在开发的时候，给控件和界面布局的一直使用CGRectMake，关于CGRect其他的方法比较少用，今天认真的去看了一下CGRect的其他方法，才发现还有很多方法对纯代码布局是很有用的。特别是下面这个几个，对于方法的作用，在代码块中又注释。在swift里，这几个方法变成了属性，同学们在调用的时候注意一点。
CGRectGetMinX,CGRectGetMaxX,CGRectGetMinY,CGRectGetMaxY,CGRectGetMidX,CGRectGetMidY
关于OC：
- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor whiteColor];
UIView *view = [[UIView alloc]initWithFrame:CGRectMake(100, 100, 100, 100)];
view.backgroundColor = [UIColor greenColor];
[self.view addSubview:view];
//获取view的最小X值，也就是这个view的X值
CGFloat minX = CGRectGetMinX(view.frame);
NSLog(@"minx is %f",minX);
//获取view的最大的X值，也就是这个view的X值+view的宽
CGFloat maxX = CGRectGetMaxX(view.frame);
NSLog(@"maxX is %f",maxX);
//获取view的最小Y值，也就是这个view的Y值
CGFloat minY = CGRectGetMinY(view.frame);
NSLog(@"minY is %f",minY);
//获取view的最大Y值，也就是这个view的Y值+view的高度
CGFloat maxY = CGRectGetMaxY(view.frame);
NSLog(@"maxY is %f",maxY);
//获取view的中点X
CGFloat midX = CGRectGetMidX(view.frame);
NSLog(@"midX is %f",midX);
//获取view的中点Y
CGFloat midY = CGRectGetMidY(view.frame);
NSLog(@"midY is %f",midY);
//获取view的高
CGFloat getWidth = CGRectGetWidth(view.frame);
NSLog(@"getWidth is %f",getWidth);
//获取view的宽
CGFloat getHeight = CGRectGetHeight(view.frame);
NSLog(@"getHeight is %f",getHeight);
//判断两个view大小是否一样
BOOL flag = CGRectEqualToRect(view.frame, self.view.frame);
NSLog(@"flag is %d",flag);
//
CGRect rect = CGRectStandardize(view.frame);
NSLog(@"rect x = %f, y = %f, width = %f, height = %f",rect.origin.x,rect.origin.y,rect.size.width,rect.size.height);
//判断view的rect是否为空
BOOL flag1 = CGRectIsNull(view.frame);
NSLog(@"flag is %d",flag1);
//断view的rect是否为空
BOOL flag2 = CGRectIsEmpty(view.frame);
NSLog(@"flag2 is %d",flag2);
//基于某个view，传入X和Y，获取一个新的rect。
//官方文档给出的解释是另个view是否相交
CGRect smallRect = CGRectInset(view.frame, -10, 10);
NSLog(@"%f,%f,%f,%f",smallRect.origin.x,smallRect.origin.y,smallRect.size.width,smallRect.size.height);
UIView *view1 = [[UIView alloc]initWithFrame:smallRect];
view1.backgroundColor = [UIColor redColor];
[self.view addSubview:view1];
}
图片是CGRectInset这个方法的效果
Simulator Screen Shot 2016年9月24日 18.30.59.png
关于Swift：
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = UIColor.white
let greenView = UIView(frame: CGRect(x: 100, y: 100, width: 100, height: 100))
greenView.backgroundColor = UIColor.green
view.addSubview(greenView)
let minX: CGFloat = greenView.frame.minX
print("minX is \(minX)")
let maxX: CGFloat = greenView.frame.maxX
print("maxX is \(maxX)")
let minY: CGFloat = greenView.frame.minY
print("minY is \(minY)")
let maxY: CGFloat = greenView.frame.maxY
print("maxY is \(maxY)")
let midX: CGFloat = greenView.frame.midX
print("midX is \(midX)")
let midY: CGFloat = greenView.frame.midY
print("midY is \(midY)")
let width: CGFloat = greenView.frame.width
print("width is \(width)")
let height: CGFloat = greenView.frame.height
print("height is \(height)")
let rect: CGRect = greenView.frame.insetBy(dx: 10, dy: 10)
let redView = UIView(frame: rect)
redView.backgroundColor = UIColor.red
view.addSubview(redView)
}
Simulator Screen Shot 2016年9月24日 18.27.35.png
啊啊啊，感觉自己坑了自己一大波，走了巨大段的弯路，还是怪自己看官方文档看的少啊。
