我在uploadError时javascript函数从AJAX工具包AsyncFileUpload如下：

I have the following in the uploadError javascript function for AsyncFileUpload from AJAX toolkit:

function uploadError(sender, args) {
    document.getElementById("<%# uploadResult.ClientID %>").innerText = args.get_fileName(), "<span style='color:red;'>" + args.get_errorMessage() + "</span>";
}

不幸的是，客户端ID 调用返回空，所以JavaScript错误。

Unfortunately the ClientID call returns Null, so the javascript errors.

我也注意到，没有我的控制有通常的.NET格式一旦加载页面：如：

I have also noticed that none of my controls have the usual .NET format once the page is loaded: E.G.:

<asp:Label runat="server" Text="Select an image to upload it to this stock item...." ID="uploadResult" /> 

通常会呈现这样的：

Would usually render like this:

<span id="ctl00_ContentPlaceHolder1_uploadResult">Choose a webstock file to upload...</span>

但有了这个文件，它呈现为：

But with this file it is rendering as:

<span id="uploadResult">Select an image to upload it to this stock item....</span>

我presume这是同样的问题，但不知道为什么它的发生。

I presume this is the same issue, but don't know why it's happening.

推荐答案

现在的问题是，你正在使用的＆LT;％＃语法，只执行约束力（evals ）。

The problem is you are using the <%# syntax which is only executed on binding (evals).

您应该使用＆LT;％= 语法，这将永远执行

You should be using <%= syntax which will always execute.

例如：

function uploadError(sender, args)
{
    document.getElementById('<%= uploadResult.ClientID %>').innerText = 
        args.get_fileName() + "<span style='color:red;'>" + 
        args.get_errorMessage() + "</span>";
}

Reference关于asp.net在线语法的更多信息。

数据绑定语法

内联语法

编辑：请注意你有，提交作业的innerText 这也将是一个问题，如果它不是一个错字。

Note you had , in your assignment to innerText which would also be an issue if it is not a typo.