Custom ActionResult equivalent Model for all PartialViews

Question

I created following custom ActionResult which returns multiple partial views.

public class MultiplePartialViewsResult : ActionResult
{
    private const string Separator = "-";
    private PartialViewResult[] _partialViews;

    public MultiplePartialViewsResult(params PartialViewResult[] partialViews)
    {
        _partialViews = partialViews;
    }

    public override void ExecuteResult(ControllerContext context)
    {
        foreach (var partialView in _partialViews)
        {
            partialView.ExecuteResult(context);
            context.HttpContext.Response.Output.Write(Separator);
        }
    }
}

And then I use it as follows:

return new MultiplePartialViewsResult(
             PartialView("~/Views/RowSumView.cshtml", new List<double>() { 1.0 }),
             PartialView("~/Views/ColumnSumView.cshtml", new List<double>() { 2.0 }));

But if I place breakpoint in MultiplePartialViewsResult's constructor I see that model in both cases equals 2.0. It overrides all models with the last model specified in a array.

Try to create couple PartialViews in method and assign it to variable. Then you will notice they all share equivalent model.

Answer 1

You can initialize the MultiplePartialViewsResult object in the following manner with new own ViewData / ViewData.Model instances (works fine for me):

return new MultiplePartialViewsResult(
    //PartialView("~/Views/RowSumView.cshtml", new List<double>() { 1.0 }),
    //PartialView("~/Views/ColumnSumView.cshtml", new List<double>() { 2.0 })
    new PartialViewResult() { ViewName = "~/Views/RowSumView.cshtml", ViewData = new ViewDataDictionary() { Model = new List<double>() { 1.0 } } },
    new PartialViewResult() { ViewName = "~/Views/ColumnSumView.cshtml", ViewData = new ViewDataDictionary() { Model = new List<double>() { 2.0 } } }
);

Custom Action Result:

public class MultiplePartialViewsResult : ActionResult {
    private const string Separator = "-";
    private PartialViewResult[] _partialViews;

    public MultiplePartialViewsResult(params PartialViewResult[] partialViews) {
        _partialViews = partialViews;
    }

    public override void ExecuteResult(ControllerContext context) {
        foreach(var partialView in _partialViews) {
            partialView.ExecuteResult(context);
            context.HttpContext.Response.Output.Write(Separator);
        }
    }
}

Controller:

public ActionResult Index() {
    return View();
}
public ActionResult FakeAction() {
    return new MultiplePartialViewsResult(
        //PartialView("~/Views/RowSumView.cshtml", new List<double>() { 1.0 }),
        //PartialView("~/Views/ColumnSumView.cshtml", new List<double>() { 2.0 })
        new PartialViewResult() { ViewName = "~/Views/RowSumView.cshtml", ViewData = new ViewDataDictionary() { Model = new List<double>() { 1.0 } } },
        new PartialViewResult() { ViewName = "~/Views/ColumnSumView.cshtml", ViewData = new ViewDataDictionary() { Model = new List<double>() { 2.0 } } }
    );
}

Views:

Index:

@Html.Action("FakeAction")

ColumnSumView.cshtml / RowSumView.cshtml:

@model List<double>
<ul>
    @foreach(double item in Model) {
        <li>@item</li>
    }
</ul>