Possible to create an implicit cast for an anonymous type to a dictionary?
- by Ralph
I wrote a method like this:
using AttrDict = System.Collections.Generic.Dictionary<string, object>;
using IAttrDict = System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<string, object>>;
static string HtmlTag(string tagName, string content = null, IAttrDict attrs = null)
{
var sb = new StringBuilder("<");
sb.Append(tagName);
if(attrs != null)
foreach (var attr in attrs)
sb.AppendFormat(" {0}=\"{1}\"", attr.Key, attr.Value.ToString().EscapeQuotes());
if (content != null) sb.AppendFormat(">{0}</{1}>", content, tagName);
else sb.Append(" />");
return sb.ToString();
}
Which you can call like
HtmlTag("div", "hello world", new AttrDict{{"class","green"}});
Not too bad. But what if I wanted to allow users to pass an anonymous type in place of the dict? Like
HtmlTag("div", "hello world", new {@class="green"});
Even better! I could write the overload easily, but the problem is I'm going to have about 50 functions like this, I don't want to overload each one of them. I was hoping I could just write an implicit cast to do the work for me...
public class AttrDict : Dictionary<string, object>
{
public static implicit operator AttrDict(object obj)
{
// conversion from anonymous type to AttrDict here
}
}
But C# simply won't allow it:
user-defined conversions to or from a base class are not allowed
So what can I do?
