验证码在哪加时间的字符串才可以避免读缓存
这是我用类包装的一个验证图片功能 但是我不知道在哪加时间字符串才可以避免读缓存 还请高手指教下
<?phpclass ImageCode{ private $randcode; //随机字符 private $randcodelength; //随机字符长度 private $imgWidth; //随机字符宽度 private $imgHeight; //随机字符高度 private $line = 5; //干扰线 private $code = array("q","w","e","r","t","y","u","i","o","p","a","s","d","f","g","h","j","k","l","z","x","c","v","b","n","m", "Q","W","E","R","T","Y","U","I","O","P","A","S","D","F","G","H","J","K","L","Z","X","C","V","B","N","M", "1","2","3","4","5","6","7","8","9","0"); private $codelength; //数组的长度 private $image; //图片 private $background; //背景 private $foreground; //前景 function __construct(){ $this->randcodelength = 5; $this->imgWidth = 80; $this->imgHeight = 20; $this->codelength = count($this->code)-1; //获取数组长度当随机范围 $this->createrandcode(); $this->createimg(); $this->createString(); $this->drawline($this->line); $this->ending(); } function createrandcode(){ for($i=0;$i<$this->randcodelength;$i++){ //初始化验证码 $this->randcode .= $this->code[rand(0,$this->codelength)]; } } function createimg(){ //创建图片 前景 背景颜色 $this->image = imagecreatetruecolor($this->imgWidth,$this->imgHeight); $this->background = imagecolorallocate($this->image,0,0,0); $this->foreground = imagecolorallocate($this->image,255,255,255); } function createString(){ //创建字符串 imagestring($this->image,5,rand(5,35),0,$this->randcode,$this->foreground); } function drawline($some){ for($i=0;$i<$some;$i++){ imageline($this->image,rand(1,$this->imgWidth),rand(1,$this->imgHeight),rand(1,$this->imgWidth),rand(1,$this->imgHeight),$this->foreground); } } function ending(){ ob_clean(); //抛弃缓存内容 header("Content-type: image/jpeg"); imagejpeg($this->image); }}?>