C# TileSet.IsCached方法代码示例

        /// <summary>
        /// Create an image for this layer by stitching together tile images.
        /// </summary>
        /// <param name="oLayerBoundingBox">
        /// The bounding box for the layer. Tiles outside this bounding box will not be drawn.
        /// </param>
        /// <param name="oViewBoundingBox">
        /// The bounding box of the view. The resulting image will be scaled and
        /// cropped to fill this view.
        /// </param>
        /// <returns>The raw data of the composed image.</returns>
        public byte[] GetCompositeImage(BoundingBox oLayerBoundingBox, BoundingBox oViewBoundingBox)
        {
            if (!oLayerBoundingBox.Intersects(oViewBoundingBox))
                return BlankImageBytes();

            BoundingBox visibleDataBounds = oLayerBoundingBox.IntersectWith(oViewBoundingBox);

            //bool moreDataComing = false;
            TileSet oRequiredTiles = new TileSet(visibleDataBounds, TileSet.GetLevel(oViewBoundingBox));
            TileSet oServiceTiles = oRequiredTiles;

            // --- Keep going to lower-levelled tiles until we can service the request ---

            System.Diagnostics.Debug.WriteLine("Requesting composite image at level " + oServiceTiles.Level);
            while (oServiceTiles.Level > 0 && !oServiceTiles.IsCached(this, oLayerBoundingBox))
            {
                oRequiredTiles = oServiceTiles;
                oServiceTiles = new TileSet(visibleDataBounds, oServiceTiles.Level - 1);
                //moreDataComing = true;
                System.Diagnostics.Debug.WriteLine("Decrementing level to " + oServiceTiles.Level);
            }

            // --- Queue up the other images for the request ---

            if (!oRequiredTiles.IsCached(this, oLayerBoundingBox))
            {
                DownloadSet oRequiredDownloads = new DownloadSet(this, oRequiredTiles, oLayerBoundingBox);
                oRequiredDownloads.DownloadAsync(new EventHandler(oRequiredDownloads_DownloadComplete));
            }

            // --- Compose image tiles to master tile ---

            Bitmap composite = ComposeImageFromTileCache(oServiceTiles);
            BoundingBox compositeBounds = oServiceTiles.Bounds;
            double degreesPerPixel = TileInfo.GetTileSize(oServiceTiles.Level) / TileInfo.TileSizePixels;

            // --- Render the image for the tile level requested ---

            Bitmap result = new Bitmap((int)((oViewBoundingBox.MaxX - oViewBoundingBox.MinX) / degreesPerPixel), (int)((oViewBoundingBox.MaxY - oViewBoundingBox.MinY) / degreesPerPixel));
            BoundingBox resultBounds = new BoundingBox(oViewBoundingBox);

            using (Graphics g = Graphics.FromImage(result))
            {
                g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;

                g.DrawImage(composite, new PointF((float)((compositeBounds.MinX - resultBounds.MinX) / degreesPerPixel), (float)((resultBounds.MaxY - compositeBounds.MaxY) / degreesPerPixel)));

                //if (moreDataComing)
                //   g.FillRectangle(new System.Drawing.Drawing2D.HatchBrush(System.Drawing.Drawing2D.HatchStyle.Percent05, Color.Green, Color.Transparent), 0, 0, result.Width, result.Height);
            }

            result.Save("C:/documents and settings/chrismac/desktop/sent.png", System.Drawing.Imaging.ImageFormat.Png);

            MemoryStream buffer = new MemoryStream();
            result.Save(buffer, System.Drawing.Imaging.ImageFormat.Png);
            return buffer.ToArray();
        }