[英]Aspect fit programmatically in iOS?
I want to insert one view into another with aspect fit option. 我想使用宽高比适合选项将一个视图插入另一个视图。 But I can't just set
contentMode
for some reasons. 但我不能仅仅因为某些原因设置
contentMode
。
Could you provide a solution via resizing of the inner CGRect
according to the outer CGRect
? 您
CGRect
根据外部CGRect
通过调整内部CGRect
大小来提供解决方案?
And yes, there are a lot of similar questions but no one provides such solution. 是的,有很多类似的问题,但没有人提供这样的解决方案。
It will return the CGRect
of a given innerRect
, after scaling it to fit within a given outerRect
, while maintaining aspect ratio. 它将返回
CGRect
给定的innerRect
,缩放以适合一个给定的内后outerRect
,同时保持高宽比。 The innerRect
will be centered within the outerRect
. innerRect
将在outerRect
。
static inline CGRect aspectFitRect(CGRect outerRect, CGRect innerRect) {
// the width and height ratios of the rects
CGFloat wRatio = outerRect.size.width/innerRect.size.width;
CGFloat hRatio = outerRect.size.height/innerRect.size.height;
// calculate scaling ratio based on the smallest ratio.
CGFloat ratio = (wRatio < hRatio)? wRatio:hRatio;
// The x-offset of the inner rect as it gets centered
CGFloat xOffset = (outerRect.size.width-(innerRect.size.width*ratio))*0.5;
// The y-offset of the inner rect as it gets centered
CGFloat yOffset = (outerRect.size.height-(innerRect.size.height*ratio))*0.5;
// aspect fitted origin and size
CGPoint innerRectOrigin = {xOffset+outerRect.origin.x, yOffset+outerRect.origin.y};
CGSize innerRectSize = {innerRect.size.width*ratio, innerRect.size.height*ratio};
return (CGRect){innerRectOrigin, innerRectSize};
}
You can then use this like so: 然后您可以像这样使用它:
// outer rect
CGRect outerRect = CGRectMake(0, 100, self.view.bounds.size.width, 500);
// outer rect's view
UIView* v = [[UIView alloc] initWithFrame:outerRect];
v.backgroundColor = [UIColor greenColor];
[self.view addSubview:v];
// inner rect
CGRect innerRect = CGRectMake(0, 0, self.view.bounds.size.width*2, 500);
CGRect scaledInnerRect = aspectFitRect(v.bounds, innerRect);
// inner rect's view
UIView* v1 = [[UIView alloc] initWithFrame:scaledInnerRect];
v1.backgroundColor = [UIColor redColor];
[v addSubview:v1];
In this case, the innerRect
is too wide for the outerRect
, so it will be scaled according to it's width. 在这种情况下,
innerRect
对于outerRect
来说太宽,所以它将根据它的宽度进行缩放。
Here, the red area is the innerRect
and the green area is the outerRect
. 这里,红色区域是
innerRect
,绿色区域是outerRect
。 They both originally had the same height, but after being scaled down (as it was 2x as wide), the innerRect
now has half the height of the outerRect
. 它们最初都具有相同的高度,但在按比例缩小后(宽度为2
outerRect
), innerRect
现在具有outerRect
高度的outerRect
。
Here the innerRect
is added as a subview to the outerRect
. 这里
innerRect
作为子视图添加到outerRect
。 If you want to add them to the same superview, you can pass the outerRect
's frame
into the function, rather than the bounds
. 如果要将它们添加到同一个
outerRect
,可以将outerRect
的frame
传递给函数,而不是bounds
。
Here are CGSize and CGRect extensions for fitting a size within another size and fitting a rect within another rect respectively: 下面是CGSize和CGRect扩展,用于在另一个大小内拟合大小并分别在另一个矩形中拟合rect:
extension CGSize
{
func sizeThatFitsSize(_ aSize: CGSize) -> CGSize
{
let width = min(self.width * aSize.height / self.height, aSize.width)
return CGSize(width: width, height: self.height * width / self.width)
}
}
extension CGRect
{
func rectThatFitsRect(_ aRect:CGRect) -> CGRect
{
let sizeThatFits = self.size.sizeThatFitsSize(aRect.size)
let xPos = (aRect.size.width - sizeThatFits.width) / 2
let yPos = (aRect.size.height - sizeThatFits.height) / 2
let ret = CGRect(x: xPos, y: yPos, width: sizeThatFits.width, height: sizeThatFits.height)
return ret
}
}
// Your First View
UIView *firstView = self;
// Your second View
UIView *secondView = [[UIView alloc] initWithFrame:CGRectZero]; change
newSubview.translatesAutoresizingMaskIntoConstraints = NO;
[containerView addSubview:newSubview];
// Top Constraint
[firstView addConstraint:[NSLayoutConstraint constraintWithItem:secondView
attribute:NSLayoutAttributeTop
relatedBy:NSLayoutRelationEqual
toItem:firstView
attribute:NSLayoutAttributeTop
multiplier:1.0
constant:0.0]];
// Leading Constraint
[firstView addConstraint:[NSLayoutConstraint constraintWithItem:secondView
attribute:NSLayoutAttributeLeading
relatedBy:NSLayoutRelationEqual
toItem:firstView
attribute:NSLayoutAttributeLeading
multiplier:1.0
constant:0.0]];
// Bottom Constraint
[firstView addConstraint:[NSLayoutConstraint constraintWithItem:secondView
attribute:NSLayoutAttributeBottom
relatedBy:NSLayoutRelationEqual
toItem:firstView
attribute:NSLayoutAttributeBottom
multiplier:1.0
constant:0.0]];
// Trailing Constraint
[firstView addConstraint:[NSLayoutConstraint constraintWithItem:secondView
attribute:NSLayoutAttributeTrailing
relatedBy:NSLayoutRelationEqual
toItem:firstView
attribute:NSLayoutAttributeTrailing
multiplier:1.0
constant:0.0]];
}
I think This helps You. 我想这有助于你。
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