How to deal Leaflet map control checkboxes?

Question

I add some geojson layers to the map control once a layer is loaded and the control can show all the layer names. But I notice that all the checkboxes are unchecked by default. So that once I click the control to uncollapse it, all the layers disappear. And I have to check them one by one to display them again.

The code is like:

ctrl = L.control.layers([aBaseLayer]); ctrl.addOverlay(aGeoJsonLayer, 'ageojsonlayer'); 

Then I can control the aGeoJsonLayer, but unlike the aBaseLayer, the aGeoJsonLayer is not checked by default in the control panel. So every time after the layer is loaded, when I click the control, the layer will be gone until I check it in the control panel. Any way to fix this?

Answer 1

Have you tried something like

L.control.layers([aBaseLayer], [aGeoJsonLayer]).addTo(map);

Although you may want to add your layer as a geojson layer: http://leafletjs.com/reference.html#geojson

Answer 2

Your code only creates a control layer and does not add your base layer or overlay to the map. So if your aBaseLayer and aGeoJsonLayer are not on the map when you create the control layer, the checkboxes will not be selected.