像Helper.BeginForm（）一样创建MVC3RazorHelper-CreatingMVC3RazorHelperlikeHelper.BeginForm()

36  

It's totally possible. The way this is done in MVC with things like Helper.BeginForm is that the function must return an object that implements IDisposable.

这完全有可能。在MVC中使用Helper.BeginForm这样的方法是函数必须返回一个实现IDisposable的对象。

The IDisposable interface defines a single method called Dispose which is called just before the object is garbage-collected.

IDisposable接口定义了一个名为Dispose的方法，该方法在对象被垃圾收集之前调用。

In C#, the using keyword is helpful to restrict the scope of an object, and to garbage-collect it as soon as it leaves scope. So, using it with IDisposable is natural.

在C＃中，using关键字有助于限制对象的范围，并在它离开范围时立即对其进行垃圾收集。因此，将它与IDisposable一起使用是很自然的。

You'll want to implement a Section class which implements IDisposable. It will have to render the open tag for your section when it is constructed, and render the close tag when it is disposed. For example:

您将需要实现一个实现IDisposable的Section类。它必须在构造时为部分呈现开放标记，并在处理时呈现关闭标记。例如：

public class MySection : IDisposable {
    protected HtmlHelper _helper;

    public MySection(HtmlHelper helper, string className, string title) {
        _helper = helper;
        _helper.ViewContext.Writer.Write(
            "
"
        );
    }

    public void Dispose() {
        _helper.ViewContext.Writer.Write("
");
    }
}

Now that the type is available, you can extend the HtmlHelper.

现在该类型可用，您可以扩展HtmlHelper。

public static MySection BeginSection(this HtmlHelper self, string className, string title) {
    return new MySection(self, className, title);
}

4  

Here is a little util I wrote to do this. It is a little more generic so you can use it for any tag and with any attributes. It is setup as an extension method on HtmlHelper so you can use it right from within Razor as well as from within code.

这是我写的一个小工具来做这件事。它更通用，因此您可以将它用于任何标记和任何属性。它被设置为HtmlHelper上的扩展方法，因此您可以在Razor内部以及在代码内使用它。

public static class WrapUtil
{
    public static IDisposable BeginWrap(this HtmlHelper helper, string tag, object htmlAttributes)
    {
        var builder = new TagBuilder(tag);
        var attrs = GetAttributes(htmlAttributes);
        if (attrs != null)
        {
            builder.MergeAttributes(attrs);
        }
        helper.ViewContext.Writer.Write(builder.ToString(TagRenderMode.StartTag));

        return new WrapSection(helper, builder);
    }

    private static IDictionary GetAttributes(object htmlAttributes)
    {
        if (htmlAttributes == null)
        {
            return null;
        }
        var dict = htmlAttributes as IDictionary;
        if (dict != null)
        {
            return dict;
        }
        return HtmlHelper.AnonymousObjectToHtmlAttributes(htmlAttributes);
    }

    private class WrapSection : IDisposable
    {
        private readonly HtmlHelper _Helper;
        private readonly TagBuilder _Tag;

        public WrapSection(HtmlHelper helper, TagBuilder tag)
        {
            _Helper = helper;
            _Tag = tag;
        }

        public void Dispose()
        {
            _Helper.ViewContext.Writer.Write(_Tag.ToString(TagRenderMode.EndTag));
        }
    }
}