Question

我是IOS App Development的新手。我有一个2 UIView和1 ScrollView的视图。其中一个UIView是一个页脚，我想以这样的方式设置动画，它会根据某些条件隐藏/显示进出屏幕。但是，当我更改页脚的框架（显示/隐藏页脚）时，没有任何反应。

所以我做了一个页脚的NSLog和self.view.subviews [2]，发现页脚框架已成功更改，但同样的更改未反映在self.view中。

如果我每次调用hideFooter / showFooter时都会 [self.view addSubview：footer] 解决我的问题，但是我的滚动视图（我无法纠正，因此这不是很糟糕）一个选项）。

我在这里遗漏了什么吗？有没有办法修改UIView的框架，以便更改反映在UI中？（我已经阅读了关于修改UIView框架的大部分答案。如果没有将UIView再次添加到self.view，似乎没有。）

请注意，我已经在@implementation中的类中全局声明了footer，并且只在viewDidLoad调用的方法中初始化了一次。

@implementation PlayAudioViewController
UIButton *play;
UIButton *next;
UIButton *previous;
UIView* header;
UIView* footer;

- (void)viewDidLoad
{
    [self addFooter];
}
-(void)addFooter{

    footer = [[UIView alloc]initWithFrame:CGRectMake(0, self.view.frame.size.height * 1, self.view.frame.size.width, self.view.frame.size.height * 0.1)];
    UIImageView *headerImage = [[UIImageView alloc]initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height * 0.1)];
    headerImage.image = [UIImage imageNamed:@"Wooden-Background.jpg"];

    [footer addSubview:headerImage];
    footer.backgroundColor = [UIColor redColor];

    queue = [[NSMutableArray alloc] init];
    play = [[UIButton alloc]initWithFrame:CGRectMake(footer.frame.size.width * 0.475, footer.frame.size.height * 0.10, footer.frame.size.height * 0.80, footer.frame.size.height * 0.80)];
    [play setBackgroundImage:[UIImage imageNamed:@"play_1.png"] forState:UIControlStateNormal];
    [play setBackgroundImage:[UIImage imageNamed:@"stop.png"] forState:UIControlStateSelected];
    [play addTarget:self action:@selector(universalplay:) forControlEvents: UIControlEventTouchUpInside];
    play.enabled = YES;
    [footer addSubview:play];

    next = [[UIButton alloc]initWithFrame:CGRectMake(footer.frame.size.width * 0.675, footer.frame.size.height * 0.20, footer.frame.size.height * 0.60, footer.frame.size.height * 0.60)];
    [next setBackgroundImage:[UIImage imageNamed:@"next.png"] forState:UIControlStateNormal];
    [next addTarget:self action:@selector(nextplay:) forControlEvents: UIControlEventTouchUpInside];
    next.enabled=NO;
    [footer addSubview:next];

    previous = [[UIButton alloc]initWithFrame:CGRectMake(footer.frame.size.width * 0.29, footer.frame.size.height * 0.20, footer.frame.size.height * 0.60, footer.frame.size.height * 0.60)];
    [previous setBackgroundImage:[UIImage imageNamed:@"previous.png"] forState:UIControlStateNormal];
    [previous addTarget:self action:@selector(previousplay:) forControlEvents: UIControlEventTouchUpInside];
    previous.enabled=NO;
    [footer addSubview:previous];
    NSLog(@"%@", footer.subviews[1]);
    [self.view addSubview:footer];

    [self hideFooter];
}

-(void)showFooter{
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:2];
    footer.frame = CGRectMake(0, self.view.frame.size.height * 0.9, self.view.frame.size.width, self.view.frame.size.height * 0.1);
    //[self.view addSubview:footer];
    [UIView commitAnimations];
    NSLog(@"%@", self.view.subviews[0]);
    NSLog(@"%@", self.view.subviews[1]);
    NSLog(@"%@", ((UIButton *)((UIView *)self.view.subviews[2]).subviews[1]));

}

-(void)hideFooter{
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:2];
    footer.frame = CGRectMake(0, self.view.frame.size.height * 1, self.view.frame.size.width, self.view.frame.size.height * 0.1);
    //[self.view addSubview:footer];
    [UIView commitAnimations];
}

如前所述，如果我取消注释addFooter和showFooter中的注释语句，动画效果很好，但我的scrollView被搞砸了（新添加的子视图停止反映）。

此外，我还面临着播放，暂停和下一个按钮的类似问题。这些按钮将不时启用或禁用。当我更改.enable属性时，更改不再反映在self.view中。

请帮助我理解这种不寻常行为背后的原因。

更改UIView的帧不会更新其父级子视图数组中的帧。因此，立场不会改变

0 个答案: