动画状态栏 iOS 7

Question

我正在尝试（正在努力）在 iOS7 中为我的应用程序实现类似 snapchat 的错误消息显示（snapchat 错误消息以某种方式滑过状态栏）。我一辈子都无法让我的动画正常工作。这是我制作动画的方法

- (void)animateHeaderViewWithText:(NSString *)text {

    //add header views
    [self.headerView addSubview:self.headerLabel];
    [self.navigationController.view addSubview:self.headerView];

    //Hide the Status Bar
    statusBarHidden = TRUE;
    [self setNeedsStatusBarAppearanceUpdate];

    self.headerLabel.text = text;

    [UIView animateWithDuration:.5 delay:0.0 options:UIViewAnimationOptionCurveEaseIn animations:^{

        self.headerLabel.frame = CGRectMake(0, 0, 320, 20);
        self.headerView.frame = CGRectMake(0, 0, 320, 20);


    } completion:^(BOOL finished) {


    [UIView animateWithDuration:.5 delay:5.0 options:UIViewAnimationOptionCurveEaseIn animations:^{

        //UnHide the Status Bar
        statusBarHidden = FALSE;
        [self setNeedsStatusBarAppearanceUpdate];

        self.headerLabel.frame = CGRectMake(0, -20, 320, 20);
        self.headerView.frame = CGRectMake(0, -20, 320, 20);



    } completion:^(BOOL finished) {


        [self.headerView removeFromSuperview];
        [self.headerLabel removeFromSuperview];

    }];
}];

}

只有动画的后半部分真正正常工作，消息滑回正常，状态栏出现在其下方。然而，动画的前半部分，当视图向下滑动时，状态栏消失导致我的导航栏向上移动，搞砸了我的动画。如何让我的导航栏保持在最初放置的位置，即使状态栏消失了

Answer 1

此代码在纵向上工作，但需要修改才能在两个方向上正常工作。它使用单独的 UIWindow 作为覆盖，因此无需隐藏或取消隐藏状态栏。

@interface ViewController ()
@property (strong,nonatomic) UIWindow *dropdown;
@property (strong,nonatomic) UILabel *label;
@property (strong,nonatomic) UIWindow *win;
@end

@implementation ViewController

- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];
    self.dropdown = [[UIWindow alloc] initWithFrame:CGRectMake(0, -20, 320, 20)];
    self.dropdown.backgroundColor = [UIColor redColor];
    self.label = [[UILabel alloc] initWithFrame:self.dropdown.bounds];
    self.label.textAlignment = NSTextAlignmentCenter;
    self.label.font = [UIFont systemFontOfSize:12];
    self.label.backgroundColor = [UIColor clearColor];
    [self.dropdown addSubview:self.label];
    self.dropdown.windowLevel = UIWindowLevelStatusBar;
    [self.dropdown makeKeyAndVisible];
    [self.dropdown resignKeyWindow];

}

- (IBAction)dropDown:(UIButton *)sender {
    [self animateHeaderViewWithText:@"This is my test string"];
}


-(void)animateHeaderViewWithText:(NSString *) text {
    self.label.text = text;
    CGRect frame = self.dropdown.frame;
    frame.origin.y = 0;
    [UIView animateWithDuration:.6 delay:0 options:0 animations:^{
        self.dropdown.frame = frame;
    }completion:^(BOOL finished) {
        ;
    }];
}