title: Delphi TDictionary iteration
body: <p>I have a function where I store some key- value pairs and when I iterate them I get this error twice: [dcc32 Error] App.pas(137): E2149 Class does not have a default property.
  Here is part of my code:</p>
  
  <pre><code>function BuildString: string;
  var
    i: Integer;
    requestContent: TDictionary&lt;string, string&gt;;
    request: TStringBuilder;
  begin
    requestContent := TDictionary&lt;string, string&gt;.Create();
  
    try
      // add some key-value pairs
      request :=  TStringBuilder.Create;
      try
        for i := 0 to requestContent.Count - 1 do
        begin
          // here I get the errors
          request.Append(requestContent.Keys[i] + '=' +
            TIdURI.URLEncode(requestContent.Values[i]) + '&amp;');
        end;
  
        Result := request.ToString;
        Result := Result.Substring(0, Result.Length - 1); //remove the last '&amp;'
      finally
        request.Free;
      end; 
    finally
      requestContent.Free;
    end;
  end;
  </code></pre>
  
  <p>I need to collect the information from each item in the dictionary.  How can I fix it?   </p>