php thinkphp imagepng无法显示图片

php代码浏览器可正常显示图片,thinkPhp控制器不可行在header前加上

ob_clean ();

即可

thinkphp 控制器代码

/** * 显示图标 */public function icon() {//清除输出,去掉前面的htmlob_clean ();header ( "Content-type: image/png" );// 文件名$type = $_GET ["type"];if (empty ( $_GET ["color"] )) {$fileName = $type . '.png';} else {$color = $_GET ["color"];$fileName = $type . '_' . $color . '.png';}// 旋转角度$angle = $_GET ["angle"];if ($angle > 180) {$angle = 360 - $angle;} else {$angle = - $angle;}// 文件绝对路径$fileName2 = IconPath . $fileName;// 实例图片$im = imagecreatefrompng ( $fileName2 );$alpha = imagecolorallocatealpha ( $im, 0, 0, 0, 127 );$re = imagerotate ( $im, $angle, $alpha );// 保留透明度imagesavealpha ( $re, true );// 输出到浏览器imagepng ( $re );imagedestroy ( $im );imagedestroy ( $re );}