PHP SLIM : 如何 return 动态生成图像

PHP SLIM : How to return dynamically generated images

我正在尝试显示从 SLIM 控制器动态生成的图像,但出现空白屏幕。 谢谢

public function textToImage($request, $response, $args) {

    // The text to draw
    $text = "Hello World";
    $length=strlen($text);
    // Create the image

    $im = imagecreatetruecolor($length*12, 30);

    // Create some colors
    $white = imagecolorallocate($im, 255, 255, 255);
    $grey = imagecolorallocate($im, 128, 128, 128);
    $black = imagecolorallocate($im, 44, 62, 80);
    $boxcolor=imagecolorallocate($im, 95, 128, 149);

    $font = 'Helvetica.ttf';
    imagefilledrectangle($im, 0, 0, $length*9+$capitaladjust, 29, $white);
    imagettftext($im, 13, 0, 0, 20, $black, $font, $text);

    $response->getBody()->write(base64_encode($im));
    $response = $response->withHeader('Content-type', 'image/png');     
    return $response;
 }

base64 编码 $im 不会创建有效的 PNG 文件。尝试使用 imgpng,然后发送它创建的 PNG 文件的原始内容。

代码看起来像这样:

ob_start();
imagepng($im);
$data = ob_get_contents();
ob_end_clean();

$response->getBody()->write($data);
$response = $response->withHeader('Content-type', 'image/png');     
return $response;