只需为包含两个按钮的右侧导航按钮使用自定义 UIView 即可。
您可以使用直接的方法来创建显示为右侧导航按钮项的自定义 UIView。此 UIView 应包含您要在其间翻转的两个 UIButton。请记住,UIButton 也是 UIView,因此它们可以使用与普通 UI 视图可以翻转的相同转换来翻转,当然它们也可以被点击!这是一些有效的示例代码:
注意:我使用便利功能将按钮创建为 UIViewController 的自定义类别(注意:您也可以添加相同的代码来为 UIView 创建自定义类别,只需复制相同的行并将 UIViewController 替换为 UIView) - 如果你想也可以使用它,只需通过在下面包含此代码来创建自定义类别,或者您可以像往常一样创建 UIButtons。
// create custom category for UIViewController to allow common button creation routine, add to .m or .mm file or add to a .h file and #import that .h file
@interface UIViewController (ButtonAndSelector)
- (UIButton *)createUIButtonWithImage:(UIImage *)image forState:(UIControlState)state withSelector:(SEL)selector usingFrame:(CGRect)buttonImageFrame;
@end
@implementation UIViewController (ButtonAndSelector)
- (UIButton *)createUIButtonWithImage:(UIImage *)buttonImage forState:(UIControlState)state withSelector:(SEL)selector usingFrame:(CGRect)buttonImageFrame
{
UIButton *button = [[UIButton alloc] initWithFrame:buttonImageFrame];
[button setBackgroundImage:buttonImage forState:state];
[button addTarget:self action:selector forControlEvents:UIControlEventTouchUpInside];
[button setShowsTouchWhenHighlighted:YES];
return button;
}
@end
// add this to your .h file:
@property (strong, nonatomic) UIView *coverListView;
@property (strong, nonatomic) UIButton *listButton;
@property (strong, nonatomic) UIButton *coverButton;
- (void)animateCoverListButtonFlip;
// add this to your .m or .mm file to synthesize the variables:
@synthesize coverListView;
@synthesize listButton;
@synthesize coverButton;
// add this to your .m or .mm file in the viewDidLoad:
// setup right button bar (flips between list icon and coverart image)
self.coverListView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 32, 30)];
self.coverListView.backgroundColor = [UIColor clearColor];
self.coverListView.opaque = NO;
self.listButton = [self createUIButtonWithImage:[UIImage imageNamed:@"navbar_icon_tracklisting"] forState:UIControlStateNormal withSelector:@selector(showHideQueue) usingFrame:CGRectMake(0, 0, 32, 30)];
self.listButton.backgroundColor = [UIColor clearColor];
self.listButton.showsTouchWhenHighlighted = NO;
self.coverButton = [self createUIButtonWithImage:[UIImage imageNamed:@"default_coverart_small"] forState:UIControlStateNormal withSelector:@selector(showHideQueue) usingFrame:CGRectMake(0, 0, 32, 30)];
[self.coverListView addSubview:self.coverButton]; // show coverButton by default
self.coverButton.showsTouchWhenHighlighted = NO;
UIBarButtonItem *barButtonItem = [[UIBarButtonItem alloc] initWithCustomView:self.coverListView];
[self.navigationItem setRightBarButtonItem:barButtonItem];
// add this to viewDidAppear if you want to flip the button when the screen appears like the build in iPod app does
[self animateCoverListButtonFlip];
// add this routine to flip the right navigation bar custom view / buttons
- (void)animateCoverListButtonFlip
{
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.75];
[UIView setAnimationTransition:([self.listButton superview] ? UIViewAnimationTransitionFlipFromLeft : UIViewAnimationTransitionFlipFromRight) forView:self.coverListView cache:YES];
if ([self.listButton superview]) {
[self.listButton removeFromSuperview];
[self.coverListView addSubview:self.coverButton];
} else {
[self.coverButton removeFromSuperview];
[self.coverListView addSubview:self.listButton];
}
[UIView commitAnimations];
}
// when the playing album cover changes, remember to update the coverButton:
UIImage *artworkImage; // set this to the current playing album image
[self.coverButton setImage:artworkImage forState:UIControlStateNormal];
// don't forget to call the animateCoverListButtonFlip in the button click handler (shown above as showHideQueue) that shows and hides the cover/queue(list of album tracks0 - something like this:
- (void)showHideQueue
{
[self animateCoverListButtonFlip];
/* replace the code below that is commented out here with your own code that transitions between your cover view and your list view of album tracks, this code shows my transition and references views that are not part of this example/answer, but you don't need those - you'll have your own cover view (musicPlayerView) and list view (musicQueueView) to flip between.
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.75];
[UIView setAnimationTransition:([musicQueueView superview] ? UIViewAnimationTransitionFlipFromLeft : UIViewAnimationTransitionFlipFromRight) forView:self.contentView cache:YES];
if ([musicQueueView superview]) { // if music queue is displayed
[musicQueueView removeFromSuperview];
[self.contentView addSubview:musicPlayerView];
} else {
[musicPlayerView removeFromSuperview];
[self.contentView addSubview:musicQueueView];
[[musicQueueView queueTableView] reloadData];
}
[UIView commitAnimations];*/
}