Question

如果这是一个显而易见的问题，我很抱歉，但我是初学iOS开发新手，我一直在寻找一个小时的答案而没有任何成功。

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

我可以使用以下代码显示对话框并连接到键盘。问题是，没有办法解雇对话框。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会显示。

- (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，不确定是否覆盖此类按钮

Answer 1

这对我有用（对于iPhone版）：

- (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];

}

Answer 2

曾经有一个错误，视图控制器覆盖了导航栏的任何左键。如果我没记错的话，这在iOS 10中得到了修复。

确保故事板上有导航栏。这段代码依赖于self是一个带有UINavigationController的UIViewController的事实。

以下是一些适合我的代码：

- (IBAction)configureCentral:(UIButton*)sender {
    centralViewController = [[CABTMIDICentralViewController alloc] init];
    [self.navigationController pushViewController: centralViewController animated:YES];
}

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

- (UIViewController *)presentationController:(UIPresentationController *)controller viewControllerForAdaptivePresentationStyle:(UIModalPresentationStyle)style {
    UIBarButtonItem *doneButton = [[UIBarButtonItem alloc] initWithTitle:@"Done" style:UIBarButtonItemStyleDone target:self action:@selector(handleDone:)];
    UINavigationController *nav = (UINavigationController *)controller.presentedViewController;
    nav.topViewController.navigationItem.leftBarButtonItem = doneButton;

    return controller.presentedViewController;
}

- (UIModalPresentationStyle)adaptivePresentationStyleForPresentationController:(UIPresentationController *)controller {
     return UIModalPresentationOverFullScreen;
}

您可以使用相同的技巧来显示localPeripheralViewController。

无法将“完成”按钮添加到CABTMIDICentralViewController

2 个答案: