ios 导航栏back按钮title更改

首先，要更改navigationController的back btn的title是要在当前视图的父视图进行更改的。

UIBarButtonItem *backButton = [[UIBarButtonItem alloc] initWithTitle:@”Back” style:UIBarButtonItemStyleBordered target:nil action:nil];
[[self navigationItem] setBackBarButtonItem:backButton];