Question

我是UINavigationBar的子类。在我的导航栏中，我想添加一个后退按钮。最终我想要一个标题自定义按钮和uicollectionview看起来像这样：

我在UINavigationBar

的子类中添加按钮时遇到问题

的AppDelegate：

 NFVDContentTableViewController *contentTVC = [[NFVDContentTableViewController alloc] initWithNibName:nil bundle:nil];
 UINavigationController *contentNavCtr = [[UINavigationController alloc] initWithNavigationBarClass:[NFVDContentNavigationBar class] toolbarClass:[UIToolbar class]];
 contentNavCtr.viewControllers = @[contentTVC];

在我的子类UINavigation标头文件中：

@interface NFVDContentNavigationBar : UINavigationBar <UINavigationBarDelegate>

@end

在我的子类UINavigationBar实现文件中：

@implementation NFVDContentNavigationBar

/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect {
    // Drawing code
}
*/

- (instancetype)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {

    }
    return self;
}

- (void)awakeFromNib {

    [super awakeFromNib];

    UINavigationItem* ni = [[UINavigationItem alloc] init];
    UIButton *leftButton = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 38.0f, 29.0f)];
    [leftButton setImage:[UIImage imageNamed:@"reveal-icon"] forState:UIControlStateNormal];
    [leftButton addTarget:nil action:@selector(menuItemPressed:) forControlEvents:UIControlEventTouchUpInside];
    [leftButton setContentMode:UIViewContentModeScaleAspectFit];
    [leftButton setAutoresizingMask:UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleTopMargin];
    UIBarButtonItem *b =[[UIBarButtonItem alloc] initWithCustomView:leftButton];

    ni.leftBarButtonItem = b;
    self.items = @[ni];

}

- (CGSize)sizeThatFits:(CGSize)size{

    CGSize newSize = [super sizeThatFits:size];

    DLog(@"NewSize: %@", NSStringFromCGSize(newSize));

    CGRect mainScreen = [UIScreen mainScreen].bounds;

    if([UIView viewOrientationForSize:mainScreen.size] == ViewOrientationPortrait){

        return CGSizeMake(newSize.width, 100);

    }else if([UIView viewOrientationForSize:mainScreen.size] == ViewOrientationLandscape){

        return CGSizeMake(newSize.width, 44);

    }

    return CGSizeZero;

}

- (void)layoutSubviews {
    [super layoutSubviews];
}

@end

Answer 1

这很难做到，因为UIViewController带有自己的UINavigationItems，请参阅UIViewController头文件中的文档：

NS_CLASS_AVAILABLE_IOS(2_0) @interface UIViewController : UIResponder <NSCoding, UIAppearanceContainer, UITraitEnvironment, UIContentContainer> {
    @package
    UIView           *_view;
    UITabBarItem     *_tabBarItem;
    UINavigationItem *_navigationItem;

您必须覆盖UIViewController的这个功能，这是可能的，但要求您继承UIViewController，然后强制app中的所有视图控制器成为子类视图控制器的子类，这样就很难了方式，我会显示它的代码，但它有点强烈和很多代码，但这就是我这样做的方式。无论如何，更好的选择是在你的UIViewController的ViewDidLoad中执行此操作：

- (void)viewDidLoad
{
    [super viewDidLoad];
    UIBarButtonItem * tester = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"reveal-icon"] style:UIBarButtonItemStylePlain target:self action:@selector(menuItemPressed:)];
    [[self navigationItem] setRightBarButtonItem:tester];
}

你仍然可以继承UINavigationBar的子类，但是不要将它作为子类来尝试覆盖已经挂钩到UIKit默认的UIViewController的barbuttonitems，如果你想对此有所了解，那么这里＆＃39;是你如何继承UIViewController的开始，它有很多代码：

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];

    if (self == nil)
        return nil;

    if (self) {
        _showsNotifications = false;
        _showsAddFriends = false;
    }
    _notificationsBarButtonItem = [[UIBarButtonItem alloc] initWithImage:[UIImage resizeImage:[UIImage imageNamed:@"YOUR IMAGE NAME"] height:27] style:UIBarButtonItemStylePlain target:nil action:nil];
    _addFriendsBarButtonItem = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"YOUR IMAGE NAME"] style:UIBarButtonItemStylePlain target:self action:@selector(addFriendsPressed)];
}

您会看到，您添加到自定义视图控制器Bool属性，这些属性会更改UIViewController中UINavigationItem的内部结构。使用此方法然后需要您在作为此自定义viewcontroller的子类的viewcontrollers的INIT中调用和设置这些bool值，如下所示：

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self)
    {
        [self setShowsAddFriends:false];
        [self setShowsNotifications:false];
    }
    return self;
}

然后在子类UIViewController中，使bool开关能够实际切换。

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];

    if (_showsNotifications) {
        [[self navigationItem] setRightBarButtonItem:_notificationsBarButtonItem];
    }
    if (_showsAddFriends) {
        [[self navigationItem] setRightBarButtonItem:_addFriendsBarButtonItem];
    }
}

完成并完成，复杂吗？排序，但这是你如何使用尽可能多的自定义导航项目按钮模板项目，完整的代码大约是1k行代码，但这是它的内核，子类UIViewController，在头文件中设置bool属性，设置这些您的子类中的bool属性，以便使用此子类作为其父类的UIViewControllers可以在＆＃34; init＆＃34;中调用这些bool setter属性，然后您将能够切换并选择您喜欢的任何导航项。此外，为了确保视图控制器维护您设置的项目，请确保在视图控制器中的viewWillAppear中声明这些项目设置，这些视图控制器使用UIViewController的自定义子类作为父视图。祝你好运，祝你有个美好的一天。

事实上，我只会告诉你代码，为什么？因为我很无聊，下周有两个应用程序发布太多了。所以，这里是您需要查看的文件，请记住这些文件非常简化：

CCUSTViewController.m

//******CCUSTViewController.m****
//this is the implementation file for the subclass of UIViewController

#import "CCUSTViewController.h"
#import "CCUSTFriendsViewController.h"
#import "CCUSTActivitiesViewController.h"

@interface CCUSTViewController ()
@end

@implementation CCUSTViewController
{
    UIBarButtonItem * _notificationsBarButtonItem;
    UIBarButtonItem * _addFriendsBarButtonItem;
}

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self == nil)
        return nil;
    if (self) {
        _showsNotifications = false;
        _showsAddFriends = false;
    }
    _notificationsBarButtonItem = [[UIBarButtonItem alloc] initWithImage::[UIImage imageNamed:@"your imate"] style:UIBarButtonItemStylePlain target:self action:@selector(showNotificationsPressed)];
    _addFriendsBarButtonItem = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"your imate"] style:UIBarButtonItemStylePlain target:self action:@selector(addFriendsPressed)];
    return self;
}
- (void)showNotificationsPressed
{
    CCUSTActivitiesViewController * tobePushed = [CCUSTActivitiesViewController new];
    [self navigationController] pushViewController:tobePushed animated:true];
}

- (void)addFriendsPressed
{
    CCUSTFriendsViewController * tobePushed = [CCUSTFriendsViewController new];
    [self navigationController] pushViewController:tobePushed animated:true];
}

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    if (_showsNotifications) {
        [[self navigationItem] setRightBarButtonItem:_notificationsBarButtonItem];
    }
    if (_showsAddFriends) {
        [[self navigationItem] setRightBarButtonItem:_addFriendsBarButtonItem];
    }
}

@end

CCUSTViewController.h

#import <UIKit/UIKit.h>

@interface CCUSTViewController : UIViewController

@property (nonatomic) BOOL showsNotifications;
@property (nonatomic) BOOL showsAddFriends;

@end

然后，这是使用新导航栏项目切换器的子类View控制器的示例：

CCCUSTHomeViewController.h

#import "CCUSTViewController.h"

@interface CCCUSTHomeViewController : CCUSTViewController
@end

CCCUSTHomeViewController.m

// CCCUSTHomeViewController.m
#import "CCCUSTHomeViewController.h"
#import "CCCUSTHomeView.h"

@interface CCCUSTHomeViewController () 
@end

@implementation CCCUSTHomeViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self)
    {
        [self setShowsAddFriends:TRUE];
        [self setShowsNotifications:TRUE];
    }
    return self;
}

-(void)loadView 
{
    [self setView:[CCCUSTHomeView new]];
}

-(CCCUSTHomeView*)contentView 
{
    return (id)[self view];
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    [self setTitle:@"HOME"];
}

-(void)viewWillAppear:(BOOL)animated 
{
    [super viewWillAppear:animated];
    [self setShowsAddFriends:TRUE];
    [self setShowsNotifications:TRUE];
}
@end

哦，是的，您需要将相同的代码从init添加到ViewWillAppear，因为当您在堆栈上弹出推送的视图控制器时，您甚至需要在CCCUSTHomeViewController中拦截它，以便UINavigationItems重新出现，因为它们是应该给出位于堆栈顶部的viewcontroller。您也可以使用相同的方法将UICollectionViewController和UITableViewController中的所有内容子类化，这意味着使用此结构作为模板，您可以在Xcode中添加一个空项目，并添加所有这些子类，然后您可以更好地控制所有视图控制器。你可以用更多的方法来实现这种方法，但有些事情，我必须保守秘密，但足以说明，许多大型应用程序使用相同的技术和你赢得的其他先进技术＃39; t在野外看到。巧妙的是，你不必委托，而且你不会操纵任何东西。祝你好运，祝你有个美好的一天。

GISTS因为我关心：

https://gist.github.com/anonymous/993e457561001cf8e77b

https://gist.github.com/anonymous/bc6095575038c36de77b

https://gist.github.com/anonymous/78b450d2a805781ab8a4

https://gist.github.com/anonymous/a0757179c17dd7078bb2

将按钮添加到UINavigationBar的子类

1 个答案: