无法使用下面的文本创建QR

Question

我使用此代码制作具有以下自定义文本的qr代码。我尝试了几种方法，但我总是失败。我需要帮助。

// Set the content-type 
header('Content-Type: image/png'); 
header("Content-Disposition: filename='sample.png'"); 
$main = imagecreatetruecolor(150, 180); 
$qr = imagecreatefrompng("https://api.qrserver.com/v1/create-qr-code/?size=150x150&format=png&margin=5&data=sample"); 
// Create the image 
$im = imagecreatetruecolor(150, 30); 
// Create some colors 
$black = imagecolorallocate($im, 255, 255, 255); 
imagefilledrectangle($im, 0, 0, 399, 29, $black); 
// Font path 
$font = 'arial.ttf'; 
// Add the text 
imagettftext($im, 20, 0, 5, 25, $black, $font, 'sample'); 
imagecopymerge_alpha($main, $qr, 0, 0, 0, 0, 150, 150, 100); 
imagecopymerge_alpha($main, $im, 0, 150, 0, 0, 150, 30, 100); 
imagepng($main); 
imagedestroy($main); 

而我只是看到空白页。

Answer 1

你有一个错误，但你不能在浏览器中查看它，因为你已经设置了Content-Type: image/png这样的调试只是注释掉该行或检查你的服务器日志。

我想起的第一件事是this answer使用相对于您的字体的路径。这足以引发一个警告，即如果输出到屏幕会让您的图像变得模糊不已，更不用说您不会获得所需的字体。我会fix this line。

$font = realpath(__DIR__.'/arial.ttf'); 

对我来说，致命的错误是：

调用未定义功能imagecopymerge_alpha（）

我不知道你在哪里得到的代码，但是我发现这样this question我认为它可能是相关的。

function imagecopymerge_alpha($dst_im, $src_im, $dst_x, $dst_y, $src_x, $src_y, $src_w, $src_h, $pct){ 
    // creating a cut resource 
    $cut = imagecreatetruecolor($src_w, $src_h); 

    // copying relevant section from background to the cut resource 
    imagecopy($cut, $dst_im, 0, 0, $dst_x, $dst_y, $src_w, $src_h); 

    // copying relevant section from watermark to the cut resource 
    imagecopy($cut, $src_im, 0, 0, $src_x, $src_y, $src_w, $src_h); 

    // insert cut resource to destination image 
    imagecopymerge($dst_im, $cut, $dst_x, $dst_y, 0, 0, $src_w, $src_h, $pct); 
} 

然后我注意到了白色标记为黑色，并设置为两个背景和文本颜色 - 因此，无论哪种颜色的它，那将是不可见的。所以我changed these lines。 （-意味着删除线和+手段添加的行。）

// Create the image 
$im = imagecreatetruecolor(150, 30); 
// Create some colors 
-$black = imagecolorallocate($im, 255, 255, 255); 
+$white = imagecolorallocate($im, 255, 255, 255); 
+$black = imagecolorallocate($im, 0, 0, 0); 
imagefilledrectangle($im, 0, 0, 399, 29, $black); 
// Font path 
$font = realpath(__DIR__.'/arial.ttf'); 
// Add the text 
-imagettftext($im, 20, 0, 5, 25, $black, $font, 'sample'); 
+imagettftext($im, 20, 0, 5, 25, $white, $font, 'sample'); 
imagecopymerge_alpha($main, $qr, 0, 0, 0, 0, 150, 150, 100); 
imagecopymerge_alpha($main, $im, 0, 150, 0, 0, 150, 30, 100); 
imagepng($main); 

最后，而不是硬编码字sample，只是为了好玩我设置的查询字符串。

+$text = $_GET['qr'] ?? 'sample'; 
+ 
// Set the content-type 
header('Content-Type: image/png'); 
header("Content-Disposition: filename='sample.png'"); 
$main = imagecreatetruecolor(150, 180); 
-$qr = imagecreatefrompng("https://api.qrserver.com/v1/create-qr-code/?size=150x150&format=png&margin=5&data=sample"); 
+$qr = imagecreatefrompng("https://api.qrserver.com/v1/create-qr-code/?size=150x150&format=png&margin=5&data=$text"); 
// Create the image 
$im = imagecreatetruecolor(150, 30); 
// Create some colors 
@@ -14,7 +16,7 @@ imagefilledrectangle($im, 0, 0, 399, 29, $black); 
// Font path 
$font = realpath(__DIR__.'/arial.ttf'); 
// Add the text 
-imagettftext($im, 20, 0, 5, 25, $white, $font, 'sample'); 
+imagettftext($im, 20, 0, 5, 25, $white, $font, $text); 

GET/

GET /？QR =你好

<?php 

$text = $_GET['qr'] ?? 'sample'; 

// Set the content-type 
header('Content-Type: image/png'); 
header("Content-Disposition: filename='sample.png'"); 
$main = imagecreatetruecolor(150, 180); 
$qr = imagecreatefrompng("https://api.qrserver.com/v1/create-qr-code/?size=150x150&format=png&margin=5&data=$text"); 
// Create the image 
$im = imagecreatetruecolor(150, 30); 
// Create some colors 
$white = imagecolorallocate($im, 255, 255, 255); 
$black = imagecolorallocate($im, 0, 0, 0); 
imagefilledrectangle($im, 0, 0, 399, 29, $black); 
// Font path 
$font = realpath(__DIR__.'/arial.ttf'); 
// Add the text 
imagettftext($im, 20, 0, 5, 25, $white, $font, $text); 
imagecopymerge_alpha($main, $qr, 0, 0, 0, 0, 150, 150, 100); 
imagecopymerge_alpha($main, $im, 0, 150, 0, 0, 150, 30, 100); 
imagepng($main); 
imagedestroy($main); 

function imagecopymerge_alpha($dst_im, $src_im, $dst_x, $dst_y, $src_x, $src_y, $src_w, $src_h, $pct){ 
    // creating a cut resource 
    $cut = imagecreatetruecolor($src_w, $src_h); 

    // copying relevant section from background to the cut resource 
    imagecopy($cut, $dst_im, 0, 0, $dst_x, $dst_y, $src_w, $src_h); 

    // copying relevant section from watermark to the cut resource 
    imagecopy($cut, $src_im, 0, 0, $src_x, $src_y, $src_w, $src_h); 

    // insert cut resource to destination image 
    imagecopymerge($dst_im, $cut, $dst_x, $dst_y, 0, 0, $src_w, $src_h, $pct); 
}