//缩略图部分------------------------------------------------------------
//判断缩略图大小函数-----
function ResizeImage($im,$maxwidth,$maxheight,$name){ 
    $width = imagesx($im); 
    $height = imagesy($im); 
    if(($maxwidth && $width > $maxwidth) || ($maxheight && $height > $maxheight)){ 
        if($maxwidth && $width > $maxwidth){ 
            $widthratio = $maxwidth/$width; 
            $RESIZEWIDTH=true; 
        } 
        if($maxheight && $height > $maxheight){ 
            $heightratio = $maxheight/$height; 
            $RESIZEHEIGHT=true; 
        } 
        if($RESIZEWIDTH && $RESIZEHEIGHT){ 
            if($widthratio < $heightratio){ 
                $ratio = $widthratio; 
            }else{ 
                $ratio = $heightratio; 
            } 
        }elseif($RESIZEWIDTH){ 
            $ratio = $widthratio; 
        }elseif($RESIZEHEIGHT){ 
            $ratio = $heightratio; 
        } 
        $newwidth = $width * $ratio; 
        $newheight = $height * $ratio; 
        if(function_exists("imagecopyresampled")){ 
              $newim = imagecreatetruecolor($newwidth, $newheight); 
              imagecopyresampled($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height); 
        }else{ 
            $newim = imagecreate($newwidth, $newheight); 
              imagecopyresized($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height); 
        } 
        ImageJpeg ($newim,$smalladdrname.$name.".jpg"); 
        ImageDestroy ($newim); 
    }else{ 
        ImageJpeg ($im,$smalladdrname.$name.".jpg"); 
    } 
    } 
    //生成部分
    if($_FILES['image']['size']){ 
    if($_FILES['image']['type'] == "image/pjpeg"){ 
        $im = imagecreatefromjpeg($bigaddrname.$exname); 
    }elseif($_FILES['image']['type'] == "image/x-png"){ 
        $im = imagecreatefrompng($bigaddrname.$exname); 
    }elseif($_FILES['image']['type'] == "image/gif"){ 
        $im = imagecreatefromgif($bigaddrname.$exname); 
    } 
    if($im){ 
        if(file_exists($smalladdrname.".jpg")){ 
            unlink($smalladdrname.".jpg"); 
        } 
        ResizeImage($im,$RESIZEWIDTH,$RESIZEHEIGHT,$smalladdrname); 
        ImageDestroy ($im); 
    } 
    }
    echo "<div align='center'><a href='javascript:window.history.back()'>上传成功</a></div>";
}
//缩略图结束----------------------------------------------------- 
  
}

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