GeoDjango 提供了一些专门的表单字段和小部件，以便在地图上可视化显示和编辑地理位置数据。默认情况下，它们使用由 NASA 提供的基本 WMS 图层，并由 OpenLayers 驱动的地图。
\n除了常规的 表单字段参数 之外，GeoDjango 表单字段还接受以下可选参数。
\nsridLink to this heading#这是字段值应该转换为的 SRID 代码。例如，如果地图小部件的 SRID 与您的应用程序或数据库通常使用的 SRID 不同，该字段将自动将输入值转换为该 SRID。
\ngeom_typeLink to this heading#通常情况下，您不应该设置或更改该属性，它应该根据字段类进行设置。它与 OpenGIS 标准的几何名称相匹配。
\nmax_geom_collectionsLink to this heading#The maximum number of geometry collections the field accepts before\nrefusing to parse the input and raising a\nValidationError. This guards against crashes\nin the underlying GEOS library when parsing deeply nested\nGEOMETRYCOLLECTION input. It defaults to 198.
The limit is applied differently depending on the input format: for\nwell-known text (WKT) it bounds the nesting depth, while for well-known\nbinary (WKB and hex-encoded WKB) it bounds the total number of geometry\ncollections (both breadth and depth). As a result, the same value may\naccept a wide, shallow collection as WKT but reject it as WKB. For GeoJSON,\nthe limit is not applied at all, since GDAL parses that input type instead.
\nIncrease this value (or set to None) only if you must accept\nlegitimately deep geometries, since doing so reduces protection against\nfatal errors.
GeometryFieldLink to this heading#PointFieldLink to this heading#LineStringFieldLink to this heading#PolygonFieldLink to this heading#MultiPointFieldLink to this heading#MultiLineStringFieldLink to this heading#MultiPolygonFieldLink to this heading#GeometryCollectionFieldLink to this heading#GeoDjango 表单小部件允许您在可视地图上显示和编辑地理数据。请注意，目前没有任何可用的小部件支持 3D 几何形状，因此对于这种类型的数据，几何字段将使用 Textarea 小部件作为回退。
GeoDjango 的小部件是基于模板的，因此它们的属性大部分与其他 Django 小部件的属性不同。
\nA string that specifies the identifier for the default base map layer to be\nused by the corresponding JavaScript map widget. It is passed as part of\nthe widget options when rendering, allowing the MapWidget to determine\nwhich map tile provider or base layer to initialize (default is None).
OpenGIS 几何类型，通常由表单字段设置。
\n地图使用的 SRID 代码（默认为 4326）。
\n布尔值，指定是否可见一个文本区域输入框，显示当前几何形状的序列化表示，主要用于调试目的（默认为 False）。
指示小部件是否支持编辑 3D 数据的属性（默认为 False）。
用于呈现地图小部件的模板。
\n您可以以与任何其他 Django 小部件相同的方式传递小部件属性。例如：
\nfrom django.contrib.gis import forms\n\n\nclass MyGeoForm(forms.Form):\n point = forms.PointField(widget=forms.OSMWidget(attrs={"display_raw": True}))\nBaseGeometryWidget
This is an abstract base widget containing the logic needed by subclasses.\nYou cannot directly use this widget for a geometry field.\nNote that the rendering of GeoDjango widgets is based on a base layer name,\nidentified by the base_layer class attribute.
OpenLayersWidget
This is the default widget used by all GeoDjango form fields. Attributes\nare:
\nnasaWorldview
gis/openlayers.html.
3857
OpenLayersWidget and OSMWidget include the ol.js and\nol.css files hosted on the cdn.jsdelivr.net content-delivery\nnetwork. These files can be overridden by subclassing the widget and\nsetting the js and css properties of the inner Media class (see\n资源作为静态定义).
OSMWidget
This widget specialized OpenLayersWidget and uses an OpenStreetMap\nbase layer to display geographic objects on. Attributes are:
osm
默认的中心纬度和经度分别是 47 和 5，这是法国东部的一个位置。
默认的地图缩放级别是 12。
The OpenLayersWidget note about using external assets also applies\nhere. See also this FAQ answer about https access to map tiles.
To customize the base layer displayed in OpenLayers-based geometry widgets,\ndefine a new layer builder in a custom JavaScript file. For example:
\npath-to-file.js MapWidget.layerBuilder.custom_layer_name = function () {\n // Return an OpenLayers layer instance.\n return new ol.layer.Tile({source: new ol.source.<ChosenSource>()});\n };\nThen, subclass a standard geometry widget and set the base_layer:
from django.contrib.gis.forms.widgets import OpenLayersWidget\n\n\nclass YourCustomWidget(OpenLayersWidget):\n base_layer = "custom_layer_name"\n\n class Media:\n js = ["path-to-file.js"]\n