我试图循环获得两层之间的重叠特征。在大多数情况下，这可以正常工作，但在某些情况下，会引发例外情况。异常回溯甚至都没有提供任何有关异常的提示。
代码：
feature1_layers_list = []
feature2_layers_list = []
layer1 = QgsVectorLayer('Polygon?crs=epsg:4326', 'Layer1', 'memory')
prov = layer1.dataProvider()
prov.addAttributes([QgsField("flash_feat_id", QVariant.Int)])
prov.addAttributes([QgsField("lane_type", QVariant.String)])
prov.addAttributes([QgsField("center_line_Id", QVariant.String)])
layer1.updateFields()
for feature1_centerline in feature1_all_center_lines:
feature1_Lane_Polygon, lanetype1, center_line_id1 = self.get_lane_border(feature1_centerline,
self.laneCenterline_layer,
centerlineFeatures,
laneBorder_layer,
laneBorderFeatures)
if feature1_Lane_Polygon != 0 and lanetype1 != 0:
fet = QgsFeature()
fields = layer1.fields()
fet.setFields(fields, True)
fet.setGeometry(QgsGeometry.fromWkt(feature1_Lane_Polygon.wkt))
fet['flash_feat_id'] = int(center_line_id1)
fet['lane_type'] = str(lanetype1)
fet['center_line_Id'] = str(feature1_centerline)
feature1_layers_list.append(fet)
prov.addFeatures(feature1_layers_list)
layer1.updateExtents()
layer2 = QgsVectorLayer('Polygon?crs=epsg:4326', 'Layer2', 'memory')
prov2 = layer2.dataProvider()
prov2.addAttributes([QgsField("flash_feat_id", QVariant.Int)])
prov2.addAttributes([QgsField("lane_type", QVariant.String)])
prov2.addAttributes([QgsField("center_line_Id", QVariant.String)])
layer2.updateFields()
# _writer1 = QgsVectorFileWriter.writeAsVectorFormat(layer1,
# r"C:/QGIS_ShapeFile/output/layer1.shp",
# "utf-8", driverName="ESRI Shapefile")
# _writer2 = QgsVectorFileWriter.writeAsVectorFormat(layer2,
# r"C:/QGIS_ShapeFile/output/layer2.shp",
# "utf-8", driverName="ESRI Shapefile")
for feature2_centerline in feature2_all_center_lines:
feature2_Lane_Polygon, lanetype2, center_line_id2 = self.get_lane_border(feature2_centerline,
self.laneCenterline_layer,
centerlineFeatures,
laneBorder_layer,
laneBorderFeatures)
if feature2_Lane_Polygon != 0 and lanetype2 != 0:
feat = QgsFeature()
fields2 = layer2.fields()
feat.setFields(fields2, True)
feat.setGeometry(QgsGeometry.fromWkt(feature2_Lane_Polygon.wkt))
feat['flash_feat_id'] = int(center_line_id2)
feat['lane_type'] = str(lanetype2)
feat['center_line_Id'] = str(feature2_centerline)
feature2_layers_list.append(feat)
prov2.addFeatures(feature2_layers_list)
layer2.updateExtents()
uuid1 = uuid.uuid4()
uuid2 = uuid.uuid4()
layer3_path = 'C:/QGIS_ShapeFile/output/layers/layer_' + str(uuid1) + '.shp'
layer4_path = 'C:/QGIS_ShapeFile/output/layers/layer_' + str(uuid2) + '.shp'
try:
algorithmOutput1 = processing.run(
"qgis:extractbylocation",
{
'INPUT': layer1,
'INTERSECT': layer2,
'OUTPUT': layer3_path,
'PREDICATE': [5]
}
)
algorithmOutput2 = processing.run(
"qgis:extractbylocation",
{
'INPUT': layer2,
'INTERSECT': layer1,
'OUTPUT': layer4_path,
'PREDICATE': [5]
}
)
layer3 = QgsVectorLayer(layer3_path, "layer3", "ogr")
layer4 = QgsVectorLayer(layer4_path, "layer4", "ogr")
self.get_overlap_pair(layer3, layer4)
except Exception as e:
traceback.print_exc()
下面是堆栈跟踪：
回溯（最近通话最近）：文件 “ C：/ Users / sn43673 / AppData / Roaming / QGIS / QGIS3 \ profiles \ default / python / plugins \ ad_qgis \ shapefile_validator.py”， 440行，在errorInShapeFile中 'PREDICATE'：[5]文件“ C：/PROGRA~1/QGIS3~1.6/apps/qgis /./ python / plugins \ processing \ tools \ general.py”， 105行，运行中 返回Processing.runAlgorithm（algOrName，参数，onFinish，反馈，上下文）文件 “ C：/PROGRA~1/QGIS3~1.6/apps/qgis /./ python / plugins \ processing \ core \ Processing.py”， 第183行，在runAlgorithm中 引发QgsProcessingException（msg） _core.QgsProcessingException：执行算法时出错。
答案 0 :(得分：2)
此错误是由于图层layer1和layer2中的要素几何无效所致。我验证了特征的所有几何形状，并知道了这一点。该算法现在可以正常工作。