unpacking viewdata in foreach statement

So I packed some query results in a viewdata statement.

I can verify the correct number of results are put into the viewdata object in the view with this directive:

@foreach (var action in (List<LemonadeTrader.Models.Message>)ViewDa开发者_StackOverflow中文版ta["messages"]) {

When I try to display the results:

@Html.DisplayFor( (LemonTrader.Models.Message)action.msg)   // action.msg should be of type string

It says it couldn't convert string to LemonTrader.Models.Lemon.

When I cast it as:

@Html.DisplayFor( (string)action.acidity)

It says:

The type arguments for method 'System.Web.Mvc.Html.DisplayExtensions.DisplayFor(System.Web.Mvc.‌ ​HtmlHelper, System.Linq.Expressions.Expression>)' cannot be inferred from the usage. Try specifying the type arguments explicitly.

Not casting it at all doesn't work either.

How do I cast the result?

DisplayFor/EditorFor works with strongly typed views and view models. It takes as first argument a lambda expression which represents the property on your view model you are trying to display/edit. So throw this ViewData into the dustbin (which is where it belongs) and use view models and strongly typed views.

So instead of the following horror:

@foreach (var action in (List<LemonadeTrader.Models.Message>)ViewData["messages"]) {

You will have a view model with a Messages property of the correct type:

@foreach (var action in Model.Messages) {

Or even better (why writing foreach loops when dislpay/editor templates already do this):

@Html.DisplayFor(x => x.Messages)

This way you get many bonuses:

• your code will work
• you get intellisense
• no more brittle magic strings
• instead of resembling to some spaghetti code your views become far more readable
• ...

I think this is just a syntax error, because the DisplayFor expects a Func that gets your model as input. Try this: @Html.DisplayFor(m => (string)action.acidity)

This worked:

@foreach (var action in (List<LemonTrader.Models.Message>)ViewData["lemons"]) {
    <tr>
        <td>
            @Html.Encode( action.acidity)