javascript - 为什么在 Ajax 中从 Label 读取值不起作用

Question

我正在尝试使用 Ajax 从 Label(asp) 读取值。但我总是得不到定义:|

我的代码是:

function NIS2USD() {
    var from = document.getElementById("NIS").value;
    var to = document.getElementById("USD").value;
    var amount = document.getElementById("totalAmountLabel").value;
    request = new XMLHttpRequest();
    request.onreadystatechange = ProcessResponse;
    request.open("GET", "Convert.aspx?from=" + num1 + "&to=" + num2 + "&amount=" +    amount, true);
    request.send();
}
function USD2NIS() {
    var from = document.getElementById("USD").value;
    var to = document.getElementById("NIS").value;
    var amount = document.getElementById("totalAmountLabel").value;
    request = new XMLHttpRequest();
    request.onreadystatechange = ProcessResponse;
    request.open("GET", "Convert.aspx?from=" + num1 + "&to=" + num2 +  "&amount="+amount, true);
    request.send();
}
function ProcessResponse() {
    if (request.readyState == 4 && request.status == 200) {
        document.getElementById("totalAmountLabel").innerHTML = request.responseText;
    }
}

我的标签定义是:

<asp:Label ID="totalAmountLabel" runat="server" Text="Label"></asp:Label>

为什么我总是遇到undef？

Answer 1

尝试此操作来获取标签的客户端 ID。

var amount = document.getElementById("<%=totalAmountLabel.ClientID%>").innerHTML;