带持续时间的iOS zoomToRect

可能重复：

是否有任何方法可以复制[UIScrollView zoomToRect:zoomRect animated:YES]的行为，从而使动画持续给定的时间？

如何使用：

[UIView beginAnimations:@"" context:nil];
[UIView setAnimationDuration:2.0]; //Or any other duration

[theScroll setContentOffset:offsetPoint]; //offsetPoint is a CGPoint that defines the point you want your scroller to show

[UIView commitAnimations];

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缺点是您需要计算精确的CGPoint以获得您想要达到的正确偏移量。

我使用一些CA3DTransforms实现了zoomToRect。如果有人感兴趣，我会把代码贴在这里

我必须保留对scrollView原始框架的引用，这样才能工作

rect.origin.x = ((int)rect.origin.x) % (int)self.initialFrame.size.width;    
float scale = MIN(self.initialFrame.size.width / rect.size.width,self.initialFrame.size.height / rect.size.height);

CGSize scaledFrameSize = CGSizeMake(self.initialFrame.size.width / scale, self.initialFrame.size.height / scale);

CGPoint middleOfFrame = CGPointMake(self.initialFrame.size.width / 2 ,self.initialFrame.size.height / 2);
CGPoint transformPoint = CGPointMake(rect.origin.x + scaledFrameSize.width / 2,rect.origin.y + scaledFrameSize.height/2);
CGPoint offsetToCenter = CGPointMake((scaledFrameSize.width - rect.size.width) / 2 * scale,( scaledFrameSize.height - rect.size.height)/ 2 * scale);

[UIView animateWithDuration:1 animations:^ {
    self.layer.transform = CATransform3DConcat(CATransform3DConcat(CATransform3DConcat(CATransform3DMakeTranslation(middleOfFrame.x,middleOfFrame.y, 0),
                                               CATransform3DMakeTranslation(-transformPoint.x, -transformPoint.y,0)),
                                               CATransform3DMakeScale(scale, scale, 1)),
                                               CATransform3DMakeTranslation(offsetToCenter.x, offsetToCenter.y, 0));
}];

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您可以将其放入

UIScrollView

子类中：

- (void)zoomToRect:(CGRect)rect animated:(BOOL)animated
{
    [UIView animateWithDuration:(animated?0.3f:0.0f)
                          delay:0
                        options:UIViewAnimationOptionBeginFromCurrentState
                     animations:^{
                         [super zoomToRect:rect animated:NO];
                     } 
                     completion:nil];
}

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我尝试了这一方法，您还必须设置缩放级别，并且生成的动画与zoomToRect不同。