Using QGIS 2.18.1, I started to create a shapefile layer with a line feature, but then decided not to proceed. I first tried to select and delete the lines but couldn't seem to select them with the select tool. So I then deleted the shapefiles using File Explorer which seemed to go as expected. However, the lines are still on the canvas, and appear to be impossible to delete, and of course are no longer associated with a layer . How can I clear the canvas of these lines?
[GIS] How to delete lines from the QGIS canvas which no longer are attached to a shapefile
linestringqgisshapefile
Related Solutions
Both your layers are not alligned correctly. Instead of manipulating the vertices of both layers to match up, I would suggest starting afresh and download the shapefile for Ireland from ArcGIS which contains two polygons for both Ireland and Northern Ireland:
You could then split this layer into two using the Split vector layer tool:
Processing Toolbox > QGIS geoalgorithms > Vector general tools > Split vector layer
Note that Northern Ireland is not broken up into counties as shown in your image, so we could use the Intersect tool:
Processing Toolbox > QGIS geoalgorithms > Vector overlay tools > Intersection
Choose the Northern Ireland polygon you received from the Split vector layer tool as the Input layer and your Northern Ireland counties layer as Intersect layer. Your new layer should now have the same counties as your original layer but still alligned perfectly:
As @ndawson correctly commented:
They weren't memory layers, they were just shapefiles stored in a temporary location (and subject to all the limitations present in the shapefile format!)
The final note is that the name "memory layer" was improperly used.
Best Answer
That's all.