滑动视图时NavigationBarItem重叠

置导航条上可视元素背景颜色方法：

    /// 1.1 设置Bar背景颜色 以及默认BarItem的颜色

    [self.navigationBar setBarTintColor:RGBCOLOR_HEX(0xf95900)];

    [self.navigationBar setTintColor:[UIColor whiteColor]];

    /// 1.2全局设置

    UINavigationBar.appearance().barTintColor = UIColor(red: 242.0/255.0, green: 116.0/255.0, blue: 119.0/255.0, alpha: 1.0)

    UINavigationBar.appearance().tintColor = UIColor.whiteColor()

1. 设置导航条上的 字体颜色方法

    /// 2.1 设置导航条上的字体颜色

    NSDictionary *attributes = [NSDictionary dictionaryWithObjectsAndKeys:[UIColor whiteColor],NSForegroundColorAttributeName,[UIFont systemFontOfSize:24],NSFontAttributeName, nil];

    [self.navigationBar setTitleTextAttributes:attributes];

    /// 2.2 全局设置方法

    if let barFont = UIFont(name: "Avenir-Light", size: 24.0) {

    UINavigationBar.appearance().titleTextAttributes = [NSForegroundColorAttributeName:UIColor.whiteColor(), NSFontAttributeName:barFont]

1. iOS 7 之后，导航条默认的半透明状态设置

    /// 如果是YES， 默认状态是YES VC的子视图的y_0点将默认可视区域上移44，改为NO之后，VC的姿势图的y_0点将是导航条的y_0点。

    [self.navigationBar setTranslucent:YES];

1. 取消Push子视图默认返回导航BackItem的文字

        ///注意：VC_A.nav pushTo VC_B  那么代码需要写在VC_A中。

        navigationItem.backBarButtonItem = UIBarButtonItem(title: "", style: .Plain, target: nil, action: nil)

        self.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"" style:UIBarButtonItemStylePlain target:nil action:nil];

1. iOS 8 之后，导航控制器之间，在滑动导航时候隐藏导航条（“Hiding a Navigation Bar on Swipe）

        override func viewWillAppear(animated: Bool) {

            super.viewWillAppear(animated)

            navigationController?.hidesBarsOnSwipe = false

            navigationController?.setNavigationBarHidden(false, animated: true)

        }

1. iOS 7，可以为每一个VC 单独更改状态栏样式

        /// 只需要在VC.m 中实现方法

        override func preferredStatusBarStyle() -> UIStatusBarStyle {

            return .LightContent

        }

        /// 也可以全局的设置 两种方法  首先是代码

        UIApplication.sharedApplication().statusBarStyle = .LightContent

        /// 然后是plist文件修改：

        Under the Info tab of the OBJect target, insert a new key named View controller-based status bar appearance and set the value to NO

1. 自己添加一个UIBarButtomItem

        ///直接上代码

        @class CNBarButtonItem;

        typedef void(^BBIBlock)(CNBarButtonItem *barBItem);

        @interface CNBarButtonItem : UIBarButtonItem

        - (instancetype)barMenuButtomItem;

        - (instancetype)barButtomItem:(NSString *)title;

        - (void)barBlock:(BBIBlock )thisBlock;

        ========.h   下面是实现文件 -->.m

        @implementation CNBarButtonItem{

            BBIBlock _bbiBlock;

        }

        - (instancetype)barButtomItem:(NSString *)title {

            UIButton *itemButton = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 60, 40)];

            [itemButton addTarget:self action:@selector(barItemEvent:) forControlEvents:UIControlEventTouchUpInside];

            [itemButton setTitle:title forState:UIControlStateNormal];

            [itemButton setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];

            itemButton.size = [self sizeOfBtn:itemButton];

            return  [self initWithCustomView:itemButton];

        }

        - (CGSize)sizeOfBtn:(UIButton *)btn

        {

            CGSize sizeBtn = [btn.titleLabel sizeThatFits:CGSizeMake(100,30)];

            CGSize sizeReal    = CGSizeMake(sizeBtn.width + 10, 40);

            CGSize minSize     = CGSizeMake(40, 40);

            CGSize lastSize    = sizeBtn.width + 10  > 40 ? sizeReal : minSize;

            return lastSize;

        }

        - (void)barItemEvent:(UIButton *)btn {

            if (_bbiBlock) {

                _bbiBlock(self);

            }

        }

        - (void)barBlock:(BBIBlock)thisBlock {

            _bbiBlock = thisBlock;

        }

        =================DestVC_中使用如下

        CNBarButtonItem *editItem = [[CNBarButtonItem alloc] barButtomItem:@"Edit"];

        [editItem barBlock:^(CNBarButtonItem *barBItem) {

            NSLog(@"Edit Click");

            //        [self showChannelSetView];

            self.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"" style:UIBarButtonItemStylePlain target:nil action:nil];

            CNNewsDetailViewController *_newsDetail = [[CNNewsDetailViewController alloc] init];

            [self.navigationController pushViewController:_newsDetail animated:YES];

        }];

        UIBarButtonItem *rightSpaceItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFixedSpace target:nil action:nil];

        rightSpaceItem.width =  iPhone6Plus? -15:-8;

        self.navigationItem.rightBarButtonItems = @[rightSpaceItem,editItem];