垂直对齐UINavigationItems

Question

我已将UINavigationBar的高度自定义为100px，我想在此自定义栏上添加按钮。

一切都很好，除了按钮似乎想要坐在导航栏的底部，无论如何。我不能让它与导航栏的中心或顶部对齐。

这是代码;首先，我在app delegate中创建一个导航控制器，并在右侧添加一个按钮。

// set main navigation controller
temp *tempc = [[temp alloc] initWithNibName:@"temp" bundle:nil];
self.navigationController = [[UINavigationController alloc] initWithRootViewController:tempc];

UIBarButtonItem *navItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:nil action:nil];

[tempc.navigationItem setRightBarButtonItem:navItem];
[self.window addSubview:self.navigationController.view];
[self.window makeKeyAndVisible];

然后我在“temp”视图控制器中调整导航栏的大小，如下所示：

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
    CGRect frame = CGRectMake(0.0f, 0.0f, 320.0f, 100.0f);
    [self.navigationController.navigationBar setFrame:frame];
    [self.navigationController.navigationBar setAutoresizingMask:UIViewAutoresizingFlexibleBottomMargin];
}

我还尝试向rightBarButtonItem添加自定义视图，但我无法将添加的自定义视图完全触及顶部。

这次不幸的尝试的代码：

// set main navigation controller
temp *tempc = [[temp alloc] initWithNibName:@"temp" bundle:nil];
self.navigationController = [[UINavigationController alloc] initWithRootViewController:tempc];

UIView *customView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 36.0f, 80.0f)];
[customView setBackgroundColor:[UIColor blueColor]];

UIButton *customButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[customButton setFrame:CGRectMake(0, 22.0f, 36.0f, 36.0f)];
[customButton setTitle:@"+" forState:UIControlStateNormal];

[customView addSubview:customButton];
UIBarButtonItem *customItem = [[UIBarButtonItem alloc] initWithCustomView:customView];

有没有人知道如何在UINavigationBar上垂直对齐UIBarButtonItem？

Answer 1

这会将页面标题和所有按钮向上移动20 px：

[[UINavigationBar appearance] setTitleVerticalPositionAdjustment:-20.0 forBarMetrics:UIBarMetricsDefault];
[[UIBarButtonItem appearance] setBackgroundVerticalPositionAdjustment:-20.0 forBarMetrics:UIBarMetricsDefault];

Answer 2

如果您只有rightBarButtonItem而没有留下，则来自alhcr（选项1）的当前接受的答案不起作用。它还对UINavigationBar的子视图排序做出了一个假设，这个假设并不能得到保证，并且在未来的iOS版本中可以很好地改变。这是一种更好的自定义导航按钮框架的方法：

// UINavigationBar subclass

- (void)layoutSubviews {

    [super layoutSubviews];

    UINavigationItem *navigationItem = [self topItem];

    for (UIView *subview in [self subviews]) {

        if (subview == [[navigationItem rightBarButtonItem] customView]) {

            CGRect newRightButtonRect = CGRectMake(...new rect...);
            [subview setFrame:newRightButtonRect];
        }
        else if (subview == [[navigationItem backBarButtonItem] customView]) {

            CGRect newBackButtonRect = CGRectMake(...new rect...);
            [subview setFrame:newBackButtonRect];
        }
    }
}

Answer 3

选项1：

• 创建UINavigationBar子类
• 在此类内部覆盖- (void)layoutSubviews，您将在其中重新定位UIBarButtonItems
Interface Builder中的
• 将UINavigationBar类设置为UINavigationBar子类

示例：

UINavigationBar的子类内部：

- (void)layoutSubviews {
    int index = 0;
    for ( UIButton *button in [self subviews] ) {
        if(index == 1) {
            [button setFrame:CGRectMake(5,40,60,40)]; //leftBarButtonItem
        } else if(index == 2) {
            [button setFrame:CGRectMake(275,40,40,40)]; //rightBarButtonItem
        }
        ++index;
    }
}

查看控制器：

- (void)viewDidLoad {
...
    UIBarButtonItem *navItem1 = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:nil action:nil];
    UIBarButtonItem *navItem2 = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemCancel target:nil action:nil];
    [self.navigationItem setRightBarButtonItem:navItem1];   
    [self.navigationItem setLeftBarButtonItem:navItem2];

    CGRect frame = CGRectMake(0.0f, 0.0f, 320.0f, 100.0f);
    [self.navigationController.navigationBar setFrame:frame];
...
}

选项2（插入UIBarButtonItem不起作用）：

UINavigationBar *navigationBar = [[UINavigationBar alloc] initWithFrame:CGRectMake(0,0,320,100)];
[self.view addSubview:navigationBar];

UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[button setFrame:CGRectMake(0,25,50,50)];
[navigationBar addSubview:button];

Answer 4

我通过在自定义按钮的图像边缘插入中进行调整找到了此问题的解决方案。我在应用程序中有要求增加导航栏的高度，并且在增加高度后使rightBarButtonItem和leftBarButtonItem图像处于未定位的问题。

找到以下代码： -

UIImage *image = [[UIImage imageNamed:@"searchbar.png"];
UIButton* searchbutton = [UIButton buttonWithType:UIButtonTypeCustom];
[searchbutton addTarget:self action:@selector(searchBar:) forControlEvents:UIControlEventTouchUpInside]; 
searchbutton.frame = CGRectMake(0,0,22, 22);
[searchbutton setImage:image forState:UIControlStateNormal];
[searchbutton setImageEdgeInsets:UIEdgeInsetsMake(-50, 0,50, 0)];
// Make BarButton Item
 UIBarButtonItem *navItem = [[UIBarButtonItem alloc] initWithCustomView:searchbutton];
self.navigationItem.rightBarButtonItem = navItem;