View的初始化函数

ShopView类

#import "ShopView.h"

@implementation ShopView

- (instancetype)init{
    
    self = [super init];
    
    if (self != nil) {
        
        NSLog(@"%s",__func__);
        
    }
    
    return self;
}

- (instancetype)initWithFrame:(CGRect)frame{
    
    self = [super initWithFrame:frame];
    
    if (self != nil) {
        
        NSLog(@"%s",__func__);
    }
    
    return self;
}

@end

init 方法内部会调用initWithFrame:方法

ShopView *shopView = [[ShopView alloc] init];

打印结果

 viewControll生命周期[946:54524] -[ShopView initWithFrame:]
 viewControll生命周期[946:54524] -[ShopView init]

initWithFrame:方法内部不会调用init 方法

ShopView *shopView = [[ShopView alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];

打印结果

 viewControll生命周期[975:57255] -[ShopView initWithFrame:]