private void DisplayMap_Load(object sender, EventArgs e)
        {
            winformsMap1.MapUnit = GeographyUnit.DecimalDegree;
            winformsMap1.BackgroundOverlay.BackgroundBrush = new GeoSolidBrush(GeoColor.GeographicColors.ShallowOcean);

            ShapeFileFeatureLayer shpLayer = new ShapeFileFeatureLayer(@"..\..\sampledata\data\countries02.shp");
            shpLayer.ZoomLevelSet.ZoomLevel01.ApplyUntilZoomLevel = ApplyUntilZoomLevel.Level20;
            shpLayer.ZoomLevelSet.ZoomLevel01.DefaultAreaStyle = AreaStyles.Country1;
            
            LayerOverlay ov = new LayerOverlay();
            ov.Layers.Add(shpLayer);

            winformsMap1.Overlays.Add(ov);
            winformsMap1.ZoomLevelSnapping = ZoomLevelSnappingMode.None;
            winformsMap1.CurrentExtent = new RectangleShape(-139.2, 92.4, 120.9, -93.2);
            winformsMap1.Refresh();
        }

        double percent = 0.5;

        private void button1_Click(object sender, EventArgs e)
        {
            winformsMap1.ZoomToScale(winformsMap1.CurrentScale * (1 + percent));
            winformsMap1.Refresh();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            winformsMap1.ZoomToScale(winformsMap1.CurrentScale / (1 + percent));
            winformsMap1.Refresh();
        }

        private WinformsMap winformsMap1;
        private Button button1;
        private Button button2;