淺談OC物件初始化的三種姿勢

一、普通程式猿
普通程式設計師使用最常見路人姿勢等場。普普通通，純屬陸仁輩。

陸仁賈寫法：

// view 1
 
UIView *v1 = [UIView alloc] initWithFrame:CGRectMake(0, 0, 200, 100)];
v1.backgroundColor = [UIColor whiteColor];
 
// view 2
 
UIView *v2 = [UIView alloc] initWithFrame:CGRectMake(0, 120, 200, 100)];
v2.backgroundColor = [UIColor whiteColor];
 
// add to view
[self.view addSubview:v1];
[self.view addSubview:v2];

 

 

擼人已寫法：擼人已明顯比陸仁賈聰明多了。使用大括號隔離，view1與view2相互獨立，建立程式碼變數不會相互汙染。

// view 1
{
    UIView *v1 = nil;
    UIView *v = [UIView alloc] initWithFrame:CGRectMake(0, 0, 200, 100)];
    v.backgroundColor = [UIColor whiteColor];

    v1 = v;

    [self.view addSubview:v1];
}

// view 2
{
    UIView *v2 = nil;
    UIView *v = [UIView alloc] initWithFrame:CGRectMake(0, 120, 200, 100)];
    v.backgroundColor = [UIColor whiteColor];

    v2 = v;

    [self.view addSubview:v2];
}

 

路人餅寫法

// view 1
UIView *v1 = nil;
{
    UIView *v = [UIView alloc] initWithFrame:CGRectMake(0, 0, 200, 100)];
    v.backgroundColor = [UIColor whiteColor];
    v1 = v;
}

// view 2
UIView *v2 = nil;
{
    UIView *v = [UIView alloc] initWithFrame:CGRectMake(0, 120, 200, 100)];
    v.backgroundColor = [UIColor whiteColor];
    v2 = v;
}

[self.view addSubview:v1];
[self.view addSubview:v2];

 

二、文藝程式猿
文藝程式猿，使用教科書姿勢登場。使用builder模式。使用block隔離初始化程式碼。

首先給NSObject增加擴充套件介面

// 擴充套件NSObject，增加Builder介面

@interface NSObject (Builder)
+ (id)z0_builder:(void(^)(id that))block;
- (id)z0_builder:(void(^)(id that))block;
@end

// 實現
@implementation NSObject (Builder)

+ (id)z0_builder:(void(^)(id))block {
    id instance = [[self alloc] init];
    block(instance);
    return instance;
}

- (id)z0_builder:(void(^)(id))block {
    block(self);
    return self;
}

@end

 

使用。程式碼簡潔工整。處處都是文藝範。

- (void) foo {
// 使用
// view 1
UIView *v1 = [UIView z0_builder:^(UIView *that) {
    that.frame = CGRectMake(0, 0, 320, 200);
    that.background = [UIColor whiteColor];
}];

// view 2
UIView *v2 = [[UIView alloc] init];
[v2 z0_builder:^(UIView *that) {
    that.frame = CGRectMake(0, 0, 320, 200);
    that.background = [UIColor whiteColor];
}];

// 新增到父檢視
[self.view addSubview:v1];
[self.view addSubview:v2];
}

 

三、二逼程式猿
最後入場的是二逼程式猿。

！#！@#@%&……&%&#￥%！@#￥！@#￥!!!!! 這個是什麼卵？
其實....我也不知道！>_<# 自行領悟。
黑科技?????呵呵~~ 我就是程式碼少，你吹啊~~

- (void) foo {
// view 1
  UIView *v1 = ({
      UIView *v = [UIView alloc] init];
      v.frame = CGRectMake(0, 0, 320, 200);
      v.background = [UIColor whiteColor];
      v;
  });

  // view2
  UIView *v2 = ({
      UIView *v = [UIView alloc] init];
      v.frame = CGRectMake(0, 120, 320, 200);
      v.background = [UIColor blueColor];
      v;
  });

  [self.view addSubview:v1];
  [self.view addSubview:v2];
}