/**
   *
   * @param $page   页码（1至正无穷）
   * @param $num   数据中多上行为一页
   * @param $rows   数据的总行数
   * @param $length  下标的最大长度
   * @return array
   */
  public function PageDate($page, $num , $rows , $length){
    //初始化数据
    $MaxPage = 0;         //最大页码
    $MinPage = 0;         //最小页码
    $ServerPage = 0;        //下拉框中显示的页码
    $PageData = array();      //全部的页码集合（用户下拉框选择）
    $PageShowData = array();    //用于显示下标的页码集合
    $page = intval($page);
 
    if($rows == 0){
      return $data = array(
        'page' => $page,
        'MaxPage' => $MaxPage,
        'MinPage' => $MinPage,
        'ServerPage' => $ServerPage,
        'PageData' => $PageData,
        'PageShowData' => $PageShowData
      );
    }
 
    //得到最大分页和最小分页
    $MaxPage = intval($rows / $num);
    $double = $rows % $num;
    if($double > 0.000000001)
    {
      $MaxPage += 1;
    }
    $MinPage = 1;
    $ServerPage = 1;
    //得到页码的全部项目
    for($i = 1; $i <= $MaxPage; $i++ ){
      $PageData[$i] = $i;
    }
    //对页码进行正确性改正
    if($page < $MinPage){
      $page = 1;
    }
 
    if($page > $MaxPage){
      $page = 1;
    }
    /*生成显示的页码标签*/
      //生成左侧的代码快
      if($page == $MinPage){
        $PageShowData[1] = $page;
      }
      if($page > $MinPage){
        $PageShowData[1] = $MinPage;
//        $PageShowData[2] = $page - 1; // <<
        $PageShowData[2] = '<<'; // <<
        if($page -2 > $MinPage ){
          $PageShowData[3] = $page - 2;
          $PageShowData[4] = $page - 1;
        }elseif($page -2 == $MinPage){
          $PageShowData[3] = $page - 1;
        }
        //确定选中的页码代码快
        $PageShowData[count($PageShowData) + 1] = $page;
      }
    $COUNT = count($PageShowData) + 1;
    //生成右侧的代码块
      if($page == $MaxPage){
        return $data = array(
          'page' => $page,
          'MaxPage' => $MaxPage,
          'MinPage' => $MinPage,
          'ServerPage' => $ServerPage,
          'PageData' => $PageData,
          'PageShowData' => $PageShowData
        );
      }
      if($page < $MaxPage) {
        if($MaxPage - $page >= 2){
          $j = 1;
          for($i = $COUNT; $i <= $length ; $i++){
            $PageShowData[$i] = $page + $j;
            $j ++;
            if($PageShowData[$i] == $MaxPage -1){
                 break;
              }
          }
        }
 
        $COUNT = count($PageShowData) + 1;
//        $PageShowData[$COUNT] = $page + 1; //
        $PageShowData[$COUNT] = '';
        $PageShowData[$COUNT + 1] = $MaxPage;
 
        //得到选中的参数
        $ServerPage = $PageShowData[$COUNT-1] + 1;
        if($ServerPage > $MaxPage){
          $ServerPage = 1;
        }
 
        return $data = array(
          'page' => $page,
          'MaxPage' => $MaxPage,
          'MinPage' => $MinPage,
          'ServerPage' => $ServerPage,
          'PageData' => $PageData,
          'PageShowData' => $PageShowData
        );
      }
  }