php - 如何在分页 CodeIgniter 函数中使用参数？

Question

我有一个函数，它将州名称作为参数并显示该特定州的所有城市。由于城市列表很长，我在同一个函数中使用了分页，但是当我单击“下一步”或任何其他分页链接时，该函数接受 $state 变量中的偏移值。函数是

public function load_Page($state){
    $this->load->database();
    $this->load->library('pagination');
    $a = 1;

    $this->db->select("*")->where("userstate" , $a)->where("state" , $state);
    $query0 = $this->db->get("city");

            $this->db->select("*")->where("userstate" , $a)->where("state" , $state);
            $query1 = $this->db->get('city' , 10 , $this->uri->segment(3));
            $config["base_url"] = base_url()."index.php/city/load_Page";
            $total_row = $query0->num_rows();
            $config['page_query_string'] = TRUE;
            $config["total_rows"] = $total_row;
            $config["per_page"] = 10;

            $this->pagination->initialize($config);


            $data["state"] = $state;
            $data["result"] = $query1->result();
            //$data["rows"] = $query1->num_rows();
            $this->load->view('header');
            $this->load->view('city', $data);
            $this->load->view('footer');

}

还有其他办法吗？还是我完全错了？

Answer 1

首先，当您进行分页时，页码必须来自 URL，并且它始终作为 Controller 方法中的参数提供。它应该默认为第 1 页。

<?php
defined('BASEPATH') OR exit('No direct script access allowed');

class City extends CI_Controller {

    public function load_page( $state, $page = 1 ){

        // I'm going to use an alias for this model
        $this->load->model('example_model', 'model');

        // Use the URL helper for site_url()
        $this->load->helper('url');

        // Set pagination config
        $config['pagination_settings'] = [
            'per_page'          => 10,
            'use_page_numbers'  => TRUE,
            'uri_segment'       => 4, // This is very important!!!
            'base_url'          => site_url('city/load_page/' . $state)
        ];

        // Get the total rows
        $config['pagination_settings']["total_rows"] = $this->model->pagination_count( $state );

        // Load and initialize pagination
        $this->load->library('pagination');
        $this->pagination->initialize($config['pagination_settings']);

        $data = [
            'state' => $state,
            'rows' => $this->model->get_cities( $state, $page, $config['pagination_settings']['per_page'] ),
            'links' => $this->pagination->create_links()
        ];

        // Use data in views or wherever needed ...
        $this->load->view('city', $data);
    }

    /**
     * Create the rows to paginate
     */
    public function setup()
    {
        // I'm going to use an alias for this model
        $this->load->model('example_model', 'model');

        $this->model->setup();
    }

    // -----------------------------------------------------------------------
}

接下来，您应该将数据库查询移动到模型中。您不需要为 2 个选择类型查询使用事务。

<?php
defined('BASEPATH') or exit('No direct script access allowed');

class Example_model extends CI_Model{

    public function __construct()
    {
        parent::__construct();

        $this->load->database();
    }

    public function pagination_count( $state )
    {
        return $this->db->where("state" , $state)
            ->count_all_results('city');
    }

    public function get_cities( $state, $page, $limit )
    {
        $offset = ( $page * $limit ) - $limit;

        $query = $this->db->where("state" , $state)
            ->limit( $limit, $offset )
            ->get('city');

        if( $query->num_rows() > 0 )
            return $query->result();

        return NULL;
    }

    /**
     * Setup for testing
     */
    public function setup()
    {
        $this->load->dbforge();

        $fields = array(
            'id' => array(
                'type' => 'INT',
                'constraint' => 5,
                'unsigned' => TRUE,
                'auto_increment' => TRUE
            ),
            'state' => array(
                'type' => 'VARCHAR',
                'constraint' => '32',
            ),
            'city' => array(
                'type' => 'VARCHAR',
                'constraint' => '32',
            ),
        );
        $this->dbforge->add_field($fields);
        $this->dbforge->add_key('id', TRUE);
        $this->dbforge->create_table('city', TRUE);

        for( $x = 1; $x <= 40; $x++ )
        {
            $this->db->insert('city', array(
                'state' => 'ca',
                'city'  => 'x' . $x
            ));
        }
    }
}

这是我使用的 View :

<?php

echo '<h1>' . $state . '</h1>';

echo $links . '<br /><br />';

foreach( $rows as $row )
{
    echo $row->city . '<br />';
}

为了设置用于测试的数据库，我去了:

http://localhost/index.php/city/setup

然后为了检查分页是否有效，我去了:

http://localhost/index.php/city/load_page/ca

它应该对你有用，因为这段代码现在已经过全面测试。

更新--------------------

如果您想为分页添加更多参数，请使用查询字符串。您将需要使用此额外设置来设置分页配置:

$config['pagination_settings']['reuse_query_string'] = TRUE;

这意味着配置看起来像这样:

$config['pagination_settings'] = [
    'per_page'           => 10,
    'use_page_numbers'   => TRUE,
    'uri_segment'        => 4, // This is very important!!!
    'base_url'           => site_url('city/load_page/' . $state),
    'reuse_query_string' => TRUE
];

然后使用参数创建指向第一页的链接:

http://localhost/index.php/city/load_page/ca?a=1&b=2&c=3

并且由于 reuse_query_strings 被设置为 TRUE，这意味着 ?a=1&b=2&c=3 将全部附加到分页链接。