JavaScript 运行时错误：无法获取未定义或空引用的属性“值”

JavaScript runtime error: Unable to get property 'value' of undefined or null reference

提问by Thamires Cunha

I wrote a javascript code to display the next date of a specific calendar

我写了一个 javascript 代码来显示特定日历的下一个日期

My Function

我的功能

function verificaDataReferencia(mensagem)
            {   
                if(document.getElementById("txtDataReferencia1Hidden") == null || document.getElementById("txtDataReferencia2Hidden") == null || document.getElementById("ddlDataPub") == null || document.getElementById("txtDataRefInfo") == null)

                var objtxtDataReferencia1Hidden = document.getElementById("txtDataReferencia1Hidden").value;

                var objtxtDataReferencia2Hidden = document.getElementById("txtDataReferencia2Hidden").value;

                > Breakpoint var objtxtDataArquivo = document.getElementById("ddlDataPub").value;

                var mensagem = document.getElementById("txtDataRefInfo").value;
                if((objtxtDataReferencia1Hidden == objtxtDataArquivo) || (objtxtDataReferencia2Hidden == objtxtDataArquivo))
                {
                    var x = alert(mensagem);
                    return x;
                }
            }

Html

html

<asp:TextBox style="Z-INDEX: 112; POSITION: absolute; TOP: 9px; LEFT: 572px" id="txtDataReferencia1Hidden"
                                            runat="server" CssClass="inputLabel" Width="15" Height="15px"></asp:TextBox>
                                        <asp:TextBox style="Z-INDEX: 113; POSITION: absolute; TOP: 9px; LEFT: 606px" id="txtDataReferencia2Hidden"
                                            runat="server" CssClass="inputLabel" Width="14" Height="14px"></asp:TextBox>

the problem is that the page is running well in chrome but when i run my application in IE it throw an error

问题是该页面在 chrome 中运行良好，但是当我在 IE 中运行我的应用程序时，它抛出一个错误

0x800a138f - JavaScript runtime error: Unable to get property 'value' of undefined or null reference

0x800a138f - JavaScript 运行时错误：无法获取未定义或空引用的属性“值”

please help me to overcome from this problem.

请帮助我克服这个问题。

private void Page_Load(object sender, System.EventArgs e)
        {

            if(! IsPostBack)
            {   
                txtNomePortugues.SetFocus();
                BO.Pasta pasta = new BO.Pasta(CodPasta);
                if (CodigoArquivo == 0 && !IsJustificativa && pasta.EnviaEmail)
                    btnGravar.Attributes.Add("onclick", "verificaDataReferencia(); confirmaEnvioEmail('" + GetString("Mensagem_Confirmacao_Alerta_Arquivos") + "');");
                else
                    btnGravar.Attributes.Add("onclick", "verificaDataReferencia();");

回答by Rahul Tripathi

The issue is here:

问题在这里：

var mensagem = document.getElementById("txtDataRefInfo").value;
var objtxtDataReferencia1Hidden = document.getElementById("txtDataReferencia1Hidden").value;
var objtxtDataReferencia2Hidden = document.getElementById("txtDataReferencia2Hidden").value;

Reason being txtDataRefInfo, txtDataReferencia1Hidden, txtDataReferencia2Hiddenis a server side control and not the client side. Try this:

原因是txtDataRefInfo，txtDataReferencia1Hidden，txtDataReferencia2Hidden是一个服务器端的控制，而不是客户端。尝试这个：

var objtxtDataReferencia1Hidden = document.getElementById('<%=txtDataReferencia1Hidden.ClientID%>');
var objtxtDataReferencia2Hidden = document.getElementById('<%=txtDataReferencia2Hidden.ClientID%>');
var mensagem = document.getElementById('<%=txtDataRefInfo.ClientID%>');

回答by Jerome

You need to set the ClientIDMode attribute on the control to:

您需要将控件上的 ClientIDMode 属性设置为：

ClientIDMode="Static"

This works with .Net 4.0 and upwards

这适用于 .Net 4.0 及更高版本

回答by MacKentoch

comment this line for IE it may be ok :

为 IE 注释此行可能没问题：

// > Breakpoint var objtxtDataArquivo = document.getElementById("ddlDataPub").value;

回答by Vizllx

The problem is that txtDataReferencia1Hidden and txtDataReferencia2Hidden are the server name of controls, not the client name (look the source of page from the browser).

问题是 txtDataReferencia1Hidden 和 txtDataReferencia2Hidden 是控件的服务器名称，而不是客户端名称（从浏览器查看页面源）。

Use this:

用这个：

---

---

 var objtxtDataReferencia1Hidden = document.getElementById('<%=txtDataReferencia1Hidden.ClientID%>');


 var objtxtDataReferencia2Hidden = document.getElementById('<%=txtDataReferencia2Hidden.ClientID%>');

回答by Pavel Gatnar

there is missing an action behind this if(document.getElementById("txtDataReferencia1Hidden") == null || document.getElementById("txtDataReferencia2Hidden") == null || document.getElementById("ddlDataPub") == null || document.getElementById("txtDataRefInfo") == null)

这背后缺少一个动作 if(document.getElementById("txtDataReferencia1Hidden") == null || document.getElementById("txtDataReferencia2Hidden") == null || document.getElementById("ddlDataPub") == null || document.getElementById("txtDataRefInfo") == null)

I would expect you write the line in this way (do not forget the negation using !):

我希望你以这种方式写这行（不要忘记使用!）：

if(!document.getElementById("txtDataReferencia1Hidden") || !document.getElementById("txtDataReferencia2Hidden") || !document.getElementById("ddlDataPub") || !document.getElementById("txtDataRefInfo")) return;

if(!document.getElementById("txtDataReferencia1Hidden") || !document.getElementById("txtDataReferencia2Hidden") || !document.getElementById("ddlDataPub") || !document.getElementById("txtDataRefInfo")) return;

回答by mac

You are checking to see if the elements are null in your if statement -

您正在检查 if 语句中的元素是否为空 -

if(document.getElementById("txtDataReferencia1Hidden") == null || document.getElementById("txtDataReferencia2Hidden") == null || document.getElementById("ddlDataPub") == null || document.getElementById("txtDataRefInfo") == null)

But even if they are null you are trying to get the value. Ex:

但即使它们为空，您也正在尝试获取该值。前任：

var mensagem = document.getElementById("txtDataRefInfo").value;

So if "txtDataRefInfo" is null the statement will return true and try to get the value anyways. Hence the undefined or null reference.

因此，如果“txtDataRefInfo”为空，则该语句将返回 true 并尝试获取该值。因此，未定义或空引用。