通过segue进行数据传输

在viewControl中，加入-（void）prepareForSegue:(UIStoryBoardSegue *)segue sender: (id)sender方法，会在通过segue跳转之前执行。

-（void）prepareForSegue:(UIStoryBoardSegue *)segue sender: (id)sender{
 id destController=segue.destinationViewController;//获取segue将要跳转到的目标视图控制器
 destController setValue:self.label.text forKey:@"XXX"];//通过KVC方式将label内的文本设为destController的XXX的属性值
}

For example, if the segue originated from a table view, the sender parameter would identify the table view cell that the user tapped. You could use that information to set the data on the destination view controller.

当你点击一个表格单元格进行segue跳转，调用prepareForSegue方法时，sender参数就是你点击的那个表格单元格，你可以用这个信息来设置目标VC的数据。

UIStoryBoardSegue有三个property，destinationViewController,sourceViewController,identifier.当一个viewController有多个segue并且要调用prepareForSegue时，通过identifier进行区分segue。

if you have a source view controller that can segue to two or more different destination view controllers, you would assign different identifiers to each segue so that the source view controller’s prepareForSegue:sender: method could tell them apart and prepare each segue appropriately.