////  ViewController.m//  05-Autoresizing#import "ViewController.h"@interface ViewController ()/** 蓝色 */@property (nonatomic, strong) UIView *blueView;@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];        UIView *blueView = [[UIView alloc] init];    blueView.backgroundColor = [UIColor blueColor];    blueView.frame = CGRectMake(0, 0, 250, 250);    [self.view addSubview:blueView];    self.blueView = blueView;        UIView *redView = [[UIView alloc] init];    redView.backgroundColor = [UIColor redColor];    redView.frame = CGRectMake(0, 150, 250, 100);    redView.autoresizingMask = UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleTopMargin | UIViewAutoresizingFlexibleWidth;    [blueView addSubview:redView];}- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{    CGFloat w = 200 + arc4random_uniform(100);    CGFloat h = 200 + arc4random_uniform(100);    self.blueView.frame = CGRectMake(0, 0, w, h);}/** UIViewAutoresizingNone                 = 0, UIViewAutoresizingFlexibleLeftMargin   = 1 << 0, 距离父控件左边的间距是伸缩的（不固定的） UIViewAutoresizingFlexibleRightMargin  = 1 << 2, 距离父控件右边的间距是伸缩的（不固定的） UIViewAutoresizingFlexibleTopMargin    = 1 << 3, 距离父控件顶部的间距是伸缩的（不固定的） UIViewAutoresizingFlexibleBottomMargin = 1 << 5, 距离父控件底部的间距是伸缩的（不固定的） UIViewAutoresizingFlexibleWidth        = 1 << 1, 宽度跟随父控件的宽度进行自动伸缩 UIViewAutoresizingFlexibleHeight       = 1 << 4, 高度跟随父控件的高度进行自动伸缩 */@end