each role
    foreach( $roles as $role ){
        // Make sure we got a WP_Role object back
        if( $role_object = get_role( $role ) ){
            // Loop through our custom capabilities
            foreach( $capabilities as $cap ){
                // Our option flag wasn\'t set, but let\'s confirm
                // that the role doesn\'t have the cap
                if( !in_array( $cap, $role_object->capabilities ) ){
                    // Confirmed not there, add it here
                    $role_object->add_cap( $cap );
                }
            }
        }
    }

    // Our function ran, it should have set all caps to all the roles
    // so now our code will skip this entirely next time
    update_option( $flag, true );
}