以编程方式将 UINavigationBar 添加到 UIView？

Question

我正在尝试以编程方式将 UINavigationBar 添加到 UIView 并取得了如此成功，但无法弄清楚。我正在尝试将它添加到我的 UIView 子类中，但当我运行我的应用程序时它根本没有显示出来。

这是我的代码：

UINavigationBar *navBar = [[UINavigationBar alloc] initWithFrame:CGRectMake(0, 0, self.frame.size.width, headerHeight)];
    [navBar setBackgroundColor:[UIColor blueColor]];
    [self addSubview:navBar];

    UIBarButtonItem *doneItem = [[UIBarButtonItem alloc] initWithTitle:@"done" style:UIBarButtonItemStylePlain target:self action:@selector(done:)];

    UINavigationItem *navItem = [[UINavigationItem alloc] initWithTitle:@"categories"];
    [navItem setRightBarButtonItem:doneItem animated:YES];
    [navBar setItems:[NSArray arrayWithObject:navItem] animated:YES];

Answer 1

如果您从第一个视图中使用导航控制器，我建议您在 Appdelegate.m 中这样做

 UIViewController *viewController = [[MenuViewController alloc] initWithNibName:@"FirstViewController" bundle:nil];
        UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:viewController]; 
        self.window.rootViewController=navController;

但是，如果您有一个显示新视图的视图，并且您想要一个导航栏，请使用它来显示新视图：

UIViewController *viewController = [[MenuViewController alloc] initWithNibName:@"MenuViewController" bundle:nil];
            UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:viewController]; 
[self presentViewController:navigationcontroller animated:YES completion:nil];

然后您可以在第二个视图中添加您的 navBarButtons，如下所示：

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

        UIBarButtonItem *btnAdd = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(btnAddGroupPressed)];
        self.navigationItem.rightBarButtonItem=btnAdd;

    }
    return self;
}

Answer 2

我不确定发生了什么。这是我用来重现您的问题的代码：

*.h 文件为空

#import "STTestView.h"

@implementation STTestView

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code

        UINavigationBar *navBar = [[UINavigationBar alloc] initWithFrame:CGRectMake(0, 0, 300, 50)];
        navBar.barTintColor = [UIColor purpleColor];
        [self addSubview:navBar];

        UIBarButtonItem *doneItem = [[UIBarButtonItem alloc] initWithTitle:@"done" style:UIBarButtonItemStylePlain target:self action:@selector(done:)];

        UINavigationItem *navItem = [[UINavigationItem alloc] initWithTitle:@"categories"];
        [navItem setRightBarButtonItem:doneItem animated:YES];
        [navBar setItems:[NSArray arrayWithObject:navItem] animated:YES];

        self.backgroundColor = [UIColor darkGrayColor];
    }
    return self;
}

-(void)done:(id)sender {

}

@end

这就是我得到的：

请问：

1. 为整个initWithFrame:方法添加代码？
2. 确保在代码运行时 self.frame 和 headerHeight 实际上设置正确？
3. 记住不要使用backgroundColor 属性，而是使用barTintColor 属性

希望这会有所帮助！

Answer 3

我不能告诉你为什么，但我遇到了同样的问题，我追踪到了setBackgroundColor 方法。为了解决这个问题，我做了：

UINavigationBar *navBar = [[UINavigationBar alloc] initWithFrame:CGRectMake(0, 0, screenWidth, 44.0)];
UINavigationItem *titleItem = [[UINavigationItem alloc] initWithTitle:@"MyNavBar"];
NSDictionary *titleAttributesDictionary =  [NSDictionary dictionaryWithObjectsAndKeys:
                                            [UIColor whiteColor],
                                            UITextAttributeTextColor,
                                            [UIColor colorWithRed:0.0 green:0.0 blue:0.0 alpha:0],
                                            UITextAttributeTextShadowColor,
                                            [NSValue valueWithUIOffset:UIOffsetMake(0, -1)],
                                            UITextAttributeTextShadowOffset,
                                            [UIFont fontWithName:@"HelveticaNeue-Light" size:20.0],
                                            UITextAttributeFont,
                                            nil];
navBar.titleTextAttributes = titleAttributesDictionary;
navBar.items = @[titleItem];
navBar.tintColor=[UIColor blueColor];
[self addSubview:navBar];

Answer 4

也许，您忘记了“navBar.items = @[navItem];”因为我处理了类似的问题：

    UINavigationBar *navBar = [[UINavigationBar alloc] initWithFrame:CGRectMake(0, 0, self.frame.size.width, headerHeight)];
    navBar.barTintColor = [UIColor blueColor];
    [self addSubview:navBar];//it is important point, otherwise, you can see only the area without any item

    UIBarButtonItem *doneItem = [[UIBarButtonItem alloc] initWithTitle:@"done" style:UIBarButtonItemStylePlain target:self action:@selector(done:)];

    [navItem setRightBarButtonItem:doneItem animated:YES];
    [navBar setItems:[NSArray arrayWithObject:navItem] animated:YES];

使用这些属性：“barTintColor”获取导航栏背景颜色，“tintColor”获取导航项和栏按钮项。

Answer 5

如果您使用的是 xib 而不是情节提要，请在 AppDelegate 中编写这些行：

UIViewController *viewControllerObj = [[MenuViewController alloc] initWithNibName:@"FirstViewController" bundle:nil];
UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:viewControllerObj]; 
self.window.rootViewController=navController;

如果您使用的是故事板，那么最好从菜单中添加 NavigationController。