在系统方法中调用navigationController的标准写法
-(void)viewWillAppear:(BOOL)animated{
[super viewWillAppear:animated];
if (self.navigationController) {
self.navigationController.navigationBarHidden = YES;
}
}
1.[super viewWillAppear:animated];
2.
if (self.navigationController) {
3. self.navigationController.navigationBarHidden = YES;
}