var data:Array = getDataFromSomewher();

// dgAC – ArrayCollection bound to a DataGrid

for each ( var tmp:MyDomainObject in data ) {
dgAC.source.push( tmp );
}
dgAC.refresh();

This will add the stuff from ‘data’ into the Array that the ‘dgAC’ ArrayCollection wraps without firing events. Then the call to ‘refresh’ fires off an event telling whoever is listening that the contents changed!

Ever try that??