sharpmap

name	sharpmap
description	Use when rendering 2D maps in legacy .NET WinForms or ASP.NET WebForms applications. SharpMap: an older .NET 2D mapping library. For new projects, prefer Mapsui.
tags	["dotnet","csharp","2d","map","rendering","wms","shapefile","postgis","winforms"]

项目地址： https://github.com/SharpMap/SharpMap

官方文档： https://github.com/SharpMap/SharpMap/wiki

NuGet： SharpMap、SharpMap.UI.WinForms

许可证： LGPL-2.1

概述

SharpMap 提供：

• 数据源：Shapefile、PostGIS、SQL Server Spatial、Oracle Spatial、SQLite/SpatiaLite、WMS、WFS、TileSource（OSM/Bing）
• 图层模型：VectorLayer、LabelLayer、TileLayer、WmsLayer
• 样式：VectorStyle、LabelStyle、按属性主题样式
• 坐标变换：通过 ProjNet
• 几何：基于 NetTopologySuite
• 渲染：System.Drawing 位图 / WMS 服务输出
• UI 控件：WinForms MapBox

注意：SharpMap 主要面向 .NET Framework / 较旧 .NET，新项目建议改用 Mapsui。

---

安装

dotnet add package SharpMap
dotnet add package SharpMap.UI.WinForms
dotnet add package SharpMap.Extensions
dotnet add package ProjNet

---

核心对象

类型	说明
Map	地图
ILayer / VectorLayer / LabelLayer / TileLayer	图层
IProvider	数据提供者
VectorStyle / LabelStyle	样式

---

WinForms 入门

using SharpMap;
using SharpMap.Layers;
using SharpMap.Data.Providers;
using SharpMap.Styles;
using System.Drawing;

var map = new Map(new Size(800, 600));

var prov = new ShapeFile("countries.shp", true);
var layer = new VectorLayer("countries", prov)
{
    Style = new VectorStyle {
        Fill = new SolidBrush(Color.LightGreen),
        Outline = Pens.Black,
        EnableOutline = true
    }
};
map.Layers.Add(layer);

var labels = new LabelLayer("labels") {
    DataSource = prov,
    LabelColumn = "NAME",
    Style = new LabelStyle { Font = new Font("Arial", 10) }
};
map.Layers.Add(labels);

map.ZoomToExtents();
mapBox1.Map = map;
mapBox1.Refresh();

---

PostGIS 数据源

var conn = "Host=localhost;Database=gisdb;User Id=postgres;Password=pg";
var prov = new PostGIS(conn, "poi", "geom", "id");
map.Layers.Add(new VectorLayer("poi", prov));

---

OSM 瓦片底图

using BruTile.Predefined;
var src = KnownTileSources.Create(KnownTileSource.OpenStreetMap);
map.Layers.Add(new TileAsyncLayer(src, "OSM"));
map.SRID = 3857;

---

主题样式

using SharpMap.Rendering.Thematics;

var theme = new CustomTheme(row => {
    var pop = (int)row["POP"];
    return new VectorStyle {
        Fill = new SolidBrush(pop > 1_000_000 ? Color.Red : Color.Blue)
    };
});
layer.Theme = theme;

---

坐标变换

using ProjNet.CoordinateSystems;
using ProjNet.CoordinateSystems.Transformations;

var ctf = new CoordinateTransformationFactory();
layer.CoordinateTransformation = ctf.CreateFromCoordinateSystems(
    GeographicCoordinateSystem.WGS84,
    ProjectedCoordinateSystem.WebMercator);
map.SRID = 3857;

---

输出图像与 WMS

using var img = map.GetMap();
img.Save("map.png");

// ASP.NET WMS
public void ProcessRequest(HttpContext ctx)
{
    var map = MapHelper.InitializeMap();
    SharpMap.Web.Wms.WmsServer.ProcessRequest(ctx, map);
}

---

拾取与查询

mapBox1.MouseDown += (s, e) => {
    var pt = mapBox1.Map.ImageToWorld(new PointF(e.X, e.Y));
    var ds = new SharpMap.Data.FeatureDataSet();
    layer.DataSource.ExecuteIntersectionQuery(
        new NetTopologySuite.Geometries.Envelope(pt.X-1e-3, pt.X+1e-3,
                                                 pt.Y-1e-3, pt.Y+1e-3), ds);
    foreach (FeatureDataRow row in ds.Tables[0].Rows)
        Console.WriteLine(row["NAME"]);
};

---

性能建议

1. 预建空间索引（Shapefile .qix、PostGIS GiST）
2. TileAsyncLayer 用于在线底图
3. 避免主线程加载大数据
4. LabelLayer 启用优先级与碰撞检测
5. 复用 Brush/Pen/VectorStyle

---

常见问题

问题	解决
无图	检查 SRID、ZoomToExtents
文字模糊	设置高 DPI Aware、MapBox.MapTransform
GDI+ 内存泄漏	释放 Brush/Pen/Bitmap
Shapefile 中文乱码	new ShapeFile(path, true, false, Encoding.UTF8)

---

典型工作流

工作流 1：Shapefile 渲染 + 主题样式 + 输出图片

using SharpMap;
using SharpMap.Layers;
using SharpMap.Data.Providers;
using SharpMap.Styles;
using SharpMap.Rendering.Thematics;
using System.Drawing;

// 创建地图
var map = new Map(new Size(1024, 768));
map.SRID = 4326;

// 添加 Shapefile 图层
var prov = new ShapeFile("countries.shp", true);
var layer = new VectorLayer("Countries", prov)
{
    Style = new VectorStyle
    {
        Fill = Brushes.LightGreen,
        Outline = Pens.Black,
        EnableOutline = true
    }
};

// 按人口设置主题样式
layer.Theme = new CustomTheme(row =>
{
    var pop = (int)row["POP_EST"];
    return new VectorStyle
    {
        Fill = new SolidBrush(pop > 100_000_000 ? Color.Red : Color.LightBlue)
    };
});
map.Layers.Add(layer);

// 添加行政标注
var labels = new LabelLayer("Labels")
{
    DataSource = prov, LabelColumn = "NAME",
    Style = new LabelStyle { Font = new Font("Arial", 10) }
};
map.Layers.Add(labels);

// 渲染
map.ZoomToExtents();
using var img = map.GetMap();
img.Save("output.png");

工作流 2：PostGIS 数据 + OSM 底图 + WMS 发布

// PostGIS 数据
var pgConn = "Host=localhost;Database=gisdb;User Id=postgres;Password=pg";
var poiProvider = new PostGIS(pgConn, "poi", "geom", "id");
map.Layers.Add(new VectorLayer("POI", poiProvider)
{
    Style = new VectorStyle { Fill = Brushes.OrangeRed }
});

// OSM 底图
using BruTile.Predefined;
var tileSrc = KnownTileSources.Create(KnownTileSource.OpenStreetMap);
map.Layers.Add(new TileAsyncLayer(tileSrc, "OSM"));
map.SRID = 3857;

AI 使用建议

推荐工作流

1. 创建 Map：new Map(new Size(width, height)) → 设置 SRID
2. 添加数据源：ShapeFile(path) / PostGIS(conn, table, geomCol, idCol) 等方式连接数据
3. 创建图层：VectorLayer(name, provider) 并设置 Style；按需添加 LabelLayer
4. 添加底图：TileAsyncLayer + BruTile 加载 OSM 在线底图
5. 渲染输出：map.GetMap() 获取 Image 对象 → 保存为 PNG 或通过 ASP.NET WMS 发布

关键注意事项

• 新项目建议 Mapsui：SharpMap 主要面向 .NET Framework，新项目推荐使用 Mapsui（更活跃、跨平台更好）
• SRID 一致性：图层与地图 SRID 必须一致，必要时通过 CoordinateTransformation 转换
• 空间索引：Shapefile 需预建 .qix 索引，PostGIS 用 GiST 索引加速查询
• 资源释放：GDI+ Brush/Pen/Bitmap 需及时释放避免内存泄漏
• Shapefile 编码：中文数据需指定 Encoding.UTF8 或 Encoding.GetEncoding("GBK")

相关技能

• mapsui — .NET 现代跨平台地图组件（推荐替代）：../mapsui/SKILL.md
• nettopologysuite — .NET 几何计算核心：../nettopologysuite/SKILL.md
• openlayers — Web 二维地图库：../openlayers/SKILL.md
• postgis — 空间数据库：../postgis/SKILL.md

参考资源

• Wiki：https://github.com/SharpMap/SharpMap/wiki
• 中文教程（znlgis）：https://znlgis.github.io/gis/tutorial/sharpmap/