带有延迟和持续时间 Ios 的动画标签

Posted 2023-03-12

【中文标题】带有延迟和持续时间 Ios 的动画标签

【英文标题】：Animating Labels with delay and duration Ios

【发布时间】：2016-10-03 06:33:13

【问题描述】：

所以我试图为标签设置动画，该标签将以文本开头，然后在一定时间后它会消失，新文本出现在屏幕上，在一定时间后会消失，然后出现新文本。我希望这递归地发生。我需要继续动画 15 秒，接下来的 15 秒会发生同样的事情。

- (void)viewDidLoad 
    [super viewDidLoad];

    [self MyLabelAnimation];



- (void)MyLabelAnimation 
    self.myLabel.text = @"Text 1";
    [UIView animateWithDuration:0.3 animations:^
        self.myLabel.alpha = 1.0;
     completion:^(BOOL finished) 

        [UIView animateWithDuration:0.3 delay:2.7 options:UIViewAnimationOptionCurveEaseInOut animations:^
            self.myLabel.alpha = 0.0;
         completion:^(BOOL finished) 

            self.myLabel.text = @"Text 2";
            [UIView animateWithDuration:0.3 animations:^
                self.myLabel.alpha = 1.0;
             completion:^(BOOL finished) 
                [UIView animateWithDuration:0.3 delay:2.7 options:UIViewAnimationOptionCurveEaseInOut animations:^
                    self.myLabel.alpha = 0.0;
                 completion:^(BOOL finished) 

                    self.myLabel.text = @"Text 3";
                    [UIView animateWithDuration:0.3 animations:^
                        self.myLabel.alpha = 1.0;
                     completion:^(BOOL finished) 

                        [UIView animateWithDuration:0.3 delay:2.7 options:UIViewAnimationOptionCurveEaseInOut animations:^
                            self.myLabel.alpha = 0.0;
                         completion:^(BOOL finished) 

                            self.myLabel.text = @"Text 4";
                            [UIView animateWithDuration:0.3 animations:^
                                self.myLabel.alpha = 1.0;
                             completion:^(BOOL finished) 
                                [UIView animateWithDuration:0.0 delay:4.8 options:UIViewAnimationOptionCurveEaseInOut animations:^
                                    self.myLabel.alpha = 0.0;
                                 completion:^(BOOL finished) 

                                    [self MyLabelAnimation];
                                ];
                            ];
                        ];
                    ];
                ];
            ];
        ];
    ];

所以我在这里从 viewdidload 调用 mylabel 动画，然后在第 4 个动画的完成块末尾调用该方法。

这里一切都按预期工作，但最后一个动画到第一个动画过渡不平滑，因为其他过渡。是不是因为我错过了什么。我真的无法弄清楚为什么会这样。

其次，Is 是获得这样的动画的正确方法。或者有更好的方法吗？

【问题讨论】：

我也有同样的问题。

你们有谁知道如何在后台暂停动画并在前台再次恢复

我在这里得到了答案link

【参考方案1】：

您可能会发现这样的事情更容易管理：

- (void)viewDidLoad 
    [super viewDidLoad];

    self.counter = 0;
    self.animations = @[
                        @@"Text":@"Hello", @"Duration":@(2.7),
                        @@"Text":@"Text 1", @"Duration":@(2.7),
                        @@"Text":@"Text 2", @"Duration":@(2.7),
                        @@"Text":@"Text 3", @"Duration":@(2.7),
                        @@"Text":@"Text 4", @"Duration":@(4.8),
                        ];

    [self animate:0];



- (void)animate:(int)counter 
    self.counter = counter % self.animations.count;

    NSDictionary *item = self.animations[self.counter];

    self.myLabel.alpha = 0;
    self.myLabel.text = item[@"Text"];

    [UIView animateWithDuration:0.3
                     animations:^
                         self.myLabel.alpha = 1.0;
                      completion:^(BOOL finished) 
                         [UIView animateWithDuration:0.3
                                               delay:[item[@"Duration"] floatValue]
                                             options:UIViewAnimationOptionCurveEaseInOut
                                          animations:^
                                              self.myLabel.alpha = 0.0;
                                           completion:^(BOOL finished) 
                                              [self animate:++self.counter];
                                          ];
                     ];

【讨论】：

你知道当应用程序进入后台时如何暂停动画吗？

将全局BOOL 添加到名为shouldStopAnimation 的类中。检查animate 函数开头的值。如果已设置，则立即返回。为 ApplicationWillEnterBackground 通知添加一个观察者，并在收到时将 bool 值设置为YES。您还可以通过将动画设置为 no NO 并重新调用 animate:self.counter 来重新启动动画。

如果答案解决了您的问题，请不要忘记将答案标记为正确。

【参考方案2】：

试试这个代码....

 - (void)viewDidLoad 
    [super viewDidLoad];

     [NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(MyLabelAnimation:) userInfo:nil repeats:NO];


- (void)MyLabelAnimation:(NSTimer*) timer 
    self->mylabel.text = @"Hello";
    [UIView animateWithDuration:0.3 animations:^
        self->mylabel.alpha = 1.0;
     completion:^(BOOL finished) 

        [UIView animateWithDuration:0.3 delay:2.7 options:UIViewAnimationOptionCurveEaseInOut animations:^
            self->mylabel.alpha = 0.0;
         completion:^(BOOL finished) 

            self->mylabel.text = @"Text 2";
            [UIView animateWithDuration:0.3 animations:^
                self->mylabel.alpha = 1.0;
             completion:^(BOOL finished) 
                [UIView animateWithDuration:0.3 delay:2.7 options:UIViewAnimationOptionCurveEaseInOut animations:^
                    self->mylabel.alpha = 0.0;
                 completion:^(BOOL finished) 

                    self->mylabel.text = @"Text 3";
                    [UIView animateWithDuration:0.3 animations:^
                        self->mylabel.alpha = 1.0;
                     completion:^(BOOL finished) 

                        [UIView animateWithDuration:0.3 delay:2.7 options:UIViewAnimationOptionCurveEaseInOut animations:^
                            self->mylabel.alpha = 0.0;
                         completion:^(BOOL finished) 

                            self->mylabel.text = @"Text 4";
                            [UIView animateWithDuration:0.3 animations:^
                                self->mylabel.alpha = 1.0;
                             completion:^(BOOL finished) 
                                [UIView animateWithDuration:0.0 delay:4.8 options:UIViewAnimationOptionCurveEaseInOut animations:^
                                    self->mylabel.alpha = 0.0;
                                 completion:^(BOOL finished) 

                                     [NSTimer scheduledTimerWithTimeInterval:0.0 target:self selector:@selector(MyLabelAnimation:) userInfo:nil repeats:NO];
                                ];
                            ];
                        ];
                    ];
                ];
            ];
        ];
    ];