/// <summary>
/// 获取地图中所有的栅格图层
/// </summary>
/// <param name="pMap"></param>
/// <param name="puid"></param>
/// <returns></returns>
static public List<IRasterLayer> GetRasterLayers(IMap pMap)
{
//只读取IRasterLayer
UID puid = new UIDClass();
//uid 值:
//{6CA416B1 - E160 - 11D2 - 9F4E - 00C04F6BC78E} IDataLayer
//{40A9E885 - 5533 - 11d0 - 98BE - 00805F7CED21} IFeatureLayer
//{E156D7E5 - 22AF - 11D3 - 9F99 - 00C04F6BC78E} IGeoFeatureLayer
//{34B2EF81 - F4AC - 11D1 - A245 - 080009B6F22B} IGraphicsLayer
//{5CEAE408 - 4C0A - 437F - 9DB3 - 054D83919850} IFDOGraphicsLayer
//{0C22A4C7 - DAFD - 11D2 - 9F46 - 00C04F6BC78E} ICoverageAnnotationLayer
//{EDAD6644 - 1810 - 11D1 - 86AE - 0000F8751720} IGr