ios - 收到错误 "Unknown receiver coachMarksView; Did you mean WSCoachMarksView error?"

Question

我目前正在实现 WSCoachMarksView在首次使用该应用程序时向用户介绍功能的框架。然而，我的 viewDidAppear 中的代码给出了以下错误: Unknown receiver 'coachMarksView';您是说“WSCoachMarksView”吗？

我不确定为什么会这样，因为我已经在 viewDidLoad 中实例化了 coachMarksView，所以它应该可以识别它。我错过了什么吗？

- (void)viewDidLoad
{
    [super viewDidLoad];

    // Setup coach marks
    NSArray *coachMarks = @[
                            @{
                                @"rect": [NSValue valueWithCGRect:(CGRect){{50,168},{220,45}}],
                                @"caption": @"Just browsing? We'll only notify you periodically of new matches. Need it soon? We'll notify you more frequently, and match you with items that are closer to you."
                                },
                            ];

    WSCoachMarksView *coachMarksView = [[WSCoachMarksView alloc] initWithFrame:self.navigationController.view.bounds coachMarks:coachMarks];
    [self.navigationController.view addSubview:coachMarksView];
    coachMarksView.animationDuration = 0.5f;
    coachMarksView.enableContinueLabel = YES;
    [coachMarksView start];
}

- (void)viewDidAppear:(BOOL)animated
{

    // Show coach marks
    BOOL coachMarksShown = [[NSUserDefaults standardUserDefaults] boolForKey:@"WSCoachMarksShown"];
    if (coachMarksShown == NO) {
        // Don't show again
        [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"WSCoachMarksShown"];
        [[NSUserDefaults standardUserDefaults] synchronize];

        // Show coach marks
        [coachMarksView start];

        // Or show coach marks after a second delay
        // [coachMarksView performSelector:@selector(start) withObject:nil afterDelay:1.0f];
    }   
}

Answer 1

您需要将 coachMarksView 设为一个属性，以便您可以访问同一实例。 coachMarksView 在 vi​​ewWillAppear: 中未定义，因为该范围不知道 viewDidLoad 中的范围。

要为 coachMarksView 创建属性，您需要在 viewController 中执行以下操作:

@interface UIViewController ()
@property (nonatomic, strong) WKCoachMarksView *coachMarksView;
@end

然后在viewDidLoad

- (void)viewDidLoad
{
  self.coachMarksView = [[WSCoachMarksView alloc] initWithFrame:self.navigationController.bounds]];
}

现在只需使用 self.coachMarksView 即可访问该实例。

- (void)viewDidAppear:(BOOL)animated
{
  [super viewDidAppear:animated];
  [self.coachMarksView start];
}

这里是关于 Objective-C 中的 getter、setter 和属性的更多信息 http://rypress.com/tutorials/objective-c/properties.html