如何在Swift中增加或减小按钮的大小？

Question

我UIButton在我的应用程序中有一个叫做"buttonPlay"的应用程序.我正在使用AutoLayout但按钮没有任何NSLayoutConstraints附加到它.

我想编码动画来增加和减少按钮的高度和宽度.以下是动画代码的外观:

    // "Repeat" because the animation must repeat itself
    UIView.animateWithDuration(1.0, delay: 0.6, options: UIViewAnimationOptions.Repeat, animations: {
        // Animation code goes here
        // nil: the animation is not supposed to end
        }, completion: nil)
}

要获取x位置,y位置,宽度和高度的原始值,我使用以下代码:

var frmPlay : CGRect = self.buttonPlay.frame

// get the current x and y positions
        let originXbutton = frmPlay.origin.x
        let originYbutton = frmPlay.origin.y

// get the current width and height of the button     
        let originWidthbutton = frmPlay.size.width
        let originHeightbutton = frmPlay.size.height

// set the frame (frmPlay) to the button frame
        self.buttonPlay.frame = frmPlay

好的,现在是时候增加或减少动画的宽度和高度了.我将把这段代码放在animation块中:

        self.buttonPlay.frame = CGRectMake(
            originXbutton,
            originYbutton,
            originWidthbutton-100,
            originHeightbutton)

        self.buttonPlay.frame = CGRectMake(
            originXbutton,
            originYbutton,
            originWidthbutton+100,
            originHeightbutton)

动画代码看起来像这样:

    UIView.animateWithDuration(1.0, delay: 0.6, options: UIViewAnimationOptions.Repeat, animations: {

        println("Animation function animateStuff() started!")

        var frmPlay : CGRect = self.buttonPlay.frame

        let originXbutton = frmPlay.origin.x
        let originYbutton = frmPlay.origin.y

        let originWidthbutton = frmPlay.size.width
        let originHeightbutton = frmPlay.size.height

        self.buttonPlay.frame = frmPlay

        self.buttonPlay.frame = CGRectMake(
            originXbutton,
            originYbutton,
            originWidthbutton-100,
            originHeightbutton)

        self.buttonPlay.frame = CGRectMake(
            originXbutton,
            originYbutton,
            originWidthbutton+100,
            originHeightbutton)

        }, completion: nil)

让我们运行应用程序.哦哦!按钮(也称为buttonPlay)不会以任何方式变大或变小.虽然它从右向左移动.但是嘿!我没有触及x和y位置代码.

是什么导致的？

Answer 1

使用UIViewAnimationOptions.Repeat并UIViewAnimationOptions.Autoreverse一起做到这一点.您只需在动画块内设置一个帧更改.您不能对动画块内的同一属性进行多次状态更改.

UIView.animateWithDuration(1.0, delay: 0.6, options:
    UIViewAnimationOptions.Repeat | UIViewAnimationOptions.Autoreverse | UIViewAnimationOptions.AllowUserInteraction, animations: {

    println("Animation function animateStuff() started!")

    var frmPlay : CGRect = self.buttonPlay.frame

    let originXbutton = frmPlay.origin.x
    let originYbutton = frmPlay.origin.y

    let originWidthbutton = frmPlay.size.width
    let originHeightbutton = frmPlay.size.height

    self.buttonPlay.frame = frmPlay

    self.buttonPlay.frame = CGRectMake(
        originXbutton,
        originYbutton,
        originWidthbutton+100,
        originHeightbutton)

    }, completion: { finished in

})

UIViewAnimationOptionRepeat:无限期重复动画.

UIViewAnimationOptionAutoreverse:向后和向前运行动画.必须与UIViewAnimationOptionRepeat选项结合使用.

如果要上下按下按钮,

UIView.animateWithDuration(1.0, delay: 0.6, options:
    UIViewAnimationOptions.Repeat | UIViewAnimationOptions.Autoreverse | UIViewAnimationOptions.AllowUserInteraction, animations: {

        self.buttonPlay.transform = CGAffineTransformMakeScale(1.5, 1.5)
    }, completion: { finished in

})