objective-c - 如何让 UILabel 文本在几秒后消失？

Question

我的匹配纸牌游戏有一个 UILabe，上面写着“Good match!”例如，如果你有匹配项，我想在用消息通知用户后让它消失。

那是什么方法呢？我可以让它消失吗..？谢谢。

这是我的 updateUI 方法:

    -(void) updateUI {

    for (UIButton *cardButton in self.cardButtons) {
        Card *card = [self.game cardAtIndex:[self.cardButtons indexOfObject:cardButton]];
        [cardButton setTitle:card.contents forState:UIControlStateSelected];
        [cardButton setTitle:card.contents forState:UIControlStateSelected|UIControlStateDisabled];
        cardButton.selected = card.isFaceUp;
        cardButton.enabled = !card.unplayble;
        if (card.unplayble) {
            cardButton.alpha = 0.1;
        }
        self.scoreCounter.text = [NSString stringWithFormat:@"Score: %d", self.game.score];


        if (self.game.notification) {
            [UIView animateWithDuration:2 animations:^{
                self.notificationLabel.text = [NSString stringWithFormat:@"%@", self.game.notification];
                self.notificationLabel.alpha = 0;
            }];
        }

    }
}

Answer 1

这将在两秒内淡出标签。将 animateWithDuration: 更改为您想要的长度

if (self.game.notification == nil) {
[UIView animateWithDuration:2 animations:^{
self.notificationLabel.alpha = 0;
}];
}

如果你想改变文本，试试这个(我现在不能测试，所以它可能不起作用)

[UIView animateWithDuration:2 animations:^{
self.notificationLabel.text = @"text you want to change it to";
}];

然后，当你想再次使用标签时，你必须将 self.notificationLabel.alpha 设置回 1。所以尝试

if (self.game.notification) {
self.notificationLabel.alpha = 1;
[UIView animateWithDuration:2 animations:^{
self.notificationLabel.text = [NSString stringWithFormat:@"%@", self.game.notification];
self.notificationLabel.alpha = 0;
}];
}