private void FindAddressButton_Click(object sender, RoutedEventArgs e)
{
_locatorTask = new Locator("http://tasks.arcgisonline.com/ArcGIS/rest/services/Locators/TA_Address_NA/GeocodeServer");
_locatorTask.AddressToLocationsCompleted += LocatorTask_AddressToLocationsCompleted;
_locatorTask.Failed += LocatorTask_Failed;
AddressToLocationsParameters addressParams = new AddressToLocationsParameters()
{
OutSpatialReference = MyMap.SpatialReference
};
Dictionary<string, string> address = addressParams.Address;
if (!string.IsNullOrEmpty(City.Text))
address.Add("City", City.Text);
if (!string.IsNullOrEmpty(State.Text))
address.Add("State", State.Text);
_locatorTask.AddressToLocationsAsync(addressParams);
}