ios - UIView 动画无法正常工作

Question

我在使用 UIView subview 动画时遇到了一些问题。我想要做的是，当您按下主视图时， subview 将从顶部向下滑动，然后在下一次点击时它会向上滑动并被删除。但在当前状态下，它只执行第一次点击命令，在第二次点击时显示 nslog，但 View 和动画的移除不起作用。

这是事件处理函数中的代码:

- (void)tapGestureHandler: (UITapGestureRecognizer *)recognizer
{
NSLog(@"tap");

CGRect frame = CGRectMake(0.0f, -41.0f, self.view.frame.size.width, 41.0f);
UIView *topBar = [[UIView alloc] initWithFrame:frame];
UIColor *background = [[UIColor alloc] initWithPatternImage:[UIImage imageNamed:@"topbar.png"]];
topBar.backgroundColor = background;

if (topBarState == 0) {
     [self.view addSubview:topBar];
    [UIView animateWithDuration:0.5 animations:^{topBar.frame = CGRectMake(0.0f, 0.0f, self.view.frame.size.width, 41.0f);}];
    topBarState = 1;
} else if (topBarState == 1){
    [UIView animateWithDuration:0.5 animations:^{topBar.frame = CGRectMake(0.0f, -41.0f, self.view.frame.size.width, 41.0f);} completion:^(BOOL finished){[topBar removeFromSuperview];}];

    NSLog(@"removed");
    topBarState = 0;
}

}

如何使 subview 动画化并正确删除？

最好的问候

自由 Restful

Answer 1

您总是将 topBar 框架设置为 y = -41，因此对于 topBarState = 1，动画适用于 y=-41 到 y=-41 并且似乎不起作用

CGRect frame = CGRectMake(0.0f, -41.0f, self.view.frame.size.width, 41.0f);
UIView *topBar = [[UIView alloc] initWithFrame:frame];

每次创建 View topBar 时。
在 .h 中声明 topBar 并在 viewDidLoad 中分配初始化。

- (void)viewDidLoad {
    CGRect frame = CGRectMake(0.0f, -41.0f, self.view.frame.size.width, 41.0f);
    topBar = [[UIView alloc] initWithFrame:frame];
    UIColor *background = [[UIColor alloc] initWithPatternImage:[UIImage imageNamed:@"topbar.png"]];
    topBar.backgroundColor = background;
        [self.view addSubview:topBar];
    topBarState = 0;
}

- (void)tapGestureHandler: (UITapGestureRecognizer *)recognizer
{
    if (topBarState == 0) {
            [UIView animateWithDuration:0.5 animations:^{topBar.frame = CGRectMake(0.0f, 0.0f, self.view.frame.size.width, 41.0f);}];
            topBarState = 1;
    } else if (topBarState == 1){
        [UIView animateWithDuration:0.5 animations:^{topBar.frame = CGRectMake(0.0f, -41.0f, self.view.frame.size.width, 41.0f);} completion:^(BOOL finished){[topBar removeFromSuperview];}];
        topBarState = 0;
    }
}