如何用PHP生成GIF動(dòng)畫來實(shí)現(xiàn)動(dòng)態(tài)圖片驗(yàn)證碼？相信您要在找答案，以下是實(shí)現(xiàn)過程。

ImageCode函數(shù)通過GIFEncoder類實(shí)現(xiàn)的GIF動(dòng)畫的PHP源代碼，有興趣的朋友可以研究一下。

有關(guān)GIFEncoder類。 具體代碼入如下：

/**

* ImageCode 生成GIF圖片驗(yàn)證

* @param $string 字符串

* @param $width 寬度

* @param $height 高度

* */

function ImageCode($string = '', $width = 75, $height = 25)

{

$authstr = $string ? $string : ((time() % 2 == 0) ? mt_rand(1000, 9999) : mt_rand(10000, 99999));

$board_width = $width;

$board_height = $height;

// 生成一個(gè)32幀的GIF動(dòng)畫

for($i = 0; $i < 32; $i++)

{

ob_start();

$image = imagecreate($board_width, $board_height);

imagecolorallocate($image, 0,0,0);

// 設(shè)定文字顏色數(shù)組

$colorList[] = ImageColorAllocate($image, 15,73,210);

$colorList[] = ImageColorAllocate($image, 0,64,0);

$colorList[] = ImageColorAllocate($image, 0,0,64);

$colorList[] = ImageColorAllocate($image, 0,128,128);

$colorList[] = ImageColorAllocate($image, 27,52,47);

$colorList[] = ImageColorAllocate($image, 51,0,102);

$colorList[] = ImageColorAllocate($image, 0,0,145);

$colorList[] = ImageColorAllocate($image, 0,0,113);

$colorList[] = ImageColorAllocate($image, 0,51,51);

$colorList[] = ImageColorAllocate($image, 158,180,35);

$colorList[] = ImageColorAllocate($image, 59,59,59);

$colorList[] = ImageColorAllocate($image, 0,0,0);

$colorList[] = ImageColorAllocate($image, 1,128,180);

$colorList[] = ImageColorAllocate($image, 0,153,51);

$colorList[] = ImageColorAllocate($image, 60,131,1);

$colorList[] = ImageColorAllocate($image, 0,0,0);

$fontcolor = ImageColorAllocate($image, 0,0,0);

$gray = ImageColorAllocate($image, 245,245,245);

$color = imagecolorallocate($image, 255,255,255);

$color2 = imagecolorallocate($image, 255,0,0);

imagefill($image, 0, 0, $gray);

$space = 15; // 字符間距

if($i > 0) // 屏蔽第一幀

{

for ($k = 0; $k < strlen($authstr); $k++)

{

$colorRandom = mt_rand(0,sizeof($colorList)-1);

$float_top = rand(0,4);

$float_left = rand(0,3);

imagestring($image, 6, $space * $k, $top + $float_top, substr($authstr, $k, 1), $colorList[$colorRandom]);

}

}

for ($k = 0; $k < 20; $k++)

{

$colorRandom = mt_rand(0,sizeof($colorList)-1);

imagesetpixel($image, rand()%70 , rand()%15 , $colorList[$colorRandom]);

}

// 添加干擾線

for($k = 0; $k < 3; $k++)

{

$colorRandom = mt_rand(0, sizeof($colorList)-1);

// $todrawline = rand(0,1);

$todrawline = 1;

if($todrawline)

{

imageline($image, mt_rand(0, $board_width), mt_rand(0,$board_height), mt_rand(0,$board_width), mt_rand(0,$board_height), $colorList[$colorRandom]);

}

else

{

$w = mt_rand(0,$board_width);

$h = mt_rand(0,$board_width);

imagearc($image, $board_width - floor($w / 2) , floor($h / 2), $w, $h, rand(90,180), rand(180,270), $colorList[$colorRandom]);

}

}

imagegif($image);

imagedestroy($image);

$imagedata[] = ob_get_contents();

ob_clean();

++$i;

}

$gif = new GIFEncoder($imagedata);

Header ('Content-type:image/gif');

echo $gif->GetAnimation();

}

/**

* 調(diào)用示例

* */

session_start();

$authstr = mt_rand(1000, 9999); // 生成隨機(jī)字符串

$_SESSION['verify'] = $authstr; // 記錄session

ImageCode($authstr, 60); // 顯示GIF動(dòng)畫

更多信息請(qǐng)查看IT技術(shù)專欄