Sanya-ips/ipslib/Ips.Library.DxpLib.Map/SqliteTileGenerator.cs

using DevExpress.XtraMap;
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Imaging;
using System.Linq;
using System.Text;
using System.IO;
using System.Threading.Tasks;
using System.Data.SQLite;
using System.Data.Common;
using System.Runtime.InteropServices;
using System.Windows.Forms;
using Ips.Library.Basic;

namespace Ips.Library.DxpLib
{
    public class SqliteTileGenerator : IImageTileSource
    {
        public SqliteTileGenerator(string filename = null)
        {
            FileName = filename.IfNullOrWhitespace(DefaultDBTileFile);
            ConnectionString = string.Format("Data Source=\"{0}\";Page Size=32768;Pooling=True", FileName);
        }

        public static string DefaultDBTileFile = Path.Combine(IpsPath.RootDir,"AppData","map","map.dat");

        public string Name => nameof(SqliteTileGenerator);

        public bool CanDisposeSourceImage => true;

        public string FileName { get; set; }

        public string ConnectionString { get; private set; }

        public int MapType { get; set; } = 1082287436;//MapConsts.NormalMapNum;

        public const string querySql = "SELECT Tile FROM TilesData WHERE id = (SELECT id FROM Tiles WHERE X={0} AND Y={1} AND Zoom={2} AND Type={3})";

        public Image GetImage(int x, int y, int level, Size size)
        {
            Image ret = null;
            using (var con = new SQLiteConnection())
            {
                con.ConnectionString = ConnectionString;
                con.Open();
                using (var cmd = con.CreateCommand())
                {
                    cmd.CommandText = string.Format(querySql, x, y, level, MapType);
                    using (DbDataReader rd = cmd.ExecuteReader(System.Data.CommandBehavior.SequentialAccess))
                    {
                        if (rd.Read())
                        {
                            long length = rd.GetBytes(0, 0, null, 0, 0);
                            byte[] tile = new byte[length];
                            rd.GetBytes(0, 0, tile, 0, tile.Length);
                            using (MemoryStream ms = new MemoryStream(tile, 0, tile.Length, false, true))
                            {
                                ret = Image.FromStream(ms);
                            }
                            tile = null;
                        }
                        rd.Close();
                    }
                }
            }
            return ret;
        }
    }
}