PHP中的！is_numeric函数不接受NULL VALUE(The !is_numeric function in PHP does not accept NULL VALUE)

 就像是： 
 
for($row=1; $row < $highestRow; ++$row){
    $objPHPExcel->getActiveSheet()->removeRow($row,$row);
}
 
 每次迭代都需要花费大量时间，而且大部分都是冗余的.... 
 
 如果您需要从现有工作表中删除所有数据，请使用 
 
    $objPHPExcel->getActiveSheet()->removeRow(1,$highestRow);
 
 相反，不需要循环（特别是虚假循环删除已经多次删除的内容），在一次调用中删除所有内容 
 
 我也很困惑为什么你使用一个库来读取文件（excel Reader）和另一个用于编写（PHPExcel）的时候你可以使用单个库（PHPExcel）来实现这两个目的....虽然你似乎做得很好很少有excel Reader，因为你正在迭代该电子表格中的每个单元格，然后似乎根本没有对它做任何事情 
 
 编辑 
 
 我最后评论的意思是： 
 
<?php
......
ini_set('include_path', ini_get('include_path').';../Classes/');
include_once 'PHPExcel.php';
include_once 'Excel2007.php';

$excel->read('sample.xls'); // added excel reader from which we need to take some values   

$x=1;
while($x<=$excel->sheets[0]['numRows']) { // reading row by row 
    $y=1;
    while($y<=$excel->sheets[0]['numCols']) {// reading column by column 
        $cell = isset($excel->sheets[0]['cells'][$x][$y]) ? $excel->sheets[0]['cells'][$x][$y] : '';
        $target = $cell;

        /* some lines of code using curl to fetch data for $target value
            ........... */
        //below is the code which retrives data from html table and saves into excel file.
        $url='results/'.$target.'.html';
        include_once('dom.php');

        $html=file_get_html($url);

        $objPHPExcel = new PHPExcel();
        $objPHPExcel->getProperties()->....//set some properties//

        $record_find='first';

        foreach($html->find('table#GridView1') as $e){
            if($record_find=='first')
                $i=1;
            $j=0;

            foreach($e->find('tr') as $e1){
                $distno=trim($e1->find('td', 0)->innertext);
                $acno=trim($e1->find('td', 1)->innertext);
                $partno=trim($e1->find('td', 2)->innertext);
                $objPHPExcel->setActiveSheetIndex(0);
                $objPHPExcel->getActiveSheet()->SetCellValue('A'.$j, $distno);
                $objPHPExcel->getActiveSheet()->SetCellValue('B'.$j, $acno);
                $objPHPExcel->getActiveSheet()->SetCellValue('C'.$j, $partno);

                $j++;
            }
        }

        $objPHPExcel->getActiveSheet()->setTitle($target);

        $objWriter = new PHPExcel_Writer_Excel2007($objPHPExcel); 
        $objWriter->save('excelresult/'.$target.'.xlsx');

        $objPHPExcel->disconnectWorksheets();
        unset($objPHPExcel);

        $y++;
    }
    $x++;
} 
?>

Something like:
 
for($row=1; $row < $highestRow; ++$row){
    $objPHPExcel->getActiveSheet()->removeRow($row,$row);
}
 
Is going to take a lot of time with each iteration, and most of it redundant as well....
 
If you need to remove all data from the existing worksheet then use
 
    $objPHPExcel->getActiveSheet()->removeRow(1,$highestRow);
 
instead, no need to loop (especially spurious looping removing what has already been removed many times over), remove everything in a single call
 
I'm also puzzled why you're using one library for reading files (excel Reader) and another for writing (PHPExcel) when you could use a single library (PHPExcel) for both purposes.... although you seem to be doing very little with excel Reader because you're iterating over every cell in that spreadsheet and don't then seem to do anything with it at all
 
EDIT
 
What I meant by that last comment was something like:
 
<?php
......
ini_set('include_path', ini_get('include_path').';../Classes/');
include_once 'PHPExcel.php';
include_once 'Excel2007.php';

$excel->read('sample.xls'); // added excel reader from which we need to take some values   

$x=1;
while($x<=$excel->sheets[0]['numRows']) { // reading row by row 
    $y=1;
    while($y<=$excel->sheets[0]['numCols']) {// reading column by column 
        $cell = isset($excel->sheets[0]['cells'][$x][$y]) ? $excel->sheets[0]['cells'][$x][$y] : '';
        $target = $cell;

        /* some lines of code using curl to fetch data for $target value
            ........... */
        //below is the code which retrives data from html table and saves into excel file.
        $url='results/'.$target.'.html';
        include_once('dom.php');

        $html=file_get_html($url);

        $objPHPExcel = new PHPExcel();
        $objPHPExcel->getProperties()->....//set some properties//

        $record_find='first';

        foreach($html->find('table#GridView1') as $e){
            if($record_find=='first')
                $i=1;
            $j=0;

            foreach($e->find('tr') as $e1){
                $distno=trim($e1->find('td', 0)->innertext);
                $acno=trim($e1->find('td', 1)->innertext);
                $partno=trim($e1->find('td', 2)->innertext);
                $objPHPExcel->setActiveSheetIndex(0);
                $objPHPExcel->getActiveSheet()->SetCellValue('A'.$j, $distno);
                $objPHPExcel->getActiveSheet()->SetCellValue('B'.$j, $acno);
                $objPHPExcel->getActiveSheet()->SetCellValue('C'.$j, $partno);

                $j++;
            }
        }

        $objPHPExcel->getActiveSheet()->setTitle($target);

        $objWriter = new PHPExcel_Writer_Excel2007($objPHPExcel); 
        $objWriter->save('excelresult/'.$target.'.xlsx');

        $objPHPExcel->disconnectWorksheets();
        unset($objPHPExcel);

        $y++;
    }
    $x++;
} 
?>