ArcEngine 预览矢量图层渲染样式

   #region 预览
        /// <summary>
        /// 预览
        /// </summary>
        private void PreviewLineSymbol()
        {
            IStyleGalleryClass pStyleGalleryClass;//以下定义style类型
            pStyleGalleryClass = new LineSymbolStyleGalleryClassClass();
            this.previewBox.Image = Image.FromHbitmap(PreviewSymbol(pStyleGalleryClass, this.pStyleSymbol, this.previewBox.Width, this.previewBox.Height).GetHbitmap());
        }
        public Bitmap PreviewSymbol(IStyleGalleryClass pStyleGalleryClass, object symbolItem, int imgWidth, int imgHeight)
        {//获取图例Bitmap
            Bitmap bitmap = new Bitmap(imgWidth, imgHeight);            
            Graphics graphics = Graphics.FromImage(bitmap);
            tagRECT rect = new tagRECT();
            rect.right = bitmap.Width;
            rect.bottom = bitmap.Height;
            System.IntPtr hdc = graphics.GetHdc();
            pStyleGalleryClass.Preview(symbolItem, hdc.ToInt32(), ref rect);
            graphics.ReleaseHdc(hdc);
            graphics.Dispose();            
            return bitmap;
        }
        #endregion