【MVC】擴充HtmlHelper

• 第一個範例，讓ActionLink可以放HTML標籤進去
• 首先我先在專案中建立一個資料夾，並且在裡面新增一個類別檔案

   [![](http://2.bp.blogspot.com/-NBhxVa8AExI/UYoHecX2TrI/AAAAAAAADIE/G9Hvt_r7t_4/s1600/%E6%9C%AA%E5%91%BD%E5%90%8D.png)](http://2.bp.blogspot.com/-NBhxVa8AExI/UYoHecX2TrI/AAAAAAAADIE/G9Hvt_r7t_4/s1600/%E6%9C%AA%E5%91%BD%E5%90%8D.png)*   ```csharp
  

  //將命名空間改成System.Web.Mvc.Html，使用前不用修改~/Views/Web.config
  namespace System.Web.Mvc.Html
  {
  public static class MyHtmlHelperExtensions
  {

    public static MvcHtmlString InsertHtmlTagActionLink(this AjaxHelper ajaxHelper,string linkText ,string actionName, string controllerName, AjaxOptions ajaxOptions)        {
        var lnk = ajaxHelper.ActionLink("[replaceme]", actionName, controllerName, ajaxOptions);
        return MvcHtmlString.Create(lnk.ToString().Replace("[replaceme]", linkText));
    }
  

  }

*   使用方式如下      ```csharp
@Ajax.InsertHtmlTagActionLink("<i class='icon-file'></i>"+@childFunction.funname, action, controller, new AjaxOptions { UpdateTargetId="BackStageBody" });
     

• 第二個範例，將TextBoxFor固定塞入一個data-content的html屬性，並將值給這個屬性
• ```csharp
  public static MvcHtmlString TextBoxFor_WithOriginData<TModel, TProp>(this HtmlHelper htmlHelper, Expression<Func<TModel, TProp>> expression,object HtmlAttributes = null){
  //透過AnonymousObjectToHtmlAttributes將HtmlAttribute讀取出來
  var attrs = HtmlHelper.AnonymousObjectToHtmlAttributes(HtmlAttributes);
  //將expression的值抓出來放到data-content這個屬性中
  attrs.Add(“data-content”,ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData).Model);
  var txtBoxFor = htmlHelper.TextBoxFor(expression, attrs);
  return MvcHtmlString.Create(txtBoxFor.ToString());
  }

*   **第三個範例，加入Img這個Tag**
*   ```csharp
public static MvcHtmlString ImageFor_WithOriginData<TModel, TProp>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProp>> expression, object HtmlAttributes = null){
    string value = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData).Model == null ? "" : ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData).Model.ToString();
    //屬性的值
    string propname = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData).PropertyName;

        //透過AnonymousObjectToHtmlAttributes將HtmlAttribute讀取出來
    var attrs = HtmlHelper.AnonymousObjectToHtmlAttributes(HtmlAttributes);
    attrs.Add("data-content", value);
    attrs.Add("src", value);
    attrs.Add("name", propname);

        var img = new TagBuilder("img");
    img.MergeAttributes(attrs);
    return MvcHtmlString.Create(img.ToString(TagRenderMode.SelfClosing));
}