+ table.frame = CGRectMake(0.0, 0.0, 300.0, 45.0);
+ [table layoutIfNeeded]; // so autolayout can do its thing and then we can measure a cell
+ UITableViewCell* cell = table.visibleCells.firstObject;
+ CGFloat heightForOneRow = cell ? CGRectGetHeight(cell.frame) : 45.0;