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为什么无法输出一张图片

时间：2021-07-01 10:21:17 帮助过：1人阅读

	session_start();		//随机码的个数	//$_rnd_code = 4;		//创建随机码	for($i=0;$i<4;$i++){		$_nmsg.=dechex(mt_rand(0,15));	}		//保存session	$_SESSION['code']=$_nmsg;		//长和高	$_width = 75;	$_height = 25;		//创建一张图像	$_img = imagecreatetruecolor($_width,$_height);		//

输出图像 header('Content-Type:image/png'); imagepng($_img);
输出结果为

回复讨论(解决方案)

$_nmsg='';
for($i=0;$i<4;$i++){
$_nmsg.=dechex(mt_rand(0,15));
}

	session_start();		//随机码的个数	//$_rnd_code = 4;		$_nmsg=' ';	//创建随机码	for($i=0;$i<4;$i++){		$_nmsg.=dechex(mt_rand(0,15));	}		//保存session	$_SESSION['code']=$_nmsg;		//长和高	$_width = 75;	$_height = 25;		//创建一张图像	$_img = imagecreatetruecolor($_width,$_height);		//白色	$_white = imagecolorallocate($_img,255,255,255);		//填充	imagefill($_img,0,0,$_white);		$_flag = false;		if($_flag){	//黑色边框	$_black = imagecolorallocate($_img,0,0,0);	imagerectangle($_img,0,0,$_width-1,$_height-1,$_black);	}		//随机画出6个线条	for($i=0;$i<6;$i++){		$_rnd_color = imagecolorallocate($_img,mt_rand(0,255),mt_rand(0,255),mt_rand(0,255));		imageline($_img,mt_rand(0,$_width),mt_rand(0,$_height),mt_rand(0,$_width),mt_rand(0,$_height),$_rnd_color);			}		//随机雪花	for($i=0;$i<100;$i++){		$_rnd_color = imagecolorallocate($_img,mt_rand(200,255),mt_rand(200,255),mt_rand(200,255));		imagestring($_img,1,mt_rand(1,$_width),mt_rand(1,$_height),'*',$_rnd_color);	}		//

输出验证码 for($i=0;$i输出图像 header('Content-Type:image/png'); imagepng($_img);
写完之后，还是显示


Notice:  Undefined variable: _rnd_code in D:\AMP\web\ide_tmp.php on line 53

Warning:  Division by zero in D:\AMP\web\ide_tmp.php on line 53

Notice:  Undefined variable: _heght in D:\AMP\web\ide_tmp.php on line 53

Warning:  mt_rand(): max(0) is smaller than min(1) in D:\AMP\web\ide_tmp.php on line 53

Notice:  Undefined variable: _rnd_code in D:\AMP\web\ide_tmp.php on line 53

Warning:  Division by zero in D:\AMP\web\ide_tmp.php on line 53

Notice:  Undefined variable: _heght in D:\AMP\web\ide_tmp.php on line 53

Warning:  mt_rand(): max(0) is smaller than min(1) in D:\AMP\web\ide_tmp.php on line 53

Notice:  Undefined variable: _rnd_code in D:\AMP\web\ide_tmp.php on line 53

Warning:  Division by zero in D:\AMP\web\ide_tmp.php on line 53

Notice:  Undefined variable: _heght in D:\AMP\web\ide_tmp.php on line 53

Warning:  mt_rand(): max(0) is smaller than min(1) in D:\AMP\web\ide_tmp.php on line 53

Notice:  Undefined variable: _rnd_code in D:\AMP\web\ide_tmp.php on line 53

Warning:  Division by zero in D:\AMP\web\ide_tmp.php on line 53

Notice:  Undefined variable: _heght in D:\AMP\web\ide_tmp.php on line 53

Warning:  mt_rand(): max(0) is smaller than min(1) in D:\AMP\web\ide_tmp.php on line 53

Notice:  Undefined variable: _rnd_code in D:\AMP\web\ide_tmp.php on line 53

Warning:  Division by zero in D:\AMP\web\ide_tmp.php on line 53

Notice:  Undefined variable: _heght in D:\AMP\web\ide_tmp.php on line 53

Warning:  mt_rand(): max(0) is smaller than min(1) in D:\AMP\web\ide_tmp.php on line 53
‰PNG

按错误信息修改
然后得：
仍然是不友好的“验证码”图片

将header注释掉，打开错误就可以看到错误。

为什么无法输出一张图片

回复讨论(解决方案)

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