Testing of variable content

Question

Using ASP.Net MVC and Angularjs I tested the contents of a view thus:

$scope.estado.ldRedeBasica =  @(Model.ldRedeBasica == null ? "[]" : Html.Raw(Model.ldRedeBasica));

Only it returned the following error:

Compiler Error Message: CS0173: The conditional expression type cannot be determined because there is no implicit conversion between 'string' and 'System.Web.Ihtmlstring'

The interesting thing is that in another part of the code works:

$scope.ViewBag.Impostos = @(ViewBag.Impostos == null ? "[]" : Html.Raw(ViewBag.Impostos));

How to get around this problem?

Answer 1

Do so:

$scope.estado.ldRedeBasica =  @(Model.ldRedeBasica == null
                                ? new MvcHtmlString("[]") // ou poderia ser `Html.Raw("[]")`
                                : Html.Raw(Model.ldRedeBasica));

    ^{Documentation of Mvchtmlstring}

The error occurs because Html.Raw does not return string, but rather an implementation of the kind IHtmlString.

Imagine the situation:

var x = (condicao == true) ? "string" : 32784;

What kind of x?... impossible to say. The error you have is of the same kind as above.

To be able to determine the type of a condition using ternary operator, it is necessary that one of the expressions is convertible to the type of the other expression... which is not the case.

• nor of string for IHtmlString
• nor of IHtmlString for string

Now, to know why the other code works, then it will take a deeper investigation... not being possible to say just with what was put.