将CGRect置于视图中

Question

我有一个显示在CGRect中的图像.如何在视图中居中矩形？

这是我的代码:

UIImage * image = [UIImage imageNamed:place.image];
CGRect rect = CGRectMake(10.0f, 90.0f, image.size.width, image.size.height);

UIImageView * imageView = [[UIImageView alloc] initWithFrame:rect];
[imageView setImage:image];

我已经尝试过imageView.center但没有效果.

提前致谢.

Answer 1

看着:

https://developer.apple.com/documentation/coregraphics/cggeometry

你可以做:

CGPoint center = CGPointMake(CGRectGetMidX(mainRect), CGRectGetMidY(mainRect));

Answer 2

UIView center是一个属性,而不是一种方法.

您需要计算要放入的实际位置.您可以通过设置视图的框架或设置其中心来完成此操作,这在您的情况下更简单.

你没有说出你在哪个视图中进行imageView子视图.如果你把它放在调用的东西里面superview,你可以这样做:

CGPoint superCenter = CGPointMake(CGRectGetMidX([superview bounds]), CGRectGetMidY([superview bounds]));
[imageView setCenter:superCenter];

Answer 3

根据parentView的rect的大小和原点将imageView放在parentView中.

给定名为parentView的父视图:

float parentRect = parentView.frame;
float imageRect = imageView.frame;

imageRect.origin.x = (int)(parentView.origin.x + (parentRect.size.width - imageRect.size.width) / 2);
imageRect.origin.y = (int)(parentView.origin.y + (parentRect.size.height- imageRect.size.height) / 2);
imageView.frame = imageRect;

将原点投射到int可确保您的居中图像不模糊(尽管它可能偏离子像素数量的中心).

Answer 4

CGRect r = thingToCenter.frame;
r.origin = parentView.bounds.origin;
r.origin.x = parentView.bounds.size.width / 2  - r.size.width / 2;
r.origin.y = parentView.bounds.size.height / 2  - r.size.height / 2 + 12;
thingToCenter.frame = r;

Answer 5

CGRect CGRectIntegralCenteredInRect(CGRect innerRect, CGRect outerRect) {
    CGFloat originX = outerRect.origin.x + ((outerRect.size.width - innerRect.size.width) * 0.5f);
    CGFloat originY = outerRect.origin.y + ((outerRect.size.height - innerRect.size.height) * 0.5f);
    return CGRectIntegral(CGRectMake(originX, originY, innerRect.size.width, innerRect.size.height));
}