Return View as String in .NET Core

Question

I found some article how to return view to string in ASP.NET, but could not covert any to be able to run it with .NET Core

public static string RenderViewToString(this Controller controller, string viewName, object model)
{
    var context = controller.ControllerContext;
    if (string.IsNullOrEmpty(viewName))
        viewName = context.RouteData.GetRequiredString("action");

    var viewData = new ViewDataDictionary(model);

    using (var sw = new StringWriter())
    {
        var viewResult = ViewEngines.Engines.FindPartialView(context, viewName);
        var viewContext = new ViewContext(context, viewResult.View, viewData, new TempDataDictionary(), sw);
        viewResult.View.Render(viewContext, sw);

        return sw.GetStringBuilder().ToString();
    }
}

which assumed to be able to call from a Controller using:

var strView = this.RenderViewToString("YourViewName", yourModel);

When I try to run the above into .NET Core I get lots of compilation errors.

I tried to convert it to work with .NET Core, but failed, can anyone help with mentioning the required using .. and the required "dependencies": { "Microsoft.AspNetCore.Mvc": "1.1.0", ... }, to be used in the project.json.

some other sample codes are here and here and here

NOTE I need the solution to get the view converted to string in .NET Core, regardless same code got converted, or another way that can do it.

Answer 1

If like me you have a number of controllers that need this, like in a reporting site, it's not really ideal to repeat this code, and even injecting or calling another service doesn't really seem right.

So I've made my own version of the above with the following differences:

• model strong-typing
• error checking when finding a view
• ability to render views as partials or pages
• asynchronus
• implemented as a controller extension

• no DI needed

  using Microsoft.AspNetCore.Mvc;
  using Microsoft.AspNetCore.Mvc.Rendering;
  using Microsoft.AspNetCore.Mvc.ViewEngines;
  using Microsoft.AspNetCore.Mvc.ViewFeatures;
  using System.IO;
  using System.Threading.Tasks;
  
  namespace CC.Web.Helpers
  {
      public static class ControllerExtensions
      {
          public static async Task<string> RenderViewAsync<TModel>(this Controller controller, string viewName, TModel model, bool partial = false)
          {
              if (string.IsNullOrEmpty(viewName))
              {
                  viewName = controller.ControllerContext.ActionDescriptor.ActionName;
              }
  
              controller.ViewData.Model = model;
  
              using (var writer = new StringWriter())
              {
                  IViewEngine viewEngine = controller.HttpContext.RequestServices.GetService(typeof(ICompositeViewEngine)) as ICompositeViewEngine;
                  ViewEngineResult viewResult = viewEngine.FindView(controller.ControllerContext, viewName, !partial);
  
                  if (viewResult.Success == false)
                  {
                      return $"A view with the name {viewName} could not be found";
                  }
  
                  ViewContext viewContext = new ViewContext(
                      controller.ControllerContext,
                      viewResult.View,
                      controller.ViewData,
                      controller.TempData,
                      writer,
                      new HtmlHelperOptions()
                  );
  
                  await viewResult.View.RenderAsync(viewContext);
  
                  return writer.GetStringBuilder().ToString();
              }
          }
      }
  }
  

Then just implement with:

viewHtml = await this.RenderViewAsync("Report", model);

Or this for a PartialView:

partialViewHtml = await this.RenderViewAsync("Report", model, true);