The problem is that the dataset is null when I load the brutile layer.
How I can change the code from the MapFrameProjectionHelper.cs
My sugestion:
//parse the projection
ProjectionInfo newProjection = ProjectionInfo.FromEsriString(newProjEsriString);
foreach (IMapLayer layer in mapFrame.GetAllLayers())
{
if (layer.CanReproject)
{
layer.Reproject(newProjection);
}
}