Question

I have written and used some class extensions succesfully. However, although I can write the following one, I can’t figure out how to call it. This particular one is intended to convert an attribute style key-value pair list to a string.

public static class Extensions
{
    public static string AttributesToString<T, T1>(this Dictionary<T, T1> dict)
    {
        StringBuilder sb = new StringBuilder();

        foreach (KeyValuePair<T, T1> kv in dict)
        {
            sb.Append(" " + kv.Key + "=\"" + kv.Value + "\"");
        }

        return sb.ToString();
    }
}

The following doesn’t work:

Dictionary<string, string> dict = new Dictionary<string, string>();

dict.AttributesToString() // error

How can I call this extension?

Answer 1

You’ve got some kind of build or scope error. This works perfectly. Are your extension methods in another assembly or namespace?

namespace ConsoleApplication3
{
    class Program
    {
        static void Main(string[] args)
        {
            Dictionary<string, string> dict = new Dictionary<string, string>();
            dict.AttributesToString();
        }
    }

    public static class Extensions
    {
        public static string AttributesToString<T, T1>(this Dictionary<T, T1> dict)
        {
            StringBuilder sb = new StringBuilder();

            foreach (KeyValuePair<T, T1> kv in dict)
            {
                sb.Append(" " + kv.Key + "=\"" + kv.Value + "\"");
            }

            return sb.ToString();
        }
    }
}