如何将 ASP.Net MVC 5 ExecuteResult 转换为 ASP.Net Core ExecuteResultAsync

Question

我正在将我的一个 Asp.Net MVC 5 项目迁移到 Asp.Net Core。我有一个自定义 ActionResult，如果请求是 ajax 请求，它将视图呈现为部分视图，如果请求是正常请求，则将视图呈现为带有布局的普通视图。我在将旧的 ExecuteResult 转换为新的 ExecuteResultAsync 时遇到问题。

这是我的旧代码：

public override void ExecuteResult(ControllerContext context)
    {
        context.HttpContext.Response.Buffer = true;
        context.Controller.ViewData.Model = Model;

        using (var sw = new StringWriter())
        {
            var request = context.RequestContext.HttpContext.Request;

            if (string.IsNullOrEmpty(ViewName))
            {
                ViewName = request.RequestContext.RouteData.GetRequiredString("action");
            }

            var viewResult = request.IsAjaxRequest()
                ? ViewEngines.Engines.FindPartialView(context, ViewName)
                : ViewEngines.Engines.FindView(context, ViewName, "_Layout");

            var viewContext = new ViewContext(context, viewResult.View, context.Controller.ViewData, context.Controller.TempData, sw);
            viewResult.View.Render(viewContext, sw);
            context.HttpContext.Response.Write(sw.GetStringBuilder().ToString());
        }
    }

这是我的半转换代码：

public override async Task ExecuteResultAsync(ActionContext context)
    {
        context.HttpContext.Response.Buffer = true; //broken
        context.HttpContext.Controller.ViewData.Model = Model; //broken

        using (var sw = new StringWriter())
        {
            var request = context.HttpContext.Request;

            if (string.IsNullOrEmpty(ViewName))
                ViewName = context.ActionDescriptor.Name;

            var engine = context.HttpContext.RequestServices.GetService(typeof(ICompositeViewEngine)) as ICompositeViewEngine;

            var viewResult = request.Headers["X-Requested-With"] == "XMLHttpRequest"
                ? engine.FindPartialView(context, ViewName)
                : engine.FindView(context, ViewName);

            var viewContext = new ViewContext(context, viewResult.View, context.Controller.ViewData, context.Controller.TempData, sw, new HtmlHelperOptions()); //broken
            await viewResult.View.RenderAsync(viewContext);
            await context.HttpContext.Response.WriteAsync(sw.GetStringBuilder().ToString());
        }
    }

我的主要问题是 ControllerContext -> ActionContext 迁移。请帮我将 ControllerContext 转换为 ActionContext。非常感谢！

Answer 1

嗯，将一些东西放在一起以快速安装 RC2 位。随意改进它：

public override async Task ExecuteResultAsync(ActionContext context)
{
    var request = context.HttpContext.Request;

    if (string.IsNullOrEmpty(ViewName))
    {
        ViewName = context.ActionDescriptor.Name;
    }

    var engine = context.HttpContext.RequestServices.GetService(typeof(ICompositeViewEngine)) as ICompositeViewEngine;

    var viewResult = engine.FindView(context, ViewName, isMainPage: request.Headers["X-Requested-With"] != "XMLHttpRequest");
    var tempDataProvider = context.HttpContext.RequestServices.GetService(typeof(ITempDataProvider)) as ITempDataProvider;
    var modelMetaDataProvider = context.HttpContext.RequestServices.GetService(typeof(IModelMetadataProvider)) as IModelMetadataProvider;

    using (var writer = new HttpResponseStreamWriter(context.HttpContext.Response.Body, Encoding.UTF8))
    {
        var tempData = new TempDataDictionary(context.HttpContext, tempDataProvider);
        var viewData = new ViewDataDictionary(modelMetaDataProvider, context.ModelState)
        {
            Model = Model
        };
        var viewContext = new ViewContext(
            context,
            viewResult.View,
            viewData,
            tempData,
            writer,
            new HtmlHelperOptions());

        await viewResult.View.RenderAsync(viewContext);
    }
}