使用Javascript通過鏈接獲取並發送文本值

Question

我正在嘗試通過鏈接將輸入的文本發送到框中。 請在下面查看我的代碼。 由於某種原因它沒有通過發送嗎？

<script>
    var discountCode = document.getElementById("discountCode").value;
        openPage = function() {
        location.href = "payment.php?discount="+discountCode;
    }                       
</script>
<a href ="javascript:openPage()" class="btn btn-warning">Purchase</a>

Answer 1

您將在頁面加載后立即讀取該值，而不是單擊鏈接時。 您只需要將行移動到函數中：

<script>
    openPage = function() {
        var discountCode = document.getElementById("discountCode").value;
        location.href = "payment.php?discount="+discountCode;
    }                       
</script>
<a href ="javascript:openPage()" class="btn btn-warning">Purchase</a>

或可替代先手元素在頁面加載時（假設這個腳本是在經過了參考discountCode元素），然后閱讀函數的值：

<script>
    var discountCode = document.getElementById("discountCode");
    openPage = function() {
        location.href = "payment.php?discount="+discountCode.value;
    }                       
</script>
<a href ="javascript:openPage()" class="btn btn-warning">Purchase</a>