require(['dojo/when']);
var json = new JsonRest({target: url});

    store = new ObjectStore({objectStore: json});
    
    store.onFetch = function(results){
        // 方法一：
    	results.then(function(rs){
    		console.log('rs len->',rs.length);
    	});
        // 方法二：
    	when(results,function(results){
    		console.log('when->',results.length);
    		console.dir(results);
    	});
    };