Exemplo n.º 1
0
        private static TileProjection getTileProjection(ProjectionType projType, CoordinateExtent extent, int?minZoomLevel, int?maxZoomLevel)
        {
            // 默认投影信息
            Projection projection = new Projection(projType);
            // 瓦片投影
            TileProjection tileProjection = new TileProjection();

            tileProjection.ProjType = projType;
            if (extent == null)
            {
                extent = projection.GetDefaultCoordinateExtent();
            }
            else
            {
                extent = projection.CorrectCoordianteExtent(extent);
            }
            tileProjection.CoordExtent = extent;
            if (minZoomLevel == null || !projection.CheckZoomLevel(minZoomLevel.Value))
            {
                tileProjection.MinZoomLevel = projection.MIN_ZOOM_LEVEL;
            }
            else
            {
                tileProjection.MinZoomLevel = minZoomLevel.Value;
            }
            if (maxZoomLevel == null || !projection.CheckZoomLevel(maxZoomLevel.Value))
            {
                tileProjection.MaxZoomLevel = projection.MAX_ZOOM_LEVEL;
            }
            else
            {
                tileProjection.MaxZoomLevel = maxZoomLevel.Value;
            }
            // TileExtent: key,level;value,TileExtent
            tileProjection.TileExtentCollection = new Dictionary <int, TileExtent>();
            // 遍历所有Level
            for (int i = tileProjection.MinZoomLevel; i <= tileProjection.MaxZoomLevel; i++)
            {
                TileExtent tileExtent = new TileExtent();
                tileExtent.ProjType  = projType;
                tileExtent.ZoomLevel = i;
                // 计算当前范围
                double originX = projection.MIN_X;
                double originY = projection.MAX_Y;

                tileExtent.MinRowIndex = Convert.ToInt32(
                    Math.Floor(
                        (originY - extent.MaxY) / (projection.TILE_SIZE * projection.GetZoomResolution(i))
                        ));
                tileExtent.MinColumnIndex = Convert.ToInt32(
                    Math.Floor(
                        (originX - extent.MinX) / (projection.TILE_SIZE * projection.GetZoomResolution(i))
                        ));
                tileExtent.MaxRowIndex = Convert.ToInt32(
                    Math.Ceiling(
                        (originY - extent.MinY) / (projection.TILE_SIZE * projection.GetZoomResolution(i))
                        ));
                tileExtent.MaxColumnIndex = Convert.ToInt32(
                    Math.Ceiling(
                        (originX - extent.MaxX) / (projection.TILE_SIZE * projection.GetZoomResolution(i))
                        ));

                tileExtent.RowNumber    = tileExtent.MaxRowIndex - tileExtent.MinRowIndex + 1;
                tileExtent.ColumnNumber = tileExtent.MaxColumnIndex - tileExtent.MinColumnIndex + 1;

                // 添加到集合
                tileProjection.TileExtentCollection.Add(i, tileExtent);
            }

            return(tileProjection);
        }