UIBarButton项的可访问性标识符不起作用

Question

我以编程方式创建UIBarButtonItem并设置其可访问性标识符和标签。这是我正在使用的代码。

_rightBarButton = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 40.0f, 40.0f)];
    buttonImage = [[UIImage imageNamed:@"bt_send_.png"] resizableImageWithCapInsets:UIEdgeInsetsMake(0, 0.0f, 0, 0.0f)];
    [_rightBarButton setBackgroundImage:buttonImage forState:UIControlStateNormal];
    [_rightBarButton addTarget:self action:@selector(sendQuickNote:) forControlEvents:UIControlEventTouchUpInside];
    //Accessibility Identifier for Send Button
    _rightBarButton.isAccessibilityElement = YES;
    _rightBarButton.accessibilityIdentifier = @"Send Note";
    _rightBarButton.accessibilityLabel = @"Send Note";
    [_rightBarButton setTitle:@"Send Note" forState:UIControlStateNormal];

    self.sendButtonItem = [[UIBarButtonItem alloc] initWithCustomView:_rightBarButton];
    self.sendButtonItem.enabled = NO;

    //Accessibility Identifier for Send Button
    self.sendButtonItem.isAccessibilityElement = YES;
    self.sendButtonItem.accessibilityIdentifier = @"Send Note";
    self.sendButtonItem.accessibilityLabel = @"Send Note";
    [self.sendButtonItem setTitle:@"Send Note"];


    [self.navigationItem addRightBarButtonItem:self.sendButtonItem];

但Appium检查器中没有可访问性标识符。我在这做错了什么？

感谢。