iOS开发之Quartz2D 六 绘制UIImageView

#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