Question

I have a method which takes (object value) and convert it to string with some tricky rules.

One of those rules is related to when value is IEnumerable. In this case i need to process each item in enum:

public string Convert(object value)
{
    var valuetype = value.GetType();
    if (valuetype.GetInterface("IList") != null)
    {
        var e = (IEnumerable<object>) value;
        return e.Count() == 0 ? 
            "" : 
            e.Select(o=>Convert(o)).Aggregate("", (c, s) => c+s);
    }
}

Of course, if value is List<string>, for example, line

var e = (IEnumerable<object>) value;

throw an Exception

Unable to cast object of type 'System.Collections.Generic.List`1[System.String]' to type 'System.Collections.Generic.IEnumerable`1[System.Object]'.

Any ideas, how can I get rid of it?

Answer 1

Something like

var e = ((IEnumerable) value).Cast<object>()

However I think this may fit the bill:

    public static string Convert(object value)
    {
        if (value is string) 
            return value.ToString();

        var data = value as IEnumerable;
        if (data == null)
            return string.Empty; // I think you missed this one

        var e = data.Cast<object>();
        return e.Count() == 0 ?
                string.Empty :
                e.Select(o => Convert(o)).Aggregate("", (c, s) => c + s);

    }