1.A视图控制器:
BViewController *BVC = [[BViewController alloc]init];
[self presentViewController:BVC animated:YES completion:nil];
2.B视图控制器:
运行APP,点击左上角的返回按钮时,调用
[self dismissViewControllerAnimated:YES completion:nil];
控制台提示警告:
Warning: Attempt to present <ModalViewController> on <ViewController>while a presentation is in progress
3.我修改了A视图控制器:
if(_BVC == nil){ _BVC = [[BViewController alloc]init]; } [self presentViewController:BVC animated:YES completion:nil];
运行APP,点击B视图控制器左上角的返回按钮,程序报错:
exception.reason: Application tried to present modally an active controller
4.在百度找到一贴,修改A视图控制器:
if(_BVC == nil){ _BVC = [[BViewController alloc]init]; } if (self.presentedViewController == nil) { [self presentViewController:BVC animated:YES completion:nil]; }