如何使用自定义背景图像从 UINavigationBar 和 UIToolbar 中删除圆角？答案

【问题标题】：How to remove rounded corners from UINavigationBar and UIToolbar with custom background images?如何使用自定义背景图像从 UINavigationBar 和 UIToolbar 中删除圆角？
【发布时间】：2011-08-15 16:40:56
【问题描述】：

在基于拆分视图的 iPad 应用程序中，我在导航栏和工具栏中使用自定义背景图像。我对UINavigationBar 和/或UIToolbar 进行了子类化，在drawRect: 我有（背景图像是矩形）：

- (void)drawRect:(CGRect)rect {
    CGContextRef c = UIGraphicsGetCurrentContext();
    UIImage *image = [UIImage imageNamed:@"background-image"];    

    CGContextDrawImage(c, rect, image.CGImage);
}

结果是我想从中删除圆角。

我已经尝试过的：

[image drawInRect:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];结果和上面一样，
clipsToBounds = YES; 在我的子类中，
cornerRadius=0.0,
iPhoneOS SDK - Remove Corner Rounding from views (iPad problem)

4. 中描述的问题与我遇到的完全相同。不幸的是，该问题中描述的解决方案对我不起作用。当从viewWillAppear 在纵向方向调用时，它出于某种原因隐藏了我的导航项。在 Landscape 中从 didRotateFromInterfaceOrientation: 调用时，圆角消失了，但同时所有用户交互都被禁用。此外，当旋转回纵向时，我的“主”视图（拆分视图的左侧）不会隐藏。

我使用接受答案中的代码得到的输出是：

aView: <UIWindow: 0x5e18470; frame = (0 0; 768 1024); opaque = NO; autoresize = RM+BM; layer = <CALayer: 0x5e18280>>
subview: <UILayoutContainerView: 0x6942000; frame = (20 0; 748 1024); transform = [0, -1, 1, 0, 0, 0]; autoresize = W+H; layer = <CALayer: 0x6946b30>>
aView: <UILayoutContainerView: 0x6942000; frame = (20 0; 748 1024); transform = [0, -1, 1, 0, 0, 0]; autoresize = W+H; layer = <CALayer: 0x6946b30>>
subview: <BackgroundImageView: 0xbbacf70; frame = (0 0; 768 1004); layer = <CALayer: 0xbbad020>>
aView: <BackgroundImageView: 0xbbacf70; frame = (0 0; 768 1004); layer = <CALayer: 0xbbad020>>
subview: <UILayoutContainerView: 0x69144e0; frame = (321 0; 703 748); clipsToBounds = YES; layer = <CALayer: 0x6946fe0>>
aView: <UILayoutContainerView: 0x69144e0; frame = (321 0; 703 748); clipsToBounds = YES; layer = <CALayer: 0x6946fe0>>
subview: <UILayoutContainerView: 0xbbabc40; frame = (0 0; 320 748); clipsToBounds = YES; layer = <CALayer: 0xbbabc90>>
aView: <UILayoutContainerView: 0xbbabc40; frame = (0 0; 320 748); clipsToBounds = YES; layer = <CALayer: 0xbbabc90>>
subview: <UIImageView: 0x5e178c0; frame = (321 0; 3 3); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0xba60d10>> - (null)
aView: <UIImageView: 0x5e178c0; frame = (321 0; 3 3); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0xba60d10>> - (null)
subview: <UIImageView: 0xba74010; frame = (317 0; 3 3); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0xba62180>> - (null)
aView: <UIImageView: 0xba74010; frame = (317 0; 3 3); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0xba62180>> - (null)
subview: <UIImageView: 0xbad0110; frame = (321 745; 3 3); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0xba60da0>> - (null)
aView: <UIImageView: 0xbad0110; frame = (321 745; 3 3); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0xba60da0>> - (null)
subview: <UIImageView: 0xba60e00; frame = (317 745; 3 3); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0xba60e30>> - (null)
aView: <UIImageView: 0xba60e00; frame = (317 745; 3 3); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0xba60e30>> - (null)

还有一些小的 3x3px 圆角 UIImageViews。

问题是：如何去除那些微小的圆角？

【问题讨论】：

这个运气好吗？目前我自己也遇到了同样的问题。

标签： cocoa-touch uinavigationbar uisplitviewcontroller uitoolbar rounded-corners

【解决方案1】：

对我有用的解决方案：

- (void)hideSplitViewCorners {
// Hide corners of splitview.
NSMutableArray *views = [NSMutableArray array];
[views addObject:[self view]];

for (NSUInteger i = 0; i < views.count; ++i) {
    UIView *view = [views objectAtIndex:i];
    [views addObjectsFromArray:view.subviews];

    if (view.frame.size.width == 3.0 && view.frame.size.height == 3.0) {
        view.hidden = YES;
    }
  }    
}

我在 UISplitViewController 的子类的 loadView 和 didRotateFromInterfaceOrientation: 中调用它。请注意，在后者中我需要使用[self performSelector:@selector(hideSplitViewCorners) withObject:NULL afterDelay:0];。

基本上，需要确保这些角的隐藏是在它们已经显示在屏幕上之后完成的。

【讨论】：