使用标签栏控制器离开时如何关闭视图

I use a tab bar controller to go from VC1 to VC2. Doing so, VC1 stays in memory. I manage data with VC2 and when I go back to VC1 (with tab bar controller), I reload VC1 with a function in I use a tab bar controller to go from VC1 to VC