如何在源文件中声明条件 [英] How to declare if condition in source file

问题描述

如何声明是否在源文件中

How to declare if in source file

<% if(Eval("img_url") != ""){%>

我正在这样使用，但显示错误

请任何人可以帮助我
在此先感谢

我可以这样声明吗?

I am using like this but it shown error

Please any one can help me
Thanks in advance

can i declare like this:

public string GetAppropriateHTML()
    {
        string html = "";
        if (Eval("a_comment_counter") == "")
        {
            html = "<p style="font-size: .9em; text-align: right; color: #808080; border-bottom: 1px #d8d8d8 solid; padding-bottom: 10px"><i>0 comments</i>";
        }
        else
        {
            html = "<a href="a_comments.aspx?a_id=<%# Eval("a_id")%>"><%# Eval("a_comment_counter")%> comments</a>";
        }
        return html;
    }

但不支持

but it not supported

推荐答案

您不能将if-else构造与Eval函数一起使用.
这是bcoz:
评估只能写在<％#％>中.而if-else不能写在那里.
另外，如果条件不能应用于Eval等.
应用条件 [

You cant use if-else construct with Eval function.
This is bcoz:
Eval can be written only in <%# %> whereas if-else cant be written there.
Also, if condition cant be applied to Eval etc.
Applying condition[^]
This link will be very careful and will definitely solve your problem.

您的示例不是cpomplete，或者您没有全部复制:

Your sample either isn''t cpomplete, or you just didn''t copy it all:

<% if(Eval("img_url") != ""){%>
  some html goes here
<%} else {%>
  some different html goes here
<%}%>

请注意最后的右括号.

我更喜欢在orer的代码中放置逻辑，以保持aspx文件尽可能的干净.

Notice the closing brace at the end.

I prefer to put logic in the code-behind in orer to keep the aspx file as clean as possible.

public string GetAppropriateHTML()
{
    string html = "";
    if (Eval("img_url") != "")
    {
        html = "some html goes here";
    }
    else
    {
        html = "some other html goes here"
    }
    return html;
}

这样可以将aspx文件中的混乱情况减少为:

Which reduces the clutter in the aspx file to this:

<%=GetAppropriateHTML() %>

这篇关于如何在源文件中声明条件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！