console報(bào)錯(cuò)信息

couldn't find a common superview for <UIScrollView: 0x7fb8a401ac00; frame = (0 0; 0 0); clipsToBounds = YES; gestureRecognizers = <NSArray: 0x7fb8a3c17990>; layer = <CALayer: 0x7fb8a3c235a0>; contentOffset: {0, 0}; contentSize: {0, 0}> and <UIView: 0x7fb8a3c1c970; frame = (0 0; 375 667); autoresize = W+H; layer = <CALayer: 0x7fb8a3c15ff0>>

原因

不能為scrollView找到父視圖，原因?yàn)楫?dāng)scrollView被創(chuàng)建后，使用masonry對(duì)scrollView進(jìn)行設(shè)置約束(constrains)時(shí)會(huì)找視圖進(jìn)行參考，我們這里是以其父視圖view進(jìn)行參考，但此時(shí)scrollView并未添加到view中，所以運(yùn)行會(huì)直接崩掉，解決辦法為使添加到父控件的代碼優(yōu)先執(zhí)行即可。

原代碼:

scrollView.backgroundColor = [UIColor brownColor];    
[scrollView mas_makeConstraints:^(MASConstraintMaker *make) 
{
       make.size.mas_equalTo(self.view);    
}];
[self.view addSubview:scrollView];```

####改正后:
```UIScrollView *scrollView = UIScrollView.new;
[self.view addSubview:scrollView];  //從尾部提高到此處
scrollView.backgroundColor = [UIColor brownColor];    
[scrollView mas_makeConstraints:^(MASConstraintMaker *make) 
{
      make.size.mas_equalTo(self.view);
}];```