后端代码如下：
public function doadd(){

if($_SESSION['shanghuname']==null || $_SESSION['shanghuname']== ''){
$this->error("非法操作",U('Index/index'));
}

$id = $_SESSION['mid'];
//$uid=M("mydianpu")->where(id=.$dp_id)->getField("id");
$result = M("mydianpu")->where("id={$id}")->setField('id',$id);

$cat_name=$_POST['dpname'];
$cat_mon=$_POST['xmprice'];
$cat_time=$_POST['xmtime'];
$cat_xiala=$_POST['xmdanw'];



$count = count($cat_name);

$i = 0;
$data = array();

for($i=0; $i<$count;$i++){
$data[$i]['dpname'] = $cat_name[$i];
$data[$i]['xmprice'] = $cat_mon[$i];
$data[$i]['xmtime'] = $cat_time[$i];
$data[$i]['xmdanw'] = $cat_xiala[$i];

}

foreach($data as $k => $v ){

$fat['dpname']=$v;
$fat['xmprice']=$v;
$fat['xmtime']=$v;
$fat['xmdanw']=$v;
$fat['dtime']=time();
$fat['mid']=$result;
$fat['mdp_id']=$id;

if($v!=""){
M("mydianpuxm")->add($fat);
}
}


$this->redirect("Product/product_add");
$this->display();
}

前端如下：
<div >
1. <label ><span class="c-red">*</span>项目：</label>
<input type="text" class="input_yangshi" value="" maxlength="8" id="user-name" name="dpname[]">



<label ><span class="c-red">*</span>金额：</label>
<input type="text" class="input_yangshi" value="" maxlength="4" id="user-name" name="xmprice[]"

onkeypress="number()" onkeyup="filterInput()" onchange="filterInput()" onbeforepaste="filterPaste()" onpaste="return false" style="ime-mode: disabled"
>

<label ><span class="c-red">*</span>时间：</label>
<input type="text" class="input_yangshi" value="" maxlength="3" placeholder="" id="user-name" name="xmtime[]"
onkeypress="number()" onkeyup="filterInput()" onchange="filterInput()" onbeforepaste="filterPaste()" onpaste="return false" style="ime-mode: disabled"
>
<select name="xmdanw[]" >
<option value="" selected>请选择单位</option>
<option value="分钟" >分钟</option>
<option value="小时">小时</option>

</select>



</div>
<br>

<div >
2. <label ><span class="c-red">*</span>项目：</label>
<input type="text" class="input_yangshi" value="" maxlength="8" id="user-name" name=" dpname[]">



<label ><span class="c-red">*</span>金额：</label>
<input type="text" class="input_yangshi" value="" maxlength="4" id="user-name" name="xmprice[]"

onkeypress="number()" onkeyup="filterInput()" onchange="filterInput()" onbeforepaste="filterPaste()" onpaste="return false" style="ime-mode: disabled"
>

<label ><span class="c-red">*</span>时间：</label>
<input type="text" class="input_yangshi" value="" maxlength="3" placeholder="" id="user-name" name="xmtime[]"
onkeypress="number()" onkeyup="filterInput()" onchange="filterInput()" onbeforepaste="filterPaste()" onpaste="return false" style="ime-mode: disabled"
>
<select name="xmdanw[]" >
<option value="" selected>请选择单位</option>
<option value="分钟" >分钟</option>
<option value="小时">小时</option>

</select>



</div>


添加时只能把ID和提交时间添加进去，然后其他四个内容无法添加