blocks|key|297820|text|您的代码是正确的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|297821|来自MSDN的代码片段意味着，编码视图引擎(例如使用<%25:+%25>时的.NET+4中的Aspx视图引擎或MVC3中的Razor视图引擎)不应该对对象的字符串值进行重新编码。|offset|length|style|CODE|297822|举个例子：|297823|string+s+=+"<tag>";
var+hs+=+MvcHtmlString.Create(s);

<%25:+s+%25>++--+outputs+"&lt;tag&gt;"
<%25:+hs+%25>+--+outputs+"<tag>"|code-block|syntax|javascript|297824|entityMap^0|0|Q|6|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@$D|S|E|T|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|U|8|@]|9|@]|A|$]]|$1|J|3|K|5|L|7|V|8|@]|9|@]|A|$M|N]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

Your code is correct.

That snippet from MSDN means that an encoding View Engine (such as the Aspx view engine in .NET 4 when using <code>&lt;%: %&gt;</code> or the Razor view engine in MVC 3) should not re-encode the string value of the object.

So for example:

<pre><code>string s = "&lt;tag&gt;";
var hs = MvcHtmlString.Create(s);

&lt;%: s %&gt; -- outputs "&amp;lt;tag&amp;gt;"
&lt;%: hs %&gt; -- outputs "&lt;tag&gt;"
</code></pre>

blocks|key|3242934|text|太糟糕了，C#不允许我们在这里覆盖%2B运算符！使用扩展方法如何？|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3242935|public+static+MvcHtmlString+Concat(this+MvcHtmlString+first,+params+MvcHtmlString[]+strings)
{
++++return+MvcHtmlString.Create(first.ToString()+%2B+string.Concat(strings.Select(s+=>+s.ToString())));
}|code-block|syntax|javascript|3242936|这可能是可以优化的，但您可以使用它运行。要证明这不会使用单元测试对字符串进行双重编码，这应该是相当简单的。|3242937|使用示例：|3242938|label.Concat(textbox,+validation)+++|3242939|现在我为我的博客添加了一个无耻的插件：Use+TagBuilder+or+HtmlTags+to+clean+up+your+HTML|offset|length|3242940|entityMap|0|LINK|mutability|MUTABLE|url|http://geekswithblogs.net/ryanohs/archive/2010/04/21/a-semantic-model-for-html-tagbuilder-and-htmltags.aspx^0|0|0|0|0|0|J|1C|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|Z|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|10|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|11|8|@]|9|@]|A|$]]|$1|K|3|L|5|D|7|12|8|@]|9|@]|A|$E|F]]|$1|M|3|N|5|6|7|13|8|@]|9|@$O|14|P|15|1|16]]|A|$]]|$1|Q|3|-4|5|6|7|17|8|@]|9|@]|A|$]]]|R|$S|$5|T|U|V|A|$W|X]]]]

Too bad C# won't let us override the + operator here! How about using an extension method instead?

<pre><code>public static MvcHtmlString Concat(this MvcHtmlString first, params MvcHtmlString[] strings)
{
 return MvcHtmlString.Create(first.ToString() + string.Concat(strings.Select(s =&gt; s.ToString())));
}
</code></pre>

This could probably be optimized, but you can run with it. It should be fairly trivial to prove that this doesn't double encode strings with a unit test.

Usage sample:

<pre><code>label.Concat(textbox, validation) 
</code></pre>

And now a shameless plug for my blog: <a href="http://geekswithblogs.net/ryanohs/archive/2010/04/21/a-semantic-model-for-html-tagbuilder-and-htmltags.aspx" rel="noreferrer">Use TagBuilder or HtmlTags to clean up your HTML</a>

blocks|key|3242953|text|我选择了这种方法：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3242954|++++private+static+MvcHtmlString+Concat(params+MvcHtmlString[]+items)
++++{
++++++++var+sb+=+new+StringBuilder();
++++++++foreach+(var+item+in+items.Where(i+=>+i+!=+null))
++++++++++++sb.Append(item.ToHtmlString());
++++++++return+MvcHtmlString.Create(sb.ToString());
++++}|code-block|syntax|javascript|3242955|它只是一个实用方法，我在HtmlHelper的扩展方法的类中使用它。|3242956|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

I went for this approach:

<pre><code> private static MvcHtmlString Concat(params MvcHtmlString[] items)
 {
 var sb = new StringBuilder();
 foreach (var item in items.Where(i =&gt; i != null))
 sb.Append(item.ToHtmlString());
 return MvcHtmlString.Create(sb.ToString());
 }
</code></pre>

It's just a utility method that I use inside the classes with extension methods for HtmlHelper.

blocks|key|303068|text|我知道这太老了，但是还有另一种方法(我发现它更优雅)是使用字符串方法Concat的重载，元数据定义是|type|unstyled|depth|inlineStyleRanges|entityRanges|data|303069|public+static+String+Concat(params+object[]+args);|code-block|syntax|javascript|303070|这基本上是对传入的每个对象执行ToStrings操作，然后连接结果并返回连接后的字符串。|303071|因此，最终结果将是：|303072|var+result+=+MvcHtmlString.Create(
++++string.Concat(
++++++++label,+textbox,+validation
++++)
);|303073|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|D|7|S|8|@]|9|@]|A|$E|F]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

I know this is super old, but yet another way (which I find to be more elegant), is to use an overload of the String method Concat, which metadata definition is

<pre><code>public static String Concat(params object[] args);
</code></pre>

that basically ToStrings each one of the objects passed in and then concatenates the results and returns the concatenated string.

So the final result would be:

<pre><code>var result = MvcHtmlString.Create(
 string.Concat(
 label, textbox, validation
 )
);
</code></pre>

I have some doubts about how to concatenate MvcHtmlString instances because of this information found in <a href="http://msdn.microsoft.com/en-us/library/system.web.mvc.mvchtmlstring.aspx" rel="noreferrer">MSDN</a> :

<blockquote>
 MvcHtmlString Class Represents an HTML-encoded string that
 should not be encoded again
</blockquote>

Do I risk that strings are HTML-encoded twice when using code like this:

<pre><code>var label = Html.LabelFor(model =&gt; model.Email);
var textbox = Html.TextBoxFor(model =&gt; model.Email);
var validation = Html.ValidationMessageFor(model =&gt; model.Email);

var result = MvcHtmlString.Create(
 label.ToString() + textbox.ToString() + validation.ToString());
</code></pre>

(note: this is supposed to go into an HtmlHelper extension method to reduce code-duplication in views).

How to concatenate several MvcHtmlString instances

我对如何连接MvcHtmlString实例有一些疑问，因为在中可以找到以下信息： MvcHtmlString类表示不应再次编码的HTML编码字符串在使用这样的代码时，我是否冒着对字符串进行两次HTML编码的风险：var label = Html.LabelFor(model => model.Email);var te...

问如何连接多个MvcHtmlString实例
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