c# - Passing data from Partial View to its parent View

Question

If I have a View and a Partial View, is there any way that I can pass data from the Partial View to the parent?

So if I have View.cshtml:

<div id="@someDataFromPartialSomehow">
    @Html.Partial("_PartialView")
</div>

And _PartialView.cshtml:

@{ someDataFromPartialSomehow = "some-data" }

<div>
    Some content
</div>

How would I go about implementing something like this?

I tried to use ViewBag.SomeDataFromPartialSomehow, but this just results in null in the Parent.

---

An attempt

To try get around the problem of data being generated before being called I tried this:

View.cshtml:

@{ var result = Html.Partial("_PartialView"); }

<div id="@ViewData["Stuff"]">
    @result
<div>

_PartialView.cshtml:

@{ ViewData["Stuff"] = "foo"; }

<div>
    Content
</div>

But the call to @ViewDate["Stuff"] still renders nothing unfortunately.

Answer 1

You could share state between views using the HttpContext.

@{
    this.ViewContext.HttpContext.Items["Stuff"] = "some-data";
}

and then:

@{ var result = Html.Partial("_PartialView"); }

<div id="@this.ViewContext.HttpContext.Items["Stuff"]">
    @result
<div>

Except that the example you have shown in your question:

<div id="@someDataFromPartialSomehow">
    @Html.Partial("_PartialView")
</div>

you are attempting to use the someDataFromPartialSomehow even BEFORE invoking the partial view which obviously is impossible.

Also bear in mind that what you are trying to achieve is bad design. If a partial view can only work in the context of some specific parent, then you might need to rethink your separation of views. Partial views is something that must be INDEPENDENT and REUSABLE, no matter in which context it is being placed. If it assumes things about the hosting parent then there's a serious design problem here.