#import <UIKit/UIKit.h>@interface XMGImageView : UIView/** <#注释#> */@property (nonatomic, strong) UIImage *image;- (instancetype)initWithImage:(UIImage *)image;@end

#import "XMGImageView.h"@implementation XMGImageView- (instancetype)initWithImage:(UIImage *)image {    if (self = [super init]) {        //确定当前ImageView的尺寸大小        self.frame = CGRectMake(0, 0, image.size.width, image.size.height);        _image = image;    }    return self;}-(void)setImage:(UIImage *)image {    _image = image;    //重绘    [self setNeedsDisplay];}- (void)drawRect:(CGRect)rect {    // Drawing code    [self.image drawInRect:rect];    }@end

#import "ViewController.h"#import "XMGImageView.h"@interface ViewController ()/** <#注释#> */@property (nonatomic, weak) UIImageView *imageV;@property (nonatomic, weak)  XMGImageView *xmgImageV;@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];    // Do any additional setup after loading the view, typically from a nib.        //    UIImageView *imageV = [[UIImageView alloc] init];//    imageV.frame  = CGRectMake(0, 0, 200, 200);//    imageV.image = [UIImage imageNamed:@"CTO"];//    self.imageV = imageV;//    [self.view addSubview:imageV];        //initWithImage创建的ImageView的大小跟原始图片一样大//    UIImageView *imageV = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"CTO"]];//    [self.view addSubview:imageV];                XMGImageView *xmgImageV = [[XMGImageView alloc] initWithImage:[UIImage imageNamed:@"CTO"]];    [self.view addSubview:xmgImageV];    ////    XMGImageView *xmgImageV = [[XMGImageView alloc] init];//    xmgImageV.frame  = CGRectMake(0, 0, 200, 200);//    xmgImageV.image = [UIImage imageNamed:@"CTO"];//    self.xmgImageV = xmgImageV;//    [self.view addSubview:xmgImageV];        }-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {        //self.imageV.image = [UIImage imageNamed:@"汽水"];    self.xmgImageV.image = [UIImage imageNamed:@"汽水"];}@end