void Layers_LayersInitialized(object sender, EventArgs args)
{
ESRI.ArcGIS.Client.Tasks.Query query = new ESRI.ArcGIS.Client.Tasks.Query()
{
OutSpatialReference = MyMap.SpatialReference,
ReturnGeometry = true
};
query.OutFields.Add("STATE_NAME");
query.Where = "STATE_NAME IN ('Alaska', 'Hawaii', 'Washington', 'Oregon', 'Arizona', 'Nevada', 'Idaho', 'Montana', 'Utah', 'Wyoming', 'Colorado', 'New Mexico')";
QueryTask myQueryTask = new QueryTask("http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Demographics/ESRI_Census_USA/MapServer/5");
myQueryTask.ExecuteCompleted += myQueryTask_ExecuteCompleted;
myQueryTask.ExecuteAsync(query);
}