如果这是一个明显的问题，我很抱歉，但我是原生 iOS 开发的新手，我已经搜索了几个小时的答案但没有成功。

我正在开发一个需要连接到蓝牙 MIDI 键盘的应用程序。我在 Apple 的网站上找到了以下文档，其中描述了如何从应用程序管理蓝牙设备 https://developer.apple.com/library/content/qa/qa1831/_index.html

我能够使用以下代码显示对话框并连接到键盘。问题是，没有办法关闭对话框。对于我在代码中看到的内容，添加了“完成”按钮，但在运行应用程序时它不显示。

- (void)doneAction:(id)sender
{
    [self dismissViewControllerAnimated:YES completion:nil];
}

- (IBAction)configureCentral:(id)sender
{
    CABTMIDICentralViewController *viewController = [CABTMIDICentralViewController new];

    UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:viewController];

    // this will present a view controller as a popover in iPad and modal VC on iPhone
    viewController.navigationItem.rightBarButtonItem =
        [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone
                                                      target:self
                                                      action:@selector(doneAction:)];

    navController.modalPresentationStyle = UIModalPresentationPopover;

    UIPopoverPresentationController *popC = navController.popoverPresentationController;
    popC.permittedArrowDirections = UIPopoverArrowDirectionAny;
    popC.sourceRect = [sender frame];

    UIButton *button = (UIButton *)sender;
    popC.sourceView = button.superview;

    [self presentViewController:navController animated:YES completion:nil];
}

CABTMIDICentralViewController 本身作为导航栏的一些控件，具体取决于当前状态，不确定它是否覆盖了此类按钮

最佳答案

这对我有用(对于 iPhone 版本):

- (void)doneAction:(id)sender {
  [self dismissViewControllerAnimated:NO completion:nil];
}

- (IBAction)configureCentral:(id)sender {

  CABTMIDICentralViewController *viewControllerBT = [CABTMIDICentralViewController new];

  UINavigationController *navControllerBT = [[UINavigationController alloc] initWithRootViewController:viewControllerBT];

  UIButton * btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
  btn.frame = CGRectMake(screenSize.width-60, 40, 60, 40);
  btn.titleLabel.font = [UIFont boldSystemFontOfSize:17.0];
  [btn setTitle:@"Done" forState:UIControlStateNormal];
  [btn addTarget:self action: @selector(doneAction:) forControlEvents: UIControlEventTouchDown];
  [navControllerBT.view addSubview:btn];

  [self presentViewController:navControllerBT animated:NO completion:nil];

}

- (IBAction)configureLocalPeripheral:(UIButton *)sender {

  CABTMIDILocalPeripheralViewController *viewControllerBTA = [[CABTMIDILocalPeripheralViewController alloc] init];

  UINavigationController *navControllerBTA = [[UINavigationController alloc] initWithRootViewController:viewControllerBTA];

  UIButton * btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
  btn.frame = CGRectMake(screenSize.width-60, 40, 60, 40);
  btn.titleLabel.font = [UIFont boldSystemFontOfSize:17.0];
  [btn setTitle:@"Done" forState:UIControlStateNormal];
  [btn addTarget:self action: @selector(doneAction:) forControlEvents: UIControlEventTouchDown];
  [navControllerBTA.view addSubview:btn];

  [self presentViewController:navControllerBTA animated:NO completion:nil];

}

关于ios - 无法将 "Done"按钮添加到 CABTMIDICentralViewController，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/39547797/