Ios 在“TouchesBegind:withEvent”中添加子视图在绘制之前有延迟

这是容器视图：

@implementation

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    [self.tapView removeFromSuperview];
    self.tapView = nil;
    self.tapView = [[UIView alloc] initWithFrame:CGRectInset(self.bounds, 10.0f, 10.0f)];
    self.tapView.backgroundColor = [UIColor redColor];
    [self addSubview:self.tapView]; // Takes too much time before view shows up on screen
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
    [self.tapView removeFromSuperview];
    self.tapView = nil;
}

@end

我想了解为什么在将tapView添加为子视图和在屏幕上绘制之间会有延迟。虽然只有几毫秒，但很明显

我希望实现的最佳性能示例是在本机键盘上轻敲。点击一个键会显示一个新的视图，或者是它？马上。

想好了！ 容器视图位于启用了“延迟内容触摸”的滚动视图中