Question

我正在使用TCPDF制作奖励生成器。它会检查奖励的类型，并根据它填写image_path变量（以及与此问题无关的其他一些变量。

switch($award){
    case 25:
        $img_file = '../../img/award_25.png';
        break;
    case 50:
        $img_file = '../../img/award_50.png';
        break;
    ... and so on ...
}

再远一点，如TCPDF的example_051所示，它们扩展了类以定义背景图像。该图像的路径是上面创建的变量$ img_file中的路径。

require_once('tcpdf_include.php');
class MYPDF extends TCPDF {
    public function Header() {
        // get the current page break margin
        $bMargin = $this->getBreakMargin();
        // get current auto-page-break mode
        $auto_page_break = $this->AutoPageBreak;
        // disable auto-page-break
        $this->SetAutoPageBreak(false, 0);
        // margins Left, Top, Right, Bottom in pixels
        $this->Image($img_file, -9, -8, 316, 225, '', '', '', false, 300, '', false, false, 0);
        // restore auto-page-break status
        $this->SetAutoPageBreak($auto_page_break, $bMargin);
        // set the starting point for the page content
        $this->setPageMark();
    }
}

由于范围，变量$ image_file在扩展中是未知的。有没有办法让这项工作成功？

提前致谢！

Answer 1

class MYPDF extends TCPDF {
protected $img_file;
 public function __construct($img_file)
    {
        $this->img_file = $img_file;
    }
    public function Header() {
        // get the current page break margin
        $bMargin = $this->getBreakMargin();
        // get current auto-page-break mode
        $auto_page_break = $this->AutoPageBreak;
        // disable auto-page-break
        $this->SetAutoPageBreak(false, 0);
        // margins Left, Top, Right, Bottom in pixels
        $this->Image($img_file, -9, -8, 316, 225, '', '', '', false, 300, '', false, false, 0);
        // restore auto-page-break status
        $this->SetAutoPageBreak($auto_page_break, $bMargin);
        // set the starting point for the page content
        $this->setPageMark();
    }
}
$MYPDF = new MYPDF($img_file);

Answer 2

查看$GLOBALS个变量这是一个例子

<?php
$a = 1;
$b = 2;

function Sum()
{
    $GLOBALS['b'] = $GLOBALS['a'] + $GLOBALS['b'];
} 

Sum();
echo $b;
?>

有关变量范围的更多信息here

Answer 3

您需要将变量$ img_file设为全局，以便在函数内部使用。这需要在函数内部完成手册在这里： http://php.net/manual/en/language.variables.scope.php

public function Header() {
    global $img_file;
    // get the current page break margin
    $bMargin = $this->getBreakMargin();

    ...

Answer 4

这对我有用。

class MYPDF extends TCPDF {
  private $data = array();

  public function setData($key, $value) {
    $this->data[$key] = $value;
  }

  public function Header() {
    $this->data['invoice_no'];
    .... 
  }
}    
$pdf = new MYPDF(PDF_PAGE_ORIENTATION, PDF_UNIT, PDF_PAGE_FORMAT, true, 'UTF-8', false); 
$pdf->setData('invoice_no', $invoice_no);

PHP在扩展类中使用外部变量

4 个答案: