change the crs property of map dynamically

Recently one of our project need to change the crs at run-time(during we change the base layer of the map), and I found someone have meet the same requirement through #1818 , I have tried the manner it mentioned(by using the baselayerchange event, however the author use leaflet 0.5 while I am using 0.7.2 . Which means that it does not work.

So I tried to make it myself, this is what I tried:

layer.on('add',function(){
    var crs=getCrsByLayer(this);
    map.options.crs=crs; //reset the crs of the map

    //we have to clear this two properties, or the coord of the tile would be re-wrapped wrongly by the former crs of the map
    layer._wrapLng=null;
    layer._wrapLat=null;

       //it seems that the tiles calculation procedure have been done before the add event fired, so hack it to redraw the layer.
    layer.redraw();
});

However it does not work, so I tried to dig into the codes, and finally I found that the _initialTopLeftPoint property of the map does not changed when I reset the crs through map.options.crs, which means the tiles bounds will not calculated correctly. Since this is a private property, I do not think set it outside is a good idea.

So I think if you can re-consider this feature? It does not cause more codes, you just make the crs related property can be re-initialized.

Thank you.

[lhywell]

It’s the same problem at /issues/2553.And I use the baselayerchange Layer events to change multiple maps,Baidu use the CRS EPSG:900913,other map use EPSG3857.This is my demo:https://lhywell.github.io/map/example/example2/leaf2.html

map.on('baselayerchange', function(layer) {
        let center = map.getCenter();
        let zoom = map.getZoom();
        console.log(map.options.crs)
        if (layer.name.indexOf('百度') > -1) {
            map.options.crs = L.CRS.Baidu;
            map.options.tms = true;
            map._resetView(center, zoom, true);
        } else {
            map.options.crs = L.CRS.EPSG3857;
            map.options.tms = false;
            map._resetView(center, zoom, true);
        }
})

[guliash]

@Hashedhash, I have found a solution, it works but as not well as I’d like to. Something like this:

map.removeLayer(map.curLayer);
var center = map.getCenter();
map.options.crs = map.newLayer.crs;
map.setView(center); //we need this, because after changing crs the center is shifted (as mentioned above probably it's an issue to)
map._resetView(map.getCenter(), map.getZoom(), true); //we need this to redraw all layers (polygons, markers...) in the new projection.
map.addLayer(map.newLayer);