QGIS-2.8-PyQGISDeveloperCookbook-en(3)

为开发人员准备的文档,涵盖QGIS的多种功能实现和代码。

Contents

1Introduction

1.1RunPythoncodewhenQGISstarts

1.2PythonConsole...........

1.3PythonPlugins...........

1.4PythonApplications............................................................................................................................................11223

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362LoadingProjects3LoadingLayers3.1VectorLayers.............................................3.2RasterLayers.............................................3.3MapLayerRegistry.....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................4UsingRasterLayers4.1LayerDetails...4.2DrawingStyle..4.3RefreshingLayers4.4QueryValues...5UsingVectorLayers5.1Retrievinginformationsaboutattributes.....5.2Selectingfeatures.................5.3IteratingoverVectorLayer............5.4ModifyingVectorLayers.............5.5ModifyingVectorLayerswithanEditingBuffer5.6UsingSpatialIndex...............5.7WritingVectorLayers..............5.8MemoryProvider.................5.9Appearance(Symbology)ofVectorLayers...5.10FurtherTopics..................6GeometryHandling6.1GeometryConstruction.......................................6.2AccesstoGeometry.........................................6.3GeometryPredicatesandOperations................................7ProjectionsSupport7.1Coordinatereferencesystems....................................7.2Projections..............................................8UsingMapCanvas8.1EmbeddingMapCanvas.......................................8.2UsingMapToolswithCanvas....................................