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【QGIS_Python】在QGIS的Python控制台生成SHP格式点数据并显示标注

news 来源：原创 2025/5/15 9:44:05

参考文章：「GIS教程」使用DeepSeek辅助QGIS快速制图 | 麻辣GIS

示例代码说明：使用参考文章中的省会城市坐标点，左侧增加一列城市序号code, 图层标注显示 code + 城市名称，同时在指定路径下生成对应SHP格式点数据。

import os
from qgis.core import QgsVectorLayer, QgsField, QgsFeature, QgsGeometry, QgsPointXY, QgsProject, QgsMarkerSymbol, QgsPalLayerSettings, QgsVectorLayerSimpleLabeling
from qgis.PyQt.QtCore import QVariant

# 创建省会城市坐标字典（名称, 经度, 纬度）
capital_cities = {"北京": (116.4074, 39.9042), "天津": (117.1994, 39.0851), "石家庄": (114.4995, 38.0409),
                  "太原": (112.5489, 37.8706), "呼和浩特": (111.7510, 40.8415), "沈阳": (123.4315, 41.8057),
                  "长春": (125.3236, 43.8160), "哈尔滨": (126.5350, 45.8022), "上海": (121.4737, 31.2304),
                  "南京": (118.7969, 32.0603), "杭州": (120.1551, 30.2741), "合肥": (117.2272, 31.8206),
                  "福州": (119.2965, 26.0745), "南昌": (115.8581, 28.6829), "济南": (117.1205, 36.6510),
                  "郑州": (113.6253, 34.7466), "武汉": (114.3054, 30.5928), "长沙": (112.9388, 28.2278),
                  "广州": (113.2644, 23.1291), "南宁": (108.3663, 22.8176), "海口": (110.1999, 20.0440),
                  "重庆": (106.5516, 29.5630), "成都": (104.0665, 30.5728), "贵阳": (106.6302, 26.6477),
                  "昆明": (102.8329, 24.8801), "拉萨": (91.1406, 29.6455), "西安": (108.9398, 34.3416),
                  "兰州": (103.8342, 36.0611), "西宁": (101.7778, 36.6173), "银川": (106.2309, 38.4872),
                  "乌鲁木齐": (87.6168, 43.8256), "香港": (114.1694, 22.3193), "澳门": (113.5439, 22.1987),
                  "台北": (121.5645, 25.0330)
                  }

# 定义输出 Shapefile 路径
output_dir = "C:/Users/QGIS/data/output"  # 修改为你的输出目录
output_shp = os.path.join(output_dir, "provincial_capitals.shp")

# 创建点图层
layer = QgsVectorLayer("Point?crs=EPSG:4326", "Provincial Capitals", "memory")
provider = layer.dataProvider()

# 添加字段
provider.addAttributes(
    [QgsField("code", QVariant.Int),
     QgsField("city", QVariant.String),
     QgsField("longitude", QVariant.Double),
     QgsField("latitude", QVariant.Double)])
layer.updateFields()

# 添加要素
code = 1  # 从1开始编号
for city, (lon, lat) in capital_cities.items():
    feat = QgsFeature()
    feat.setGeometry(QgsGeometry.fromPointXY(QgsPointXY(lon, lat)))
    feat.setAttributes([code, city, lon, lat])
    provider.addFeature(feat)
    code += 1  # 编号递增

# 设置符号样式
symbol = QgsMarkerSymbol.createSimple({'name': 'circle', 'color': 'red', 'size': '5.0'})
layer.renderer().setSymbol(symbol)

# 添加标注设置
label_settings = QgsPalLayerSettings()
label_settings.isExpression = True  # 启用表达式
label_settings.fieldName = "concat(code, ', ', city)"  # 使用表达式拼接 code 和 city
label_settings.placement = QgsPalLayerSettings.AroundPoint
label_settings.enabled = True
# 设置字体样式
text_format = QgsTextFormat()
text_format.setFont(QFont("Arial", 20))  # 设置字体为 Arial，大小为 20
text_format.setColor(QColor("black"))  # 设置字体颜色为黑色
label_settings.setFormat(text_format)

labeler = QgsVectorLayerSimpleLabeling(label_settings)
layer.setLabeling(labeler)
layer.setLabelsEnabled(True)

# 保存为 Shapefile
error = QgsVectorFileWriter.writeAsVectorFormat(layer, output_shp, "UTF-8", driverName="ESRI Shapefile")
if error[0] == QgsVectorFileWriter.NoError:
    print(f"Shapefile 已成功保存到: {output_shp}")
else:
    print(f"保存 Shapefile 时出错: {error[1]}")

# 添加到地图（可选）
QgsProject.instance().addMapLayer(layer)
print(f"已成功加载 {len(capital_cities)} 个省会城市坐标点")

结果示例：