/**

	* 生成缩略图

	* $imgSrc			图片源路径

	* $resize_width		图片宽度

	* $resize_height	图片高度

	* $dstimg			缩略图路径

	* $isCut			是否剪切图片

	*/

	public function reSizeImg($imgSrc, $resize_width, $resize_height, $dstimg, $isCut = false) {

        //图片的类型

        $type = substr(strrchr($imgSrc, "."), 1);

        //初始化图象

        if ($type == "jpg" || $type == "jpeg") {

            $im = imagecreatefromjpeg($imgSrc);

        }

        if ($type == "gif") {

            $im = imagecreatefromgif($imgSrc);

        }

        if ($type == "png") {

            $im = imagecreatefrompng($imgSrc);

        }

        $width = imagesx($im);

        $height = imagesy($im);

        //生成图象

        //改变后的图象的比例

        $resize_ratio = ($resize_width) / ($resize_height);

        //实际图象的比例

        $ratio = ($width) / ($height);

        if (($isCut) == 1) {

            if ($ratio >= $resize_ratio) {

				//高度优先

                $newimg = imagecreatetruecolor($resize_width, $resize_height);

                imagecopyresampled($newimg, $im, 0, 0, 0, 0, $resize_width, $resize_height, (($height) * $resize_ratio), $height);

                ImageJpeg($newimg, $dstimg);

            }

            if ($ratio < $resize_ratio) {

				//宽度优先

                $newimg = imagecreatetruecolor($resize_width, $resize_height);

                imagecopyresampled($newimg, $im, 0, 0, 0, 0, $resize_width, $resize_height, $width, (($width) / $resize_ratio));

                ImageJpeg($newimg, $dstimg);

            }

        } else {

            if ($ratio >= $resize_ratio) {

                $newimg = imagecreatetruecolor($resize_width, ($resize_width) / $ratio);

                imagecopyresampled($newimg, $im, 0, 0, 0, 0, $resize_width, ($resize_width) / $ratio, $width, $height);

                ImageJpeg($newimg, $dstimg);

            }

            if ($ratio < $resize_ratio) {

                $newimg = imagecreatetruecolor(($resize_height) * $ratio, $resize_height);

                imagecopyresampled($newimg, $im, 0, 0, 0, 0, ($resize_height) * $ratio, $resize_height, $width, $height);

                ImageJpeg($newimg, $dstimg);

            }

        }

        ImageDestroy($im);

    }