如何在数据绑定控件使用eval调用扩展方法 [英] How to call extension methods using Eval in a databound control

问题描述

我对int类型的简单扩展方法，所以我可以做到以下几点：

I have a simple extension method on the int type so I can do the following:

string timeLength = 61.ToTime() // timeLength will be "1:01"

这工作在code很棒，但我想在一个中继器模板使用这个扩展方法。绑定时我要做到以下几点：

This works great in code, but I want to use this extension method in a Repeater Template. When databinding I want to do the following:

<%# Eval("LengthInSeconds").ToTime() %>

这没有工作，所以我尝试：

That didn't work so I tried:

<%# ((int) Eval("LengthInSeconds")).ToTime() %>

和它仍然没有工作。 JIT编译器是不是看到我的扩展方法，我确实有在页面中正确导入语句。

and it still didn't work. The JIT compiler is not seeing my extension method and I do have the proper import statement in the page.

我对解决这个唯一的想法就是用文字控制取代评估和演示，并呼吁在code-后面的扩展方法，但无论哪种方式，我还是想知道为什么这是行不通的。

My only idea for solving this is to replace the Eval with a Literal control and call the extension method in the code-behind, but either way, I would still like to know why this isn't working.

感谢

推荐答案

看起来像我可以回答我的问题！ Asp.Net被编译的.aspx，使用.net 2.0编译器的.ascx模板。我需要以下添加到我的web.config，使其工作

Looks like I get to answer my own question! Asp.Net was compiling the .aspx,.ascx templates using the .Net 2.0 compiler. I needed to add the following to my web.config to make it work

  <system.codedom>
    <compilers>
      <compiler language="c#;cs;csharp" extension=".cs" type="Microsoft.CSharp.CSharpCodeProvider,System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" warningLevel="4">
        <providerOption name="CompilerVersion" value="v3.5"/>
        <providerOption name="WarnAsError" value="false"/>
      </compiler>
    </compilers>
  </system.codedom>

我还是要执行的评估和演示投，与（int），但至少对我来说很有意义。

I still have to perform the cast to (int) in the Eval, but that at least makes sense to me.

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