GeoJSON数据demo

以下是一个简单的GeoJSON数据示例：

{
    "type": "FeatureCollection",
    "features": [
        {
            "type": "Feature",
            "geometry": {
                "type": "Point",
                "coordinates": [102.0, 0.5]
            },
            "properties": {
                "name": "My Point"
            }
        },
        {
            "type": "Feature",
            "geometry": {
                "type": "LineString",
                "coordinates": [
                    [102.0, 0.0],
                    [103.0, 1.0],
                    [104.0, 0.0],
                    [105.0, 1.0]
                ]
            },
            "properties": {
                "name": "My Line"
            }
        },
        {
            "type": "Feature",
            "geometry": {
                "type": "Polygon",
                "coordinates": [
                    [
                        [100.0, 0.0],
                        [101.0, 0.0],
                        [101.0, 1.0],
                        [100.0, 1.0],
                        [100.0, 0.0]
                    ]
                ]
            },
            "properties": {
                "name": "My Polygon"
            }
        }
    ]
}

该示例包含一个FeatureCollection，其中包含三个要素：一个点、一条线和一个多边形。每个要素都有一个geometry属性和一个properties属性。geometry属性描述了要素的形状和位置，properties属性包含要素的其他相关信息，例如名称或ID。