生成验证码图片，并输出;怎么输出的总是X的图片-PHP Tutorial-php.cn

生成验证码图片，并输出;怎么输出的总是X的图片

WBOY

Release： 2016-06-23 13:53:15

Original

1016 people have browsed it

   $num=" ";
   for($i=0;$i      $num .=rand(0,9);
   }
   session_start();
   $_SESSION["Checknum"]=$num;
   header("Content-type:image/png");
   srand((double)microtime()*1000000);
   $im=@imagecreate(60,20);
   @imagecolorallocate($im,255,255,255);
   $black=imagecolorallocate($im,0,0,0);
   $gray=imagecolorallocate($im,200,200,200);
   imagefill($im,0,0,$gray);
   $style=array($black,$black,$black,$black,$black,$gray,$gray,$gray,$gray,$gray);
   imagesetstyle($im,$style);
   $y1=rand(0,20);
   $y2=rand(0,20);
   $y3=rand(0,20);
   $y4=rand(0,20);
   imageline($im,0,$y1,60,$y3,IMG_COLOR_STYLED);
   imageline($im,0,$y2,60,$y4,IMG_COLOR_STYLED);
   for($i=0;$i      imagesetpixel($im,rand(0,60),rand(0,20),$black);
   }
   $strx=rand(3,8);
   for($i=0;$i      $strpos=rand(1,6);
imagestring($im,5,$strx,$strpos,substr($num,$i,1),$black);
$strx+=rand(8,12);
   }
   imagepng($im);
   imagedestroy($im);
?>

回复讨论(解决方案)

1、没有加载 GD 扩展
2、程序文件有 BOM 头

你看参考下这个：
http://blog.csdn.net/u011619326/article/details/37744855

去掉最上面的中文，session_start() 修改一下位置，似乎就可以了

session_start();
   $num=" ";
   for($i=0;$i      $num .=rand(0,9);
   }

   $_SESSION["Checknum"]=$num;
   header("Content-type:image/png");
   srand((double)microtime()*1000000);
   $im=@imagecreate(60,20);
   @imagecolorallocate($im,255,255,255);
   $black=imagecolorallocate($im,0,0,0);
   $gray=imagecolorallocate($im,200,200,200);
   imagefill($im,0,0,$gray);
   $style=array($black,$black,$black,$black,$black,$gray,$gray,$gray,$gray,$gray);
   imagesetstyle($im,$style);
   $y1=rand(0,20);
   $y2=rand(0,20);
   $y3=rand(0,20);
   $y4=rand(0,20);
   imageline($im,0,$y1,60,$y3,IMG_COLOR_STYLED);
   imageline($im,0,$y2,60,$y4,IMG_COLOR_STYLED);
   for($i=0;$i      imagesetpixel($im,rand(0,60),rand(0,20),$black);
   }
   $strx=rand(3,8);
   for($i=0;$i      $strpos=rand(1,6);
imagestring($im,5,$strx,$strpos,substr($num,$i,1),$black);
$strx+=rand(8,12);
   }
   imagepng($im);
   imagedestroy($im);
?>