自定义ViewHelper来简化Asp.net MVC view

日期：08-16 来源：中国设计秀作者：cnwebshow.com

让我们开始做到这一点，首先创建一个实现IViewObject接口的类，命名为HtmlFieldSet类并继承与AbstractHtmlViewObject，整个类的代码附下：

public class HtmlFieldset : AbstractHtmlViewObject
{
    private readonly string mTitle;

    public HtmlFieldset(
        ViewRequestContext requestContext, string name,
        string title, object attributes)
        : base(requestContext, name)
    {
        mTitle = title;
        Attributes = attributes;
    }

    private TagBuilder FieldsetTag { get; set; }

    private TagBuilder OlTag { get; set; }

    public override void StartView()
    {
        HttpResponseBase httpResponse = RequestContext.HttpResponse;

        FieldsetTag = new TagBuilder("fieldset");

        // apply any Attributes passed in
        if (Attributes != null)
        {
            FieldsetTag.MergeAttributes(new RouteValueDictionary(Attributes));
        }
        // The Name property should override any passed into the Attributes
        FieldsetTag.MergeAttribute("name", Name, true);

        httpResponse.Write(FieldsetTag.ToString(TagRenderMode.StartTag));

        if (!string.IsNullOrEmpty(mTitle))
        {
            TagBuilder legendTag = new TagBuilder("legend");
            legendTag.SetInnerText(mTitle);
            httpResponse.Write(legendTag.ToString(TagRenderMode.Normal));
        }

        OlTag = new TagBuilder("ol");
        httpResponse.Write(OlTag.ToString(TagRenderMode.StartTag));
    }

    public override void EndView()
    {
        HttpResponseBase httpResponse = RequestContext.HttpResponse;

        httpResponse.Write(OlTag.ToString(TagRenderMode.EndTag));
        httpResponse.Write(FieldsetTag.ToString(TagRenderMode.EndTag));
    }
} 这个类的实现和其它的view对象没什么不同，除了EndView方法，在这里我们需要EndView方法来生成必须的结束标记。当然我们也可以使用EndView来生成任何需要的HTML,在这里我们仅是用它生成结束标记。