[GIS] Does mapCanvas().refresh() not work in QGIS 2.6

pyqgispythonqgisqgis-2.6

Before I used the function

qgis.utils.iface.mapCanvas().refresh()

to reload the map canvas after for example a layer color was changed from a plugin.
But this is not working with QGIS 2.6 for me.
Do I have to use another function to refresh the map canvas or is this a bug?

Best Answer

It may very well be a bug as I also cannot get the canvas to refresh. You can try the following as a workaround:

myLayer.triggerRepaint()

To refresh all layers following function can be used:

def refresh_layers(self):
    for layer in qgis.utils.iface.mapCanvas().layers():
        layer.triggerRepaint()

Related Solutions

[GIS] Send signal when attributes modified – QGIS 2.6

I've tested the attributeValueChanged SIGNAL in a created-from-scratch test plugin using QGIS v.2.6.1

You can connect the SIGNAL to your slot this way (I did it in my run() method):

def run(self):
    self.lyr = self.iface.mapCanvas().layers()[0]
    self.lyr.attributeValueChanged.connect(self.mySlot)

And then, you have two options to write your slot (see mySlot and mySlot2):

def mySlot(self):
    QMessageBox.information( self.iface.mainWindow(), "Test", 
        "Attributes were changed!!!", QMessageBox.Ok )

def mySlot2(self, fid, idx, v):
    QMessageBox.information( self.iface.mainWindow(), "Test", 
        "Attributes changed for feature " + str(fid), QMessageBox.Ok )

Both slots work, just replace self.mySlot by self.mySlot2 in the connect method above if you want to switch between them.

If you want to get the test plugin, run it on your QGIS, and have a look at the code, you can access to it here. You find installation and usage instructions in the README file.

Best Answer

Related Solutions

[GIS] Send signal when attributes modified – QGIS 2.6

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