How to save tmx file with CCTMXTiledMap

CCTMXTiledMap *map = [CCTMXTiledMap tiledMapWithTMXFile:@"mapTmx.tmx"];
CCTMXLayer *l开发者_如何学Cayer = [map layerNamed:@"Layer 0"];
[layer setTileGID:10  at:ccp( 0, 0 )];

How can I save "CCTMXTiledMap *map" to "mapTmx.tmx" file?

This default functionality doesn't exist. You could export a tmx through Tiled to one of the text formats and cobble together your own exporter. Not the answer you wanted, but it's a start.