原因是当录音的时候，状态栏高度由20变成了40，导致controller整体下移了20

小知识，controller的self.view 即controller显示的大小，通过改变self.view大小 就能控制controller的大小

- (void)viewWillLayoutSubviews{
    [super viewWillLayoutSubviews];
    CGRect frame = self.view.frame;
    frame.size.height -= 20;
    //    frame.origin.y += 20;
    self.view.frame = frame;
    self.view.clipsToBounds = YES;
}

1. 监听状态栏变化的通知

[[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(changeFrame) name:UIApplicationWillChangeStatusBarFrameNotification object:nil];

2. 当状态栏改变时更新controller的self.view大小

    self.oldHeight = [UIScreen mainScreen].bounds.size.height;
- (void)changeFrame{
    CGRect frame = self.view.frame;
    self.view.clipsToBounds = YES;
    CGRect statusBarRect = [[UIApplication sharedApplication] statusBarFrame];
    if (statusBarRect.size.height == 40) {
        frame.size.height = self.oldHeight - 20 - frame.origin.y;
    }
    if (statusBarRect.size.height == 20){
        frame.origin.y = 0;
        frame.size.height = self.oldHeight;
    }
    self.view.frame = frame;
}

项目地址

你可能需要这个