1. 两者都可以输出一个Partial视图,区别如下
2者相关源码如下:

public static class PartialExtensions { public static MvcHtmlString Partial(this HtmlHelper htmlHelper, string partialViewName) { return Partial(htmlHelper, partialViewName, null /* model */, htmlHelper.ViewData); } public static MvcHtmlString Partial(this HtmlHelper htmlHelper, string partialViewName, ViewDataDictionary viewData) { return Partial(htmlHelper, partialViewName, null /* model */, viewData); } public static MvcHtmlString Partial(this HtmlHelper htmlHelper, string partialViewName, object model) { return Partial(htmlHelper, partialViewName, model, htmlHelper.ViewData); } public static MvcHtmlString Partial(this HtmlHelper htmlHelper, string partialViewName, object model, ViewDataDictionary viewData) { using (StringWriter writer = new StringWriter(CultureInfo.CurrentCulture)) { htmlHelper.RenderPartialInternal(partialViewName, viewData, model, writer, ViewEngines.Engines); return MvcHtmlString.Create(writer.ToString()); } } }

public static class RenderPartialExtensions { // Renders the partial view with the parent's view data and model public static void RenderPartial(this HtmlHelper htmlHelper, string partialViewName) { htmlHelper.RenderPartialInternal(partialViewName, htmlHelper.ViewData, null /* model */, htmlHelper.ViewContext.Writer, ViewEngines.Engines); } // Renders the partial view with the given view data and, implicitly, the given view data's model public static void RenderPartial(this HtmlHelper htmlHelper, string partialViewName, ViewDataDictionary viewData) { htmlHelper.RenderPartialInternal(partialViewName, viewData, null /* model */, htmlHelper.ViewContext.Writer, ViewEngines.Engines); } // Renders the partial view with an empty view data and the given model public static void RenderPartial(this HtmlHelper htmlHelper, string partialViewName, object model) { htmlHelper.RenderPartialInternal(partialViewName, htmlHelper.ViewData, model, htmlHelper.ViewContext.Writer, ViewEngines.Engines); } // Renders the partial view with a copy of the given view data plus the given model public static void RenderPartial(this HtmlHelper htmlHelper, string partialViewName, object model, ViewDataDictionary viewData) { htmlHelper.RenderPartialInternal(partialViewName, viewData, model, htmlHelper.ViewContext.Writer, ViewEngines.Engines); } }
(1)Partial有返回值(MvcHtmlString),RenderPartial没有返回值(Void).
(2)Partial输出到临时变量StringWriter, RenderPartial输出到HtmlHelper.ViewContext.Writer上(即直接输出到Response)。
public static MvcHtmlString Partial(this HtmlHelper htmlHelper, string partialViewName, object model, ViewDataDictionary viewData) { using (StringWriter writer = new StringWriter(CultureInfo.CurrentCulture)) { htmlHelper.RenderPartialInternal(partialViewName, viewData, model, writer, ViewEngines.Engines); return MvcHtmlString.Create(writer.ToString()); } }
public static void RenderPartial(this HtmlHelper htmlHelper, string partialViewName, object model, ViewDataDictionary viewData) { htmlHelper.RenderPartialInternal(partialViewName, viewData, model, htmlHelper.ViewContext.Writer, ViewEngines.Engines); }
2. 在Razor视图中的使用方式
@Html.Partial("PartialViewName")
@{ Html.RenderPartial("PartialViewName"); }
3.参考网址
http://blog.csdn.net/fer_ba/article/details/7669033
4.简单Demo