php生成缩略图类，支持自定义高和宽。还支持按高和宽截图

php教程生成缩略图类，支持自定义高和宽。还支持按高和宽截图

class resizeimage 
{ 
    //图片类型 
    var $type; 
    //实际宽度 
    var $width; 
    //实际高度 
    var $height; 
    //改变后的宽度 
    var $resize_width; 
    //改变后的高度 
    var $resize_height; 
    //是否裁图 
    var $cut; 
    //源图象 
    var $srcimg; 
    //目标图象地址 
    var $dstimg; 
    //临时创建的图象 
    var $im; 
    function resizeimage($img, $wid, $hei,$c,$dstpath) 
    { 
        $this->srcimg = $img; 
        $this->resize_width = $wid; 
        $this->resize_height = $hei; 
        $this->cut = $c; 
        //图片的类型 

$this->type = strtolower(substr(strrchr($this->srcimg,"."),1)); 
        //初始化图象 
        $this->initi_img(); 
        //目标图象地址 
        $this -> dst_img($dstpath); 
        //-- 
        $this->width = imagesx($this->im); 
        $this->height = imagesy($this->im); 
        //生成图象 
        $this->newimg(); 
        ImageDestroy ($this->im); 
    } 
    function newimg() 
    { 
        //改变后的图象的比例 
        $resize_ratio = ($this->resize_width)/($this->resize_height); 
        //实际图象的比例 
        $ratio = ($this->width)/($this->height); 
        if(($this->cut)=="1") 
        //裁图 
        { 
            if($ratio>=$resize_ratio) 
            //高度优先 
            { 
                $newimg = imagecreatetruecolor($this->resize_width,$this->resize_height); 
                imagecopyresampled($newimg, $this->im, 0, 0, 0, 0, $this->resize_width,$this->resize_height, (($this->height)*$resize_ratio), $this->height); 
                ImageJpeg ($newimg,$this->dstimg); 
            } 
            if($ratio<$resize_ratio) 
            //宽度优先 
            { 
                $newimg = imagecreatetruecolor($this->resize_width,$this->resize_height); 
                imagecopyresampled($newimg, $this->im, 0, 0, 0, 0, $this->resize_width, $this->resize_height, $this->width, (($this->width)/$resize_ratio)); 
                ImageJpeg ($newimg,$this->dstimg); 
            } 
        } 
        else
        //不裁图 
        { 
            if($ratio>=$resize_ratio) 
            { 
                $newimg = imagecreatetruecolor($this->resize_width,($this->resize_width)/$ratio); 
                imagecopyresampled($newimg, $this->im, 0, 0, 0, 0, $this->resize_width, ($this->resize_width)/$ratio, $this->width, $this->height); 
                ImageJpeg ($newimg,$this->dstimg); 
            } 
            if($ratio<$resize_ratio) 
            { 
                $newimg = imagecreatetruecolor(($this->resize_height)*$ratio,$this->resize_height); 
                imagecopyresampled($newimg, $this->im, 0, 0, 0, 0, ($this->resize_height)*$ratio, $this->resize_height, $this->width, $this->height); 
                ImageJpeg ($newimg,$this->dstimg); 
            } 
        } 
    } 
    //初始化图象 
    function initi_img() 
    { 
        if($this->type=="jpg") 
        { 
            $this->im = imagecreatefromjpeg($this->srcimg); 
        } 
        if($this->type=="gif") 
        { 
            $this->im = imagecreatefromgif($this->srcimg); 
        } 
        if($this->type=="png") 
        { 
            $this->im = imagecreatefrompng($this->srcimg); 
        } 
    } 
    //图象目标地址 
    function dst_img($dstpath) 
    { 
        $full_length  = strlen($this->srcimg); 
        $type_length  = strlen($this->type); 
        $name_length  = $full_length-$type_length; 

        $name         = substr($this->srcimg,0,$name_length-1); 
        $this->dstimg = $dstpath; 

//echo $this->dstimg; 
    } 
} 

$resizeimage = new resizeimage("11.jpg", "200", "150", "1","17.jpg");