Question

以下代码运行第一个控件罚款，第二个控件失败，尽管完全相同：

if (document.getElementById("employeeID").value == "") {
    document.getElementById("lblEmp").textContent = "Employee Name is required";
    ret = false;
} else {
    document.getElementById("lblEmp").textContent = "";
}

if (document.getElementById("grossSalary").value == "") {
    document.getElementById("lblGrossSalary").textContent = "Gross Salary is required";
    ret = false;
} else  {
    document.getElementById('#lblGrossSalary').textContent = "";
}

代码正在按预期运行employeeID控件，但在grossSalary控件上抛出主题错误。

剃刀：

<div class="form-group">
    @Html.LabelFor(model => model.employeeID, htmlAttributes: new { @class = "control-label col-md-2" })
    <div id="inner" class="col-md-10">
        @Html.EditorFor(model => model.employeeID, new { htmlAttributes = new { @class = "form-control" } })
        @Html.ValidationMessageFor(model => model.employeeID, "", new { @class = "text-danger" })
        <label id="lblEmp" style="color:red"></label>
    </div>
</div>
<div class="form-group">
    @Html.LabelFor(model => model.grossSalary, htmlAttributes: new { @class = "control-label col-md-2" })
    <div id="inner" class="col-md-10">
        @Html.EditorFor(model => model.grossSalary, new { htmlAttributes = new { @class = "form-control"} })
        <label id="lblGrossSalary" style="color:red"></label>
    </div>
</div>

Answer 1

应该是

document.getElementById('lblGrossSalary').textContent = "";

而不是

document.getElementById('#lblGrossSalary').textContent = "";

在你的最后一个块中

Answer 2

看起来问题可能如下：

else {
     document.getElementById('#lblGrossSalary').textContent = "";
 }

将('#lblGrossSalary')更改为('lblGrossSalary')。

Answer 3

你只能在对象上使用点（。）运算符，所以如果它是undefined或null并且想要＆＃34; .value＆＃34;你会收到一个错误。

我重新编写了你的代码，但这应该适合你！它也更清洁：）

Error: unable to load the file libsbmlj.jar.  It is likely
your LD_LIBRARY_PATH environment variable or CLASSPATH variable
does not include the directory containing the libsbmlj.jar file.

JavaScript - 无法获得财产＆＃39;价值＆＃39;未定义或空引用的

3 个答案: