一般隱藏和顯示導航欄蹬昌，只要在基類如下寫就好：
-(BOOL)needHiddenNavigationBar:(UIViewController *)vc{
BOOL isHidden = NO;
if ([NSStringFromClass([vc class]) isEqualToString:@"ViewController"]||
[NSStringFromClass([vc class]) isEqualToString:@"ViewController_1"]) {
isHidden = YES;
}
return isHidden;
}
-(void)viewWillAppear:(BOOL)animated{
[super viewWillAppear:animated];
[self.navigationController setNavigationBarHidden:[self needHiddenNavigationBar:self] animated:animated];
}
但當在一種特殊情況下蛤肌，就是在第一第二個控制器隱藏導航欄時，當在第二控制器右滑一點點在回來時在第四個控制器會還是會出現(xiàn)導航欄混亂的情況女轿。
-(void)viewDidAppear:(BOOL)animated{
[super viewDidAppear:animated];
NSLog(@"\n%@==%@",NSStringFromClass([self class]),self.navigationController.navigationBar.items);
NSLog(@"\n%@==%@",NSStringFromClass([self class]),self.navigationController.viewControllers);
}```
結果為：
2017-04-23 14:22:15.810 導航欄[2008:53347]
ViewController_3==(
"<<UINavigationItem: 0x6000001cbb80>: title:'ViewController'>",
"<<UINavigationItem: 0x6080001cbe50>: title:'ViewController_1'>",
"<<UINavigationItem: 0x6080001cc030>: title:'ViewController_2'>"
)
2017-04-23 14:22:15.811 導航欄[2008:53347]
ViewController_3==(
"<ViewController: 0x7fc822103a80>",
"<ViewController_1: 0x7fc8206056c0>",
"<ViewController_2: 0x7fc820510040>",
"<ViewController_3: 0x7fc820615db0>"
)```
少一個item 我偶然看到支付寶也出現(xiàn)此現(xiàn)象 他的做法是在添加一個item贪染。
-(void)viewDidAppear:(BOOL)animated{
[super viewDidAppear:animated];
NSLog(@"\n%@==%@",NSStringFromClass([self class]),self.navigationController.navigationBar.items);
NSLog(@"\n%@==%@",NSStringFromClass([self class]),self.navigationController.viewControllers);
if (self.navigationController.navigationBar.topItem != self.navigationItem && ![self needHiddenNavigationBar:self]) {
[self.navigationController setNavigationBarHidden:YES animated:animated];
[self.navigationController setNavigationBarHidden:NO animated:animated];
}
}
這樣就可以了，圖
