Question

我在页面nice.php上的表单内选择一个下拉列表，使用按钮提交

<form action="nice.php" method="post">
<select name="CarList">
<option value="0"> - Select Car - </option>
<option value="AM">Aston Martin</option>
<option value="KG">Koenigsegg</option>
<option value="MB">Mercedes Benz</option>
</select>

<input type="submit">
</form>

在做出选择之后，是否可以提交表单，重新加载同一页面但是从下拉列表中的值变为php变量$SelectedCar？

Answer 1

if(!empty($_POST['CarList'])){
    $SelectedCar = $_POST['CarList'];
    echo $SelectedCar;
}else{
    echo '<p>No Selection has been made and submitted yet</p>';
}

Answer 2

将代码添加到php页面的顶部并删除表单标记。这应该回到同一页面。（请记住检查是否在$ _POST中设置了任何变量）

我还没有测试过这个建议，但它应该可行

**编辑。

所以你的HTML应该是这样的：

    <?php 
    if(isset($_POST['CarList']) && !empty(isset($_POST['CarList'])){
        $CarListValue = $_POST['CarList'];

        if($CarListValue != 0){ // a selection has been made using car list
            $SelectedCar = $CarListValue
            echo $SelectedCar  // should print either 'AM', 'KG', or 'MB'
        }
        else{
            echo '<p>No Selection has been made and submitted yet</p>';
        }
    }

    ?>

    <html>
    <head>
    <title>Nice.php</title>
    </head>
    <body>
        <select name="CarList">
        <option value="0"> - Select Car - </option>
        <option value="AM">Aston Martin</option>
        <option value="KG">Koenigsegg</option>
        <option value="MB">Mercedes Benz</option>
        </select>

        <submit>Submit Form</submit>
    </body>
    </html>

然后你可以将你的验证带到另一个级别并改变这样的PHP代码：

    <?php 

    $ValidCars = array('AM','KG','MB');

    if(isset($_POST['CarList']) && !empty(isset($_POST['CarList'])){
        $CarListValue = $_POST['CarList'];

        if(in_array($CarListValue,strtoupper($ValidCars),false) !== true){
            die('<b>The car selection you made is invalid</b>');
        }

        if($CarListValue != 0){ // a selection has been made using car list
            $SelectedCar = $CarListValue
            echo $SelectedCar  // should print either 'AM', 'KG', or 'MB'
        }
        else{
            echo '<p>No Selection has been made and submitted yet</p>';
        }
    }

    ?>

我只想再说一遍，这段代码未经测试但理论上代码应该没有任何错误

从页面上的下拉选择的php中检索post值

2 个答案: