HelloWorld.JsonDataService.GetUnits C# (CSharp) Method

        public Unit[] GetUnits( Coordinate coordinate )
        {
            lock ( _unitSync )
              {

            HashSet<Unit> units;

            if ( _placeUnits.TryGetValue( coordinate, out units ) )
            {
              var invalids = units.Where( item => item.Coordinate != coordinate ).ToArray();//检查单位是否还在这个坐标。
              foreach ( var item in invalids )
            units.Remove( item );

              return units.ToArray();
            }
            else
              return new Unit[0];

              }
        }