Arcgis Engine（ae）接口详解（7）：地图（map）操作

            IMap map = hookHelper.FocusMap;

            //跟map同一层次的activeView对象，他们都是“地图”的对象，map管理地图内容，activeView管理显示内容

            IActiveView activeView = map as IActiveView;



            //获取当前地图显示范围

            IEnvelope extent = activeView.Extent;

            //设置当前地图显示范围，相当于用代码实现缩放到某个范围

            activeView.Extent = extent;



            //获取地图全图范围

            //地图浏览功能中的全图，他的范围就是这样获取

            IEnvelope fullExtent = activeView.FullExtent;



            //获取地图比例尺，同时可同于设置比例尺

            double mapScale = map.MapScale;



            //获取和设置地图单位

            esriUnits unit = map.MapUnits;

            //获取和设置地图的显示单位

            esriUnits unit2 = map.DistanceUnits;



            //刷新地图

            activeView.Refresh();



            //屏幕长度（单位是像素）转地图实际长度

            double mapLength = MapHelper.PixelsToMapUnits(activeView, 5);



            //获取Map的所有FeatureLayer

            List<IFeatureLayer> lstFeatureLayer = MapHelper.GetAllFeatureLayerInMap(map);



            if (1 == 2)

            {

                //在Map中通过真实表名获取图层，对于sde的表名不能带用户名

                IFeatureLayer featureLayer = MapHelper.GetFeatureLayerByDatasetName(map, "roadLine");



            }



            foreach (IFeatureLayer featureLayer in lstFeatureLayer)

            {

                //图层相关说明



                //IFeatureLayer代表矢量图层，而ILayer代表图层，也是所有类型图层接口都实现了ILayer，因此IFeatureLayer可以as到ILayer

                ILayer layer = featureLayer as ILayer;



                //获取和设置图层的可视状态（就是图层树界面里图层左边的checkbox）

                bool visible = layer.Visible;

                //获取或设置图层名称

                string name = layer.Name;



                //通过图层获取featureClass，是获取featureClass的方法之一。另一种方法是通过workspace获取

                //注意IFeatureLayer和IFeatureClass是两个东西，虽然平时会都叫“图层”。IFeatureClass是指物理表，而IFeatureLayer指物理表加载到地图上形成的图层，前者更多指数据，后者只图层在地图的展示设置，如样式，标注等

                IFeatureClass featureClass = featureLayer.FeatureClass;                

            }

        public static double PixelsToMapUnits(IActiveView activeView, double pixelLength)

        {

            tagRECT tagRect = activeView.ScreenDisplay.DisplayTransformation.get_DeviceFrame();

            int width = tagRect.right - tagRect.left;



            if (width < 0.00001) return pixelLength;

            double scale = activeView.ScreenDisplay.DisplayTransformation.VisibleBounds.Width / width;



            return (pixelLength * scale);

        }

        

                public static List<IFeatureLayer> GetAllFeatureLayerInMap(IMap map)

        {

            List<IFeatureLayer> result = new List<IFeatureLayer>();



            UID uid = new UIDClass();

            uid.Value = "{40A9E885-5533-11d0-98BE-00805F7CED21}";    //FeatureLayer

            IEnumLayer enumLayer = map.get_Layers(uid, true);

            //对图层转换版本

            ILayer layer = null;

            while ((layer = enumLayer.Next()) != null)

            {

                IFeatureLayer featureLayer = layer as IFeatureLayer;

                result.Add(featureLayer);

            }



            return result;

        }

        

                public static IFeatureLayer GetFeatureLayerByDatasetName(IMap map, string tableName)

        {

            List<IFeatureLayer> lstFeatureLayer = GetAllFeatureLayerInMap(map);



            foreach (IFeatureLayer featureLayer in lstFeatureLayer)

            {

                if (featureLayer.FeatureClass != null)

                {

                    string featureClassName = FeatureClassHelper.GetDatasetNameWithOutSDEUser(featureLayer.FeatureClass as IDataset);

                    if (string.Equals(featureClassName, tableName, StringComparison.OrdinalIgnoreCase))

                    {

                        return featureLayer;

                    }

                }

            }



            return null;

        }

        

                public static string GetDatasetNameWithOutSDEUser(IDataset dataset)

        {

            if (dataset == null) return "";



            string tDatasetName = dataset.Name;

            if (tDatasetName.Contains("."))

            {

                tDatasetName = tDatasetName.Substring(tDatasetName.LastIndexOf(".") + 1);

            }



            return tDatasetName;

        }