Question

我想使用fpdf将mysql数据库转换为pdf，但是当我尝试从不同的文件调用函数从数据库中获取数据时，我总是失败，我已阅读了几篇类似问题的文章，但我仍然有一个错误消息，这是我的代码：

database.php中

    <?php
            class Database{

          private static $INSTANCE = null;
          private $mysqli,
                  $HOST = 'localhost',
                  $USER = 'root',
                  $PASS = '',
                  $DBNAME = 'newproject';

          public function __construct()
          {
            $this->mysqli = new mysqli( $this->HOST, $this->USER, $this->PASS, $this->DBNAME );
            if( mysqli_connect_error() ){
              die('Failed to connect');
            }
          }

          public static function getInstance()
          {
            if( !isset( self::$INSTANCE ) ){
              self::$INSTANCE = new Database();
            }

            return self::$INSTANCE;
          }

  public function get_info($table, $column = '', $value = '')
  {
    if( !is_int($value) )
      $value = "'". $value . "'";

      if( $column != '' ) {
        $query  = "SELECT * FROM $table WHERE $column = $value";
        $result = $this->mysqli->query($query);

        while($row = $result->fetch_assoc()){
           return $row;
        }
      }else{
        $query  = "SELECT * FROM $table";
        $result = $this->mysqli->query($query);

        while($row = $result->fetch_assoc()){
           $results[] = $row;
        }

        return $results;
      }
  }
    ?>

核心文件夹中的load.php

<?php

session_start();

spl_autoload_register(function($class){
  require_once 'classes/' .$class. '.php';
});

$user = new User();
?>

User.php

   <?php

    class User{

      private $_db;

      public function __construct()
      {
        $this->_db = Database::getInstance();
      }

public function get_asets()
  {
    return $this->_db->get_info('asets');
  }
?>

这是我的pdf转换器代码

<?php
require_once 'core/load.php';
require_once 'report/fpdf.php';

class PrintAset extends FPDF
{

      private $asets;

      function __construct(){
        $this->$asets = $user->get_asets();
      }

      function viewTable(){
        $this->SetFont('Times','',8);

        foreach ($asets as $aset) {
        $this->MultiCell(25,10,$aset['data1'],1,'C');
        $this->MultiCell(25,10,$aset['data2'],1,'C');
        $this->MultiCell(25,10,$aset['data3'],1,'C');
        $this->MultiCell(35,10,$aset['data4'],1,'C');
        $this->MultiCell(35,10,$aset['data5'],1,'C');
        $this->MultiCell(25,10,$aset['data6'],1,'C');
        $this->MultiCell(35,10,$aset['data7'],1,'C');
        }
       }
}

$pdf = new PrintAset();
$pdf->AliasNbPages();
$pdf->AddPage('L','A4','0');
$pdf->headerTable();
$pdf->viewTable();
$pdf->Output();

 ?>

当我在浏览器上测试时，这是返回的错误

注意：未定义的变量：用户输入   第11行的C：\ xampp \ htdocs_sikp \ cetakAset.php

致命错误：未捕获错误：调用成员函数get_asets（）   C：\ xampp \ htdocs_sikp \ cetakAset.php中的null：11堆栈跟踪：＃0   C：\ xampp \ htdocs_sikp \ cetakAset.php（53）：CetakAset-＆gt; __ construct（）＃1   {main}在第11行的C：\ xampp \ htdocs_sikp \ cetakAset.php中抛出

PHP无法在另一个类和文件的函数中使用函数

0 个答案: