Question

I have the following Controller Action:

public ActionResult MyAction(...)
{
    ActionResult result = View("MyView", new MyModel());

    var fruit = TempData["Fruit"];
    // Do something with the fruit

    return result;
}

and this MyView.cshtml

@model MyModel
@{ 
    TempData["Fruit"] = "Mango";
}

When I put a breakpoint in the View where TempData["Fruit"] is set, it isn’t called before the “return result” in the Action. The Razor rendering seems to be delayed.

How can I force the View to be rendered on return from the result = View(..) call?

Note: Don’t worry about this simplistic example. We have a real use case where a solution to this would really be needed but I didn’t want to burden the question any further.

Answer 1

The View isn’t rendered until after the Action is complete. You can call result.ExecuteResult(ControllerContext) to force the early execution of the ActionResult inside the action like this:

    ActionResult result = View("Details", new PageModel(page));
    result.ExecuteResult(ControllerContext);

But you will then have a problem because the ActionResult will be executed again when the action returns the result, so you will have to cancel that second execution.

You can do this like so:

    protected override void OnResultExecuting(ResultExecutingContext filterContext)
    {
        if (cancelTheResult)
        {
            filterContext.Cancel = true;
        }
        base.OnResultExecuting(filterContext);
    }

This all does seem like a bit of a hack, but in some scenarios it seems necessary. For instance if a child action needs to tell the top level action to carry out a redirect, we won’t know the redirect is required until the child action completes, but the child action won’t be completed until too late. This is the only workaround I’ve been able to find.