网上查了一下

$background = imagecolorallocate($this->img, hexdec(substr($this->background, 1, 2)), hexdec(substr($this->background, 3, 2)), hexdec(substr($this->background, 5, 2)))

换成了

$background = imagecolorallocatealpha($this->img, 255, 255, 255, 127);

结果验证码背景色变成了纯黑色，请问大家应该怎么改

附件已上传，最好帮我改好发过来，谢谢！

Captcha.zip