PHP计算字符串宽度（PX）------- imagettftext

// Set the content-type
header('Content-Type: image/png');


// Create the image
$im = imagecreatetruecolor(400, 30);


// Create some colors
$white = imagecolorallocate($im, 255, 255, 255);
$grey = imagecolorallocate($im, 128, 128, 128);
$black = imagecolorallocate($im, 0, 0, 0);
imagefilledrectangle($im, 0, 0, 399, 29, $white);


// The text to draw
$text = 'Testing...';
// Replace path by your own font path
$font = 'simhei.ttf';


// Add some shadow to the text
imagettftext($im, 20, 0, 11, 21, $grey, $font, $text);


// Add the text
imagettftext($im, 20, 0, 20, 20, $black, $font, $text);


// Using imagepng() results in clearer text compared with imagejpeg()
imagepng($im);
imagedestroy($im);
?>