为什么CALayer的移动速度比UIView慢？

发布于 2024-12-09 11:35:47 字数 886 浏览 2 评论 0原文

我有一个 UIView 子类，当用户触摸事件时，它会使用以下重写方法来移动它们：

// In a custom UIView...

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
    CGPoint point = [[touches anyObject] locationInView:self];
    UIView *eventView = [self.ringOfEvents hitTest:point withEvent:event];
    for (EventView *e in self.events) {
        if (e == eventView) {
            event.position = point;
        }
    }
}

为什么当我将 EventView 设为 CALayer 而不是 UIView 时，移动速度会减慢到蠕动？我也可以发布该代码，但它非常相似，我认为没有必要。

我认为抽象到较低的级别会加快事件处理速度，但我一定错过了一些东西。

顺便说一句，如果 *eventView 是 UIView 或 CALayer 的子类，则 position 属性如下：

- (void)setPosition:(CGPoint)pos {
    self.layer.position = pos;
}

- (CGPoint)position {
    return self.layer.position;
}

不知道为什么使用 UIView 而不是 CALayer 时延迟会大幅减少。

原文

I have a UIView subclass that moved around 'event's when the user touches them, using the following overridden method:

// In a custom UIView...

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
    CGPoint point = [[touches anyObject] locationInView:self];
    UIView *eventView = [self.ringOfEvents hitTest:point withEvent:event];
    for (EventView *e in self.events) {
        if (e == eventView) {
            event.position = point;
        }
    }
}

Why is it that when I make EventView a CALayer instead of UIView, the movement slows down to a creep? I can post that code too, but it is so similar that I don't think it is necessary.

I would think that abstracting to a lower level would speed up event handling, but I must be missing something.

By the way, either if *eventView is a subclass of UIView or CALayer, the position property is as follows:

- (void)setPosition:(CGPoint)pos {
    self.layer.position = pos;
}

- (CGPoint)position {
    return self.layer.position;
}

Not sure why I get a huge decrease in latency when using UIView as apposed to CALayer..

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要走干脆点 2024-12-16 11:35:47

默认情况下，大多数 CALayer 属性都会随动画一起更改，因此延迟的减少可能就是由此引起的。

您可能希望在更改图层位置时禁用动画。例如，此处和此处

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心意如水 2024-12-16 11:35:47

这是由于隐式动画造成的。

我已经实现了一个类别方法，它删除了给定键的隐式动画，并且可以像这样

[view.layer setNullAsActionForKeys:@[@"bounds", @"position"]];

使用

@implementation CALayer (Extensions)

- (void)setNullAsActionForKeys:(NSArray *)keys
{
    NSMutableDictionary *dict = [self.actions mutableCopy];

    if(dict == nil)
    {
        dict = [NSMutableDictionary dictionaryWithCapacity:[keys count]];
    }

    for(NSString *key in keys)
    {
        [dict setObject:[NSNull null] forKey:key];
    }

    self.actions = dict;
}

@end

This is due to implicit animations.

I've implemented a category method which removes implicit animation for givven keys and can be used like this

[view.layer setNullAsActionForKeys:@[@"bounds", @"position"]];

Implementation

@implementation CALayer (Extensions)

- (void)setNullAsActionForKeys:(NSArray *)keys
{
    NSMutableDictionary *dict = [self.actions mutableCopy];

    if(dict == nil)
    {
        dict = [NSMutableDictionary dictionaryWithCapacity:[keys count]];
    }

    for(NSString *key in keys)
    {
        [dict setObject:[NSNull null] forKey:key];
    }

    self.actions = dict;
}

@end

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~没有更多了~