objective-c - 如何使用自定义 UINavigationBar

Question

我有UINavigationBar.

@interface MyNavigationBar : UINavigationBar

进行了一些更改，现在希望我的应用程序NavigationController可以使用它：

 _navigationController = [[UINavigationController alloc] initWithRootViewController:self.viewController];
 [_window addSubview:[_navigationController view]];
[self.window makeKeyAndVisible];

我希望 _ navigationController有MyNavigationBar

怎么可能做到这一点？

谢谢。

Answer 1

您必须创建一个带有 a 的 xib UINavaigationController。然后，您可以navigationBar在 Interface Builder 中选择 并将类更改为UINavigationBar.

然后为了更容易实例化，我向 `UINavigationController 添加了一个类别，例如：

@interface UINavigationController (DSCNavigationController)

+ (UINavigationController *)dsc_navigationControllerWithRootViewController:(UIViewController *)rootViewController;

@end

@implementation UINavigationController (DSCNavigationController)

+ (UINavigationController *)dsc_navigationControllerWithRootViewController:(UIViewController *)rootViewController;
{
    NSArray *topLevelObjects = [[NSBundle mainBundle] loadNibNamed:@"DSCNavigationController" owner:nil options:nil];

    NSAssert(1 == [topLevelObjects count], @"DSCNavigationController should have one top level object");

    UINavigationController *navigationController = [topLevelObjects objectAtIndex:0];

    NSAssert([navigationController isKindOfClass:[UINavigationController class]], @"Should have a UINavigationController");

    [navigationController pushViewController:rootViewController animated:NO];

    return navigationController;
}

@end

在使用它的类的顶部，确保在我的情况下导入类别，它看起来像

#import "UINavigationController+DSCNavigationController"

然后使用它看起来像

MyViewController *myViewController = [[MyViewController  alloc] init];
UINavigationController *navigationController = [UINavigationController dsc_navigationControllerWithRootViewController:myViewController];

Answer 2

UINavigationController 具有只读属性

@property(nonatomic, readonly) UINavigationBar *navigationBar

因为它是只读的，所以您必须继承 UINavigationBar 并覆盖此属性或使其为 read-write.Eg ：

MyNaviagtionBar *myBar = [[MyNavigationBar alloc] init];
_navigationController.navigationBar = mybar;

或子类化：

我的导航控制器.h

@class MyNavigationBar;

@interface MyNavigationController : UINavigationController
@property(nonatomic, strong) MyNavigationBar *navigationBar;
@end

我的导航控制器.m

@implementation MyNavigationController
@synthesize navigationBar = _navigationBar;
@end

然后改变

_navigationController = [[UINavigationController alloc] initWithRootViewController:self.viewController];

至

_navigationController = [[MyNavigationController alloc] initWithRootViewController:self.viewController];