Question

我对转换不了解的东西。我想放大一下UIView的右上角（主视图）。我使用CGAffineTransformScale并尝试设置center / anchorPoint以及CGAffineTransformMakeTranslation无效。

我无法弄清楚如何正确设置翻译，以便放大这一点。

CGAffineTransform tr = CGAffineTransformScale(self.view.transform, 2, 2);

[UIView animateWithDuration:2.5 delay:0 options:0 animations:^{
            self.view.transform = tr;
            self.view.center = CGPointMake(480,0);

} completion:^(BOOL finished) {}];

Answer 1

您正在将视图的中心设置在右上角。这意味着你正在放大到中心左下角的某个地方。

试试这个

CGAffineTransform tr = CGAffineTransformScale(self.view.transform, 2, 2);
CGFloat h = self.view.frame.size.height;
[UIView animateWithDuration:2.5 delay:0 options:0 animations:^{
    self.view.transform = tr;
    self.view.center = CGPointMake(0,h);
} completion:^(BOOL finished) {}];

这会将放大视图的中心设置为左下角，有效放大，右上角固定。

此代码没有硬编码的高度，这更加便携（对于iPhone 5的iPad）。

在设置h属性之前，您需要先保存transform，因为在此之后您不应该依赖frame的值。

修改

要使其适用于任何比例s，请使用：

CGFloat s = 3; CGAffineTransform tr = CGAffineTransformScale(self.view.transform, s, s); CGFloat h = self.view.frame.size.height; CGFloat w = self.view.frame.size.width; [UIView animateWithDuration:2.5 delay:0 options:0 animations:^{ self.view.transform = tr; self.view.center = CGPointMake(w-w*s/2,h*s/2); } completion:^(BOOL finished) {}];

要使其适用于左下角，请使用：

CGFloat s = 3; CGAffineTransform tr = CGAffineTransformScale(self.view.transform, s, s); CGFloat h = self.view.frame.size.height; CGFloat w = self.view.frame.size.width; [UIView animateWithDuration:2.5 delay:0 options:0 animations:^{ self.view.transform = tr; self.view.center = CGPointMake(w*s/2,h-h*s/2); } completion:^(BOOL finished) {}];

要使其适用于右下角，请使用：

CGFloat s = 3; CGAffineTransform tr = CGAffineTransformScale(self.view.transform, s, s); CGFloat h = self.view.frame.size.height; CGFloat w = self.view.frame.size.width; [UIView animateWithDuration:2.5 delay:0 options:0 animations:^{ self.view.transform = tr; self.view.center = CGPointMake(w-w*s/2,h-h*s/2); } completion:^(BOOL finished) {}];

另请参阅：How to scale (zoom) a UIView to a given CGPoint

Answer 2

如果有人仍然感兴趣，这里是Swift 3.0解决方案，我添加了正确淡出的可能性。

（我知道有两个枚举遗失，但代码仍然可读，我想你会得到这个概念）

func animateZoom(direction: ZoomDirection, type: ZoomType, duration: Double = 0.3, scale: CGFloat = 1.4) {
    var cx, cy: CGFloat
    var tr: CGAffineTransform = CGAffineTransform.identity

    if (type == .IN) { tr = self.transform.scaledBy(x: scale, y: scale) }

    let h: CGFloat = self.frame.size.height;
    let w: CGFloat = self.frame.size.width;

    if (type == .IN) {
        switch direction {
        case .LEFT_DOWN:
            cx = w*scale/2
            cy = h-h*scale/2
            break
        case .LEFT_UP:
            cx = w*scale/2
            cy = h*scale/2
            break
        case .RIGHT_UP:
            cx = w-w*scale/2
            cy = h*scale/2
            break
        case .RIGHT_DOWN:
            cx = w-w*scale/2
            cy = h-h*scale/2
            break
        }
    } else {
        cx = w/scale/2
        cy = h/scale/2
    }

    UIView.animate(withDuration: duration, delay: 0, options: [.curveEaseInOut], animations: {
        self.transform = tr
        self.center = CGPoint(x: cx, y: cy)
    }, completion: { finish in })
}

（比例）在某一点放大UIView

2 个答案: