R: Re: R: Re: [Qgis-developer] Trasform QgsVectorLayer proj4 to another

[francescoboccacci at libero.it]

Solved..thank to:

  feature.geom.transform(srsTransform)

Thanks

Francesco

>----Messaggio originale----
>Da: rdmailings at duif.net
>Data: 14/12/2011 14.28
>A: "francescoboccacci at libero.it"<francescoboccacci at libero.it>
>Cc: <qgis-developer at lists.osgeo.org>
>Ogg: Re: R: Re: [Qgis-developer] Trasform QgsVectorLayer proj4 to another
>
>On 2011-12-14 13:55, francescoboccacci at libero.it wrote:
>> Hi,
>> i tried it but it works only with point tranformation. I would llike to 
>> tranform the entire vector layer.
>> Do you have any suggestions?
>
>Mmm, you are right, I only used it for one feature at the time.
>
>Then I think you just have to loop over every feature in the layer that
>you want to transform, and transform the geometry of each feature one by
>one?
>
>Given the QgsCoordinateTransform-object, you can transform one geometry
>by using it's 'transform' method:
>http://qgis.org/api/classQgsGeometry.html#46fd84e518cae4368aadeeac89574dfa
>
>Some copy and paste from imagemapplugin.py:
>
>destinationSrs = self.iface.mapCanvas().mapRenderer().destinationSrs()
>layerSrs = self.iface.activeLayer().srs()
>srsTransform = QgsCoordinateTransform(layerSrs, destinationSrs)
>...
>self.provider.select(self.provider.attributeIndexes(), mapCanvasExtent,
>True, True)
>...
>feature = QgsFeature();
>while self.rovider.nextFeature(feature):
>  feature.geom.transform(srsTransform)
>...
>
>See here:
>http://www.qgis.org/pyqgis-cookbook/vector.html#writing-vector-layers
>how to write a new file.
>
>Devs, please let know if this is not ok....
>
>By the way, I assume you are doing this from within a plugin or some
>python code? Because qgis itself can do coordinatetransformations for
>you when you use 'save layer as' .... in the gui.
>
>HTH,
>
>Richard Duivenvoorde
>
>