Mvc渲染動作/部分響應輸出

Question

雖然@Html.RenderPartial調用write並返回void ，但它仍然寫入StringWriter / StringBuilder 。 有沒有辦法直接渲染到ResponseStream ？

這可以通過自定義IViewEngine完成，它實現像PdfView這樣的渲染直接輸出到ResponseStream嗎？

加成

ViewResultBase.ExecuteResult顯示使用Response.Output構建的ViewContext ，但調試器將ViewContext.Writer顯示為StringWriter

這兩種方法都會產生StringWriter

return PartialView("view", Model)
// or
PartialView("view", Model).ExecuteResult(ControllerContext)

編輯

似乎System.Web.WebPages.WebPageBase ExecutePageHeirarchy將臨時StringWriter推送到上下文堆棧，所以我不確定是否可以繞過它

綜上所述

RenderPartial，RenderAction不直接輸出到Response.Stream，Razor Views都不會

解

這是新的WebPages / Razor渲染引擎，它將StringWriter所有內容包裝到StringBuilder 。 解決方案是更改我的頁面以使用不應用此包裝的WebFormViewEngine 。

Answer 1

以下方法說明了實現您正在尋找的結果的一種方法：

// <summary>
// An extension methods for rendering a model/view into a stream
// </summary>
// <param name="myModel">The model you are trying render to a stream</param>
// <param name="controllerBase">This will come from your executing action</param>
// <returns></returns>
        public static Stream GetStream(CustomModel myModel, ControllerBase controllerBase)
        {
            //we will return this stream
            MemoryStream stream = new MemoryStream();

            //you can add variables to the view data
            controllerBase.ViewData["ViewDataVariable1"] = true;

            //set your model
            controllerBase.ViewData.Model = myModel;

            //The example uses the UTF-8 encoding, you should change that if you are using some other encoding.
            //write to a stream
            using (StreamWriter writer = new StreamWriter(stream, Encoding.UTF8))
            {
                using (var sw = new StringWriter())
                {
                    //render the view  ~/Views/Shared/_FeedbackMessage.cshtml (can be passed in as a parameter if you want to make it super generic)
                    var viewResult = ViewEngines.Engines.FindPartialView(controllerBase.ControllerContext, "_FeedbackMessage");

                    //create a new view context
                    var viewContext = new ViewContext(controllerBase.ControllerContext, viewResult.View, controllerBase.ViewData, controllerBase.TempData, sw);

                    //Render the viewengine and let razor do its magic
                    viewResult.View.Render(viewContext, sw);    
                    viewResult.ViewEngine.ReleaseView(controllerBase.ControllerContext, viewResult.View);

                    //get StringBuilder from StringWriter sw and write into the stream writer
                    //you could simply return the StringWriter here if that is what you were interested in doing
                    writer.Write(sw.GetStringBuilder().ToString());

                    writer.Flush();

                    stream.Position = 0;
                }

            }

            //return the stream from the above process
            return stream;
        }