using ESRI.ArcGIS.Controls;
 using ESRI.ArcGIS.Carto;
 using ESRI.ArcGIS.esriSystem;
 using ESRI.ArcGIS.DataSourcesRaster;
 using ESRI.ArcGIS.SpatialAnalystTools;
 using ESRI.ArcGIS.Geodatabase;//IRaster
 using ESRI.ArcGIS.Display;//IRasterLayer

  if (DHmapcontrol.LayerCount == )//DHmapcontrol为mapcontrol控件
             {
                 MessageBox.Show("请添加栅格图层");
             }
             else 
             { 
                 string layername = DHmapcontrol.Map.Layer[].Name; MessageBox.Show(layername);//图层名称

                 IRasterLayer rasterlayer = new RasterLayerClass();
                 rasterlayer = (IRasterLayer)DHmapcontrol.Map.Layer[];
                 IRaster raster = rasterlayer.Raster;
                 IRasterProps rasterprops = (IRasterProps)raster;
                 int height = rasterprops.Height;//栅格行
                 int width = rasterprops.Width;//栅格列
                 long cont = height * width;//栅格总数
                 MessageBox.Show(Convert.ToString(cont));

             }