C# Webservice

Question

I have got my Webservice it should read Data from a Database and Transfer it to My WPF Application but it doesn't display any data.

IService.cs
namespace WcfService2
{

    [ServiceContract]
    public interface IService1
    {

        [OperationContract]
        string GetData(int value);

        [OperationContract]
        CompositeType GetDataUsingDataContract(CompositeType composite);

        // TODO: Hier Dienstvorgänge hinzufügen
        [OperationContract]
        WeatherContract GetWeatherData(WeatherContract weather);
    }



    [DataContract]
    public class CompositeType
    {
        bool boolValue = true;
        string stringValue = "Hello ";

        [DataMember]
        public bool BoolValue
        {
            get { return boolValue; }
            set { boolValue = value; }
        }

        [DataMember]
        public string StringValue
        {
            get { return stringValue; }
            set { stringValue = value; }
        }
    }

    [DataContract]
    public class WeatherContract
    {
        [DataMember]
        public DateTime start
        {
            set; get;
        }
        [DataMember]
        public DateTime end
        {
            set; get;
        }

        [DataMember]
        public List<WeatherDataDTO> weatherData
        {
            set; get;
        }

    }

    public partial class WeatherDataDTO
    {
        public int Id { get; set; }
        public Nullable<System.DateTime> Datum { get; set; }
        public Nullable<System.TimeSpan> Zeit { get; set; }
        public Nullable<double> Temperatur { get; set; }
        public Nullable<int> Luftdruck { get; set; }
        public Nullable<int> Regen { get; set; }
        public Nullable<double> Wind { get; set; }
        public Nullable<int> Richtung { get; set; }
        public Nullable<int> Feuchtigkeit { get; set; }
    }
}

Service.svc

public class Service1 : IService1
{
public string GetData(int value)
{
return string.Format("You entered: {0}", value);
}

    public CompositeType GetDataUsingDataContract(CompositeType composite)
    {
        if (composite == null)
        {
            throw new ArgumentNullException("composite");
        }
        if (composite.BoolValue)
        {
            composite.StringValue += "Suffix";
        }
        return composite;
    }
    public WeatherContract GetWeatherData(WeatherContract weather)
    {
        //WeatherDataEntities db = new WeatherDataEntities();

        WeatherDataDAO.getWeatherData(weather.start,weather.end);

        List<WeatherData> weatherDatas = new List<WeatherData>();
        List<WeatherDataDTO> dtos = new List<WeatherDataDTO>();

        foreach(WeatherData data in weatherDatas)
        {
            WeatherDataDTO weatherDataDTO = new WeatherDataDTO();

            weatherDataDTO.Id = data.Id;
            weatherDataDTO.Datum = data.Datum.Value;
            weatherDataDTO.Zeit = data.Zeit.Value;
            weatherDataDTO.Temperatur = data.Temperatur.Value;
            weatherDataDTO.Luftdruck = data.Luftdruck.Value;
            weatherDataDTO.Regen = data.Regen.Value;
            weatherDataDTO.Wind = data.Wind.Value;
            weatherDataDTO.Richtung = data.Richtung.Value;
            weatherDataDTO.Feuchtigkeit = data.Feuchtigkeit.Value;

            dtos.Add(weatherDataDTO);
        }

        weather.weatherData = dtos;

        return weather;

    }
}  

}

WeatherDataDAO

public class WeatherDataDAO
    {
        private static WeatherDataEntities weatherData = new WeatherDataEntities();

        public static List<WeatherData> getWeatherData(DateTime start, DateTime end)
        {
            var query = from weatherData in weatherData.WeatherData
                        where weatherData.Datum <= end && weatherData.Datum >= start
                        orderby weatherData.Id
                        select weatherData;

            return query.ToList();
        }
    }

My WeatherData DAO CLass in the WPF Application

class WeatherDataDAO
    {
        public static ServiceReference1.Service1Client client = new ServiceReference1.Service1Client();

        public static ServiceReference1.WeatherDataDTO[] GetWeatherDatas(DateTime begin, DateTime end, int page)
        {
            var contract = new ServiceReference1.TemperatureContract();
            contract.BeginValue = begin;
            contract.EndValue = end;
            contract.PageValue = page;


            return client.GetTemperatures(contract).WeatherDataValues;
        }

        public static List<double> GetTemperatures(DateTime begin, DateTime end, int page)
        {
            var contract = new ServiceReference1.TemperatureContract();
            contract.BeginValue = begin;
            contract.EndValue = end;
            contract.PageValue = page;

            List<double> temperatures = new List<double>();
            foreach (ServiceReference1.WeatherDataDTO weatherData in client.GetTemperatures(contract).WeatherDataValues)
                temperatures.Add(weatherData.Temperatur);

            return temperatures;
        }
    }

MAinWindows.xaml

private void getButton_Click(object sender, RoutedEventArgs e)
        {
            if (!beginDatePickewr.SelectedDate.HasValue || !endDatePicker.SelectedDate.HasValue)
                return;

            int page = 0;
            try
            {
                page = int.Parse(pageTextBox.Text);
            }
            catch (Exception)
            {

            }

            temperatreDataGrid.ItemsSource = WeatherDataDAO.GetWeatherDatas(beginDatePickewr.SelectedDate.Value, endDatePicker.SelectedDate.Value, page);
        }