为什么两个init函数都被调用

问题描述

如果我有一个像这样设置的类来自定义UIView。

@interface myView：UIView

   - （id）init { 
 self = [super init]; 
 if（self）{
 [self foo]; 
} 
 return self; 
} 
 
  - （id）initWithFrame：（CGRect）frame 
 {
 self = [super initWithFrame：frame]; 
 if（self）{
 //初始化代码
 [self foo]; 
} 
 return self; 
} 
 
 
  - （void）foo {
 //在此处构建UIView 
} 
  pre> 
 
 
如果我使用
 $ f 
 $ b 
  * aView = [[myView alloc] init]]; 
  
或
  myView * aView = [[myView alloc] initWithFram：aFrame]; 
  
 
 
解决方案
  UIView init  call  UIView initWithFrame：。因为你覆盖了两个，调用 init 方法会导致调用 initWithFrame：方法：
 
 
 
换句话说：你的 init 调用 UIView init 。  UIView init 呼叫 initWithFrame：。因为你重载 initWithFrame：，你的 initWithFrame：被调用，依次调用 UIView initWithFrame： 。
 
 
 
解决方案，因为 initWithFrame：从 init 方法中删除对 foo 的调用。
 
If I have a class that is setup like this to customize a UIView. 
@interface myView : UIView
- (id)init {
    self = [super init];
    if(self){
        [self foo];
    }
    return self;
}

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
        [self foo];
    }
    return self;
}


-(void) foo{
   //Build UIView here 
}
How come foo is called twice whether I use 
myView *aView = [[myView alloc]init]]; 
or 
myView *aView = [[myView alloc]initWithFram:aFrame]; 
 解决方案 
UIView init calls UIView initWithFrame:. Since you override both, calling your init method results in your initWithFrame: method being called:
In other words: your init calls UIView init. UIView init calls initWithFrame:. Since you override initWithFrame:, your initWithFrame: is called which in turn calls UIView initWithFrame:.
The solution, since your initWithFrame: will always be called, is to remove the call to foo from your init method.
                        
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