Question

I am trying the following code inside an ASP MVC Razor file:

       var topic = ViewData["TopicID"];
        var mustBeReplaced = string.Empty;
        var topicValue = Model.Topic;
        var replaceResult = string.Empty;
        if (topic.Contains(topicValue)) {
            mustBeReplaced = "value=\"" + topicValue + "\"";
            replaceResult = mustBeReplaced + " selected=\"selected\"";
            topic = topic.Replace(mustBeReplaced, replaceResult);             
        }

But I get an error message:

object’ does not contain a definition for ‘Contains’ and the best extension method overload

Answer 1

var topic = ViewData["TopicID"];

Returns object. You need to cast to string.