Zoom

1、zoom to layer

            ILayer layer = (ILayer)m_mapControl.CustomProperty;
            m_mapControl.Extent = layer.AreaOfInterest;
            m_mapControl.Refresh(esriViewDrawPhase .esriViewGeography,layer,null);

2、zoom resolution

            IMap pMap = axMapControl1 .Map;
            IRasterLayer pRasterLayer = pMap.get_Layer( 0 ) as IRasterLayer;
            int controlWidth = axMapControl1.Width;
            double controlW = Convert.ToDouble( controlWidth );
            pMap.MapScale = (controlW / pRasterLayer.ColumnCount * pMap.MapScale);
            IActiveView pActiveView = axMapControl1.ActiveView;
            pActiveView.PartialRefresh(esriViewDrawPhase.esriViewGeography, null, null);