【问题处理】Application tried to present modally an active controller

问题：

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Application tried to present modally an active controller <TabbarViewController: 0x1765dbe0>.'

解决方法：

判断controller是不是有presentedViewController，没有的话才可以present

if ([UIApplication sharedApplication].delegate.window.rootViewController.presentedViewController == nil) {    [[UIApplication sharedApplication].delegate.window.rootViewController presentViewController:self.gesturePasswordController animated:YES completion:^{            }];}