从Java脚本功能获取复选框值

Question

我有一些checkboxes如图所示

</tr>

<td style="padding-left: 10px" width="70px">

    <asp:CheckBox ID="ChkDytLek" runat="server" class="llogariDyt" GroupName="Monedha" Text="Lek" CssClass="radioMarginLeft" OnClick="ChkValidate()" />&nbsp;&nbsp; <img src="images/eagle-clipart-albanian-7.jpg" width="24px" height="15px" />

</td>

<td>

    <asp:CheckBox ID="ChkDytCAD" runat="server" GroupName="Monedha" Text="CAD" CssClass="radioMarginLeft" class="llogariDyt" OnClick="ChkValidate()" />&nbsp;&nbsp; <img src="images/CAD.png" width="24px" height="15px" />

</td>

</tr>

<tr>

    <td> </td>

    <td style="padding-left: 10px">

        <asp:CheckBox ID="ChkDytEU" runat="server" GroupName="Monedha" Text="EUR" CssClass="radioMarginLeft" class="llogariDyt" OnClick="ChkValidate()" />&nbsp;&nbsp; <img src="images/eu.png" width="24px" height="15px" />

    </td>

</tr>

但是我想限制用户选择不超过2个。我使用的是Java Script函数，但是我无法说出为什么调用该函数，但只能输入该函数，alert(1)而不能获取我的复选框的值。我称呼他们是错误的方式还是什么？

function ChkValidate() {

    var NewCount = 0

    if (document.getElementsByClassName("chkDytLek").checked = true) {

        NewCount = NewCount + 1

    }

    alert(2);

    if (document.getElementById("chkDytUSD").checked = true) {

        NewCount = NewCount + 1

    }

    alert(3);

    if (document.getElementById("chkDytEUR").checked = true) {

        NewCount = NewCount + 1

    }

    if (document.getElementById("chkDytCAD").checked = true) {

        NewCount = NewCount + 1

    }

    if (document.getElementById("chkDytCHF").checked = true) {

        NewCount = NewCount + 1

    }

    if (NewCount == 3) {

        alert('Pick Just Two Please')

        document.forms;

        return false;

    }

}

Answer 1

那是因为您的if条件中只有一个'='。if&nbsp;(document.getElementsByClassName("chkDytLek").checked&nbsp;=&nbsp;true)应该 ：if&nbsp;(document.getElementById("chkDytLek").checked&nbsp;==&nbsp;true)

Answer 2

document.getElementById("checkBoxparent").addEventListener("change", ChkValidate);var checkBoxentry = []function ChkValidate(e) {&nbsp; &nbsp; checkBoxentry.push(e.target.getAttribute("id"));&nbsp; &nbsp; if(checkBoxentry.length >= 3){&nbsp; &nbsp; &nbsp; alert("Please select only two");&nbsp; &nbsp; &nbsp; e.target.checked = false;&nbsp; &nbsp; }