Javascript 如何使用php在循环中单击按钮时显示数据

我有一个项目，其中我在while循环中显示一个按钮标记。在每次单击按钮时，我都希望显示一个带有相应用户ID的警报框。这是我的密码：

    <?php 
 $data = mysql_query("Select RegisterId,FName,Image1  from Information where RegisterID='$profileMonth1'") or die(mysql_error());
 while ($dis1 = mysql_fetch_array($data)) {
?>    
<div id="demo1" value="<?php echo "$RegisterId" ?>">
<button onClick="validate()">Show Interest</button>
</div> 
<?php } ?>

但它总是向我显示最后一个用户id。。而我想在everyclick上显示每个用户的用户ID

有人能帮忙吗？

在你的代码中试试这个

HTML:

---

在这里，您调用的函数是未定义的

validate1

，而且您不需要在函数声明中获取任何参数，因为您在调用它时没有传递任何参数

 <?php 
 $data = mysql_query("Select RegisterId,FName,Image1  from Information where RegisterID='$profileMonth1'") or die(mysql_error());
 while ($dis1 = mysql_fetch_array($data)) {
?>    
<div id="demo" value="<?php echo "$RegisterId" ?>">
<button onClick="validate()">Show Interest</button>
</div> 

---

您的代码需要一些修改

首先，您已经准备好向javascript函数发送

id

，但是，您没有向它传递

id

PHP

<?php 
$data = mysql_query("Select RegisterId,FName,Image1  from Information where RegisterID='$profileMonth1'") or die(mysql_error());
while ($dis1 = mysql_fetch_array($data)) {
?>
<div id="demo1" value="<?php echo $dis1['RegisterId'];?>">
    <button onClick="validate('<?php echo $dis1['RegisterId'];?>')">Show Interest</button>
</div>
<?php } ?>

---

使用这段代码，您的点击甚至不应该返回最后一个id。您的javascript函数看起来不太好

这应该行得通

<?php 
$data = mysql_query("Select RegisterId,FName,Image1  from Information where RegisterID='$profileMonth1'") or die(mysql_error());
while ($dis1 = mysql_fetch_array($data)) {
?>
<!-- removed id attribute, as they're unique, you can't set it to every div. 
If you really need id attribute, you can set one by using your RegisterId (e.g. id="demo-<?php echo $RegisterId; ?>)
And moved value attribute to button tag, it's much more useful in it. -->
<div>
<button onClick="validate(this)" value="<?php echo "$RegisterId" ?>">Show Interest</button>
</div> 
<?php } ?>

---

通过这种方式，您可以更轻松地在其他内容中使用它。

在您的javascript代码中，您正在寻找一个应该是demo1的id demo2。此外，它应该是document.getElementById（“demo1”）.innerHTML。这将为您提供div上的文本。此外，您的php代码需要一些改进。我会在下面的答案中写一个解决方案你在初始化$RegisterId变量吗？@Erick在问题中说他得到了所有id，但它只提醒最后一个id。

 <?php 
 $data = mysql_query("Select RegisterId,FName,Image1  from Information where RegisterID='$profileMonth1'") or die(mysql_error());
 while ($dis1 = mysql_fetch_array($data)) {
?>    
<div id="demo" value="<?php echo "$RegisterId" ?>">
<button onClick="validate()">Show Interest</button>
</div> 

function validate(){
    var id2 = document.getElementById('demo').getAttribute('value');
    alert(id2);
}

<?php 
$data = mysql_query("Select RegisterId,FName,Image1  from Information where RegisterID='$profileMonth1'") or die(mysql_error());
while ($dis1 = mysql_fetch_array($data)) {
?>
<div id="demo1" value="<?php echo $dis1['RegisterId'];?>">
    <button onClick="validate('<?php echo $dis1['RegisterId'];?>')">Show Interest</button>
</div>
<?php } ?>

function validate1(id2) {
  // var id2;
  //id2 = document.getElementById('demo2').getAttribute('value');
  alert(id2);
}

<?php 
$data = mysql_query("Select RegisterId,FName,Image1  from Information where RegisterID='$profileMonth1'") or die(mysql_error());
while ($dis1 = mysql_fetch_array($data)) {
?>
<!-- removed id attribute, as they're unique, you can't set it to every div. 
If you really need id attribute, you can set one by using your RegisterId (e.g. id="demo-<?php echo $RegisterId; ?>)
And moved value attribute to button tag, it's much more useful in it. -->
<div>
<button onClick="validate(this)" value="<?php echo "$RegisterId" ?>">Show Interest</button>
</div> 
<?php } ?>

function validate(element){
    alert(element.value)
}