21

我正在处理 UIButton 动画，其中：

设置在UIButton屏幕底部中心并缩放到小尺寸

_menuBtn.transform = CGAffineTransformMakeScale(0.1f, 0.1f);

当应用程序启动时，它应该随着缩放或增长到其原始大小而移动到屏幕的左下方。

- (void)viewDidLoad
{
    [super viewDidLoad];

    _menuBtn.frame = CGRectMake(160, 513, 30, 30); 
    _menuBtn.superview.frame = CGRectMake(160, 513, 30, 30);

    _menuBtn.transform = CGAffineTransformMakeScale(0.1f, 0.1f);
    NSLog(@"_menuBtn: %@ ; _menuBtn.superview: %@", _menuBtn, _menuBtn.superview);
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDelegate:self];
    [UIView setAnimationDuration:5];
    [UIView setAnimationCurve:UIViewAnimationCurveEaseOut];
    CGAffineTransform scaleTrans  = CGAffineTransformMakeScale(1.0f, 1.0f);
    CGAffineTransform lefttorightTrans  = CGAffineTransformMakeTranslation(-200.0f,0.0f);
    _menuBtn.transform = CGAffineTransformConcat(scaleTrans, lefttorightTrans);
    [UIView commitAnimations];

}

问题

当动画开始时，按钮从屏幕的右下角开始移动，而不是在它所在和应该在的底部中心。有什么帮助吗？

日志结果

NSLog(@"%@", _myBtn);

2013-08-14 09:22:38.913 GJCoolNavi[339:c07] <UIButton: 0x813ea30; frame = (0 0; 0 0); opaque = NO; autoresize = TM+BM; layer = <CALayer: 0x813eaf0>>

那是在做动画之前......动画之后的结果是：

2013-08-14 09:30:25.719 GJCoolNavi[612:c07] <UIButton: 0x71206d0; frame = (160 294; 0 0); opaque = NO; autoresize = TM+BM; animations = { transform=<CABasicAnimation: 0x7536a80>; position=<CABasicAnimation: 0x7537dd0>; }; layer = <CALayer: 0x7120790>>
4

4 回答 4

28

你为什么不这样做...

_menuBtn.transform = CGAffineTransformMakeScale(0.1, 0.1);

[UIView animateWithDuration:5.0
options:UIViewAnimationOptionCurveEaseOut
animations:^(){
    _menuBtn.transform = CGAffineTransformMakeScale(1.0, 1.0);
    _menuBtn.center = self.view.center;
}
completion:nil];

我会避免使用变换移动东西。改为更换框架。

编辑

- (void)viewDidLoad
{
    [super viewDidLoad];
}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];

    // for convenience I'm pulling these values out in to variables.
    float buttonWidth = _menuBtn.frame.size.width;
    float buttonHeight = _menuBtn.frame.size.height;
    float viewWidth = self.view.frame.size.width;
    float viewHeight = self.view.frame.size.height;

    // set the button frame to be the bottom center
    // note you shouldn't have to do this as Interface Builder should already place it there.
    // place the button in the horizontal center and 20 points from the bottom of the view.
    _menuBtn.frame = CGRectMake((viewWidth - buttonWidth) * 0.5, viewHeight - buttonHeight - 20, buttonWidth, buttonHeight);

    // scale the button down before the animation...
    _menuBtn.transform = CGAffineTransformMakeScale(0.1, 0.1);

    // now animate the view...
    [UIView animateWithDuration:5.0
                          delay:0.0
                        options:UIViewAnimationOptionCurveEaseOut
                     animations:^{
                         _menuBtn.transform = CGAffineTransformIdentity;
                         _menuBtn.frame = CGRectMake(viewWidth - buttonWidth - 20, viewHeight - buttonHeight - 20, buttonWidth, buttonHeight);
                     }
                     completion:nil];
}

试试这个，让我知道会发生什么。

于 2013-08-13T10:28:30.373 回答
7

这解决了类似的问题。

应用 (UIButton).imageView 动画。

[UIView beginAnimations:nil context:nil];
[UIView setAnimationDelegate:self];
[UIView setAnimationDuration:5];
[UIView setAnimationCurve:UIViewAnimationCurveEaseOut];
CGAffineTransform scaleTrans  = CGAffineTransformMakeScale(1.0f, 1.0f);
CGAffineTransform lefttorightTrans  = CGAffineTransformMakeTranslation(-200.0f,0.0f);
_menuBtn.imageView.transform = CGAffineTransformConcat(scaleTrans, lefttorightTrans);
[UIView commitAnimations];
于 2014-03-19T02:19:51.187 回答
2

这种现象表明您的按钮的原始框架是错误的，可能是因为它的自动调整大小。在开始动画之前尝试将其框架设置为底部中心。

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    _menuBtn.superview.frame = CGRectMake(0, 513, 320, 30); // This is a quick and dirty solution to make sure your button's superview is in the right place. You probably don't want to do this and are more likely to review your view hierarchy.
    _menuBtn.frame = CGRectMake(145, 0, 30, 30); // Set the frame to the bottom center, please ensure that _menuBtn's transform hasn't been changed before this step
    _menuBtn.transform = CGAffineTransformMakeScale(0.1f, 0.1f);
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDelegate:self];
    [UIView setAnimationDuration:5];
    [UIView setAnimationCurve:UIViewAnimationCurveEaseOut];
    CGAffineTransform scaleTrans  = CGAffineTransformMakeScale(1.0f, 1.0f);
    CGAffineTransform lefttorightTrans  = CGAffineTransformMakeTranslation(-200.0f,0.0f);
    _menuBtn.transform = CGAffineTransformConcat(scaleTrans, lefttorightTrans);
    [UIView commitAnimations];
}
于 2013-08-14T03:25:14.923 回答
0

我已经使用了您的代码，并且它完美地从底部中心移动到左下角。可能是您的超级视图不正确。请检查。

于 2013-08-14T08:44:53.547 回答