PHP实现打印类（实现队列排队打印）-php教程

打印类实现原理很简单就是用户点击打印时把数据保存到数据库,然后由js来调用打印机来打印,如果打印完了把记录删除,再执行一条打印了,具体代码如下.

类实现想法是:先把要打印的数据都收集起来,在用js调用window打印函数,目前就使用于IE.

类提供打印排队功能,说白了就是一条一条读取数据,代码如下:

class Wprint{
//收集打印代码
private $data = array();
//处理打印代码
private $handle;
public function __construct()
{
header("Content-type:text/html;charsetutf-8");
$this->link(); //链接数据库
$this->collect($_POST["username"],$_POST["content"],$_POST["ip"]);
$this->handle();
}
//链接数据库
private function link()
{
$link = mysql_connect('localhost', 'root', '123456');
mysql_select_db('shen', $link);
mysql_query('SET NAMES utf8');
}
//收集打印代码
private function collect($username,$content,$ip)
{
$code["username"] = $username;
$code["content"] = $this->check($content);
$code["ip"] = $ip;
$code["state"] = 0;
$code["priority"] = 0;
array_push($this->data,$code);//数据节点入栈
}
//处理打印代码入库
private function handle()
{
foreach($this->data as $value)
{
$sql = "insert into print(username,content,ip,state,priority)
values('{$value["username"]}','{$value["content"]}',
'{$value["ip"]}','{$value["state"]}','{$value["priority"]}')";
$query = mysql_query($sql);
if($query)
{
$id = mysql_insert_id(); //获取最近insert操作得到的ID
echo "数据收集成功,正在排队打印,排队ID为".$id;
$this->num($id);
}
else
{
echo "数据收集失败,请3秒后再一次提交";
}
}
}
//检查传人数据是否为空
private function check($string)
{
if(strlen($string) == 0 || $string == " ")
{
echo "数据收集失败,打印内容为空";
exit;
}else
{
return $string;
}
}
//获取打印排队人数
private function num($id)
{ //开源软件:phpfensi.com
$sql = "select id from print where state=0 and id<".$id." order by id asc";
$query = mysql_query($sql);
$num = mysql_num_rows($query);
echo ",您前面还有".$num."个人在排队";
}
//打印数据
public function Yprint()
{
$sql = "select id,content from print where state=0 order by id asc limit 1";
$query = mysql_query($sql);
$row = mysql_fetch_array($query);
if(!emptyempty($row["content"]))
{
echo "<script tyle=\"text/javascript\">
window.print();
</script>";
$id = $row["id"];
$sql = "update print set state=1 where id=".$id;
mysql_query($sql);
echo "打印处理完成";
}else
{
echo $row["content"];
}
}
}

思想很简单,收集数据再一个一个处理,这样就不仅解决了网络打印的问题,还避免了网络打印打印过程排队的问题.

PHP实现打印类（实现队列排队打印）

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