UIBarButtonItem不在Play和Pause之间切换

Question

我编写了以下代码来切换标识符播放和暂停之间的按钮。按钮在播放时必须是播放类型，并在播放时暂停。

- (IBAction)playSound:(id)sender {

    if (isPaused) {
        playOrPauseButton = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemPause target:self action:@selector(pausePlaying)];
//        playOrPauseButton.style = UIBarButtonSystemItemPause;
//        [playOrPauseButton setStyle:UIBarButtonSystemItemPause];
        isPaused = NO;
        NSLog(@"Playing");
    }

    else {

        playOrPauseButton = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemPlay target:self action:@selector(resumePlaying)];
//        playOrPauseButton.style = UIBarButtonSystemItemPlay;
//        [playOrPauseButton setStyle:UIBarButtonSystemItemPlay];
        isPaused = YES;
        NSLog(@"Paused");

    }

}

评论的陈述是我从网上得到的不同选项，我逐一尝试。这三个选项都没有在播放和暂停状态之间切换。我在故事板中将按钮标识符设置为播放。无论我做什么，按钮仍然是播放按钮。如何将按钮切换为播放/暂停类型？

Answer 1

只需为您的方法编写代码： -

-(IBAction)pausePlaying
{
    NSLog(@"push tap");
    if(playing == YES)
    {
        playOrPauseButton = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemPause target:self action:@selector(resumePlaying)];
        self.navigationItem.rightBarButtonItem = playOrPauseButton;
        playing= NO;
    }
}

-(IBAction)resumePlaying
{
    if(playing == NO)
    {  
        playOrPauseButton = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemPlay target:self action:@selector(pausePlaying)];
        self.navigationItem.rightBarButtonItem = playOrPauseButton;
        playing= YES;  
    }

    NSLog(@"resume tap");    
}


- (void)viewDidLoad
{
    playing=YES; 
    playOrPauseButton = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemPlay target:self action:@selector(pausePlaying)];
    self.navigationItem.rightBarButtonItem = playOrPauseButton;
    [super ViewDidLoad:animated];
}

工作屏幕截图： -

Answer 2

设置工具栏项目就像这样

UIBarButtonItem *spaceItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil];
[self.navigationController.toolbar setBarStyle:UIBarStyleBlackOpaque];
UIBarButtonItem *customItem = [[UIBarButtonItem alloc] initWithTitle:@"toolbar title" style:UIBarButtonItemStylePlain    target:self     action:@selector(onToolbarTapped:)];
NSArray *toolbarItems = [NSArray arrayWithObjects:spaceItem, customItem, spaceItem, nil];

[self setToolbarItems:toolbarItems animated:NO];

制作一组条形按钮，将其设置为工具栏项

因此，在您的情况下，不仅不修改也在工具栏中设置它以使其正常工作