如何获取selectionChanged信号

Question

嗨，我正在用python开发一个Qgis插件，我需要连接选择图层要素时发出的sselectionChanged信号，我在互联网上找不到任何示例，这是我到目前为止所做的工作

QObject.connect(self.iface.mapCanvas(),SIGNAL("selectionChanged(QgsMapLayer)"), self.test)

在qgis的日志中，我收到以下警告

Warning: Object::connect:  (receiver name: 'MainWindow')

Answer 1

您需要做的是在每次选择一个层时创建一个信号：

def initGui(self):
    # ... your other code here
    self.handler = None
    self.selected_layer = None
    QObject.connect(self.iface,SIGNAL("currentLayerChanged(QgsMapLayer *)") ,self.layerChanged)

def layerChanged(self, layer):
    if self.handler:
        QObject.disconnect(self.selected_layer, SIGNAL("selectionChanged()"),self.select_changed)
        self.handler = False
        self.selected_layer = None
    if layer is not None:
        if layer.isValid():
            QObject.connect(layer,SIGNAL("selectionChanged()"),self.select_changed)
            self.selected_layer = layer

def select_changed(self):
   # whatever
   pass

编辑:断开连接(错误图层)已修复