IOS BUG 处理UIControl触摸事件TrackingWithEvent

IOS BUG记录 之 处理UIControl的点击事件。UIControl的触摸事件的方法是beginTrackingWithTouch:withEvent:，continueTrackingWithTouch:withEvent:，endTrackingWithTouch:withEvent:，cancelTrackingWithEvent:

##下面简单的介绍一下

• beginTrackingWithTouch:withEvent：是控件被拖动，让其进入高亮状态；
• endTrackingWithTouch:withEvent：结束触摸，取消高亮，恢复状态。
• continueTrackingWithTouch:withEvent：手指移动过程。
• cancelTrackingWithEvent: 取消触摸，取消高亮，恢复状态。

今天遇到一个问题BUG，当点击时直接移开手指时要求被点击的控件变小后恢复状态；还需要长时间触摸在该控件上，手指不移开的时候，控件一直保持在变小的状态，一段时间移开手指时控件恢复正常的状态，以便响应用户的操作。

使用的控件继承UIControl

##第一种情况：当点击时直接移开手指时要求被点击的控件变小后恢复状态；

点击触发事件问题，UIControlEventTouchUpInside

        [view addTarget:self action:@selector(viewClicked:) forControlEvents:UIControlEventTouchUpInside];

点击事件的方法

        - (void) viewClicked:(id)sender {
    DFBaseView *view = (DFBaseView *)sender;
    view.userInteractionEnabled = NO;
    
    __weak typeof(view) weakView = view;
    
    __weak typeof(self) weakSelf = self;
    [view didSelectedAnimation:^{
        __strong typeof(weakSelf) strongSelf = weakSelf;
        __weak typeof(weakView) strongView = weakView;

        //todo something
        strongView.userInteractionEnabled = YES;
    }];
}

点击的时候的动画处理，先变小后恢复

        - (void)didSelectedAnimation:(void (^) (void))block {
    [UIView animateWithDuration:0.15 animations:^{
        self.layer.transform = CATransform3DMakeScale(kTransformScale, kTransformScale, 1);
    } completion:^(BOOL finished) {
        [UIView animateWithDuration:0.15 animations:^{
            self.layer.transform = CATransform3DMakeScale(1.0, 1.0, 1);
        } completion:^(BOOL finished) {
            self.animationHighlighted = NO;
            block();
        }];
    }];
}

从上面的代码，我们可以看出，是UIControl的点击事件，动画结束后回调block，之后//todo something 如push跳转等操作。

##第二种情况：长时间触摸在该控件上，手指不移开的时候，控件一直保持在变小的状态，一段时间移开手指时控件恢复正常的状态。

这个时候上面的代码就满足不了了，需要实现如下的几个方法

• (BOOL)beginTrackingWithTouch:(UITouch *)touch withEvent:(nullable UIEvent *)event;
• (void)endTrackingWithTouch:(nullable UITouch *)touch withEvent:(nullable UIEvent *)event; // touch is sometimes nil if cancelTracking calls through to this.
• (void)cancelTrackingWithEvent:(nullable UIEvent *)event; // event may be nil if cancelled for non-event reasons, e.g. removed from window

具体实现

- (BOOL)beginTrackingWithTouch:(UITouch *)touch withEvent:(UIEvent *)event {
    [UIView animateWithDuration:0.15 animations:^{
        self.layer.transform = CATransform3DMakeScale(kTransformScale, kTransformScale, 1);
    } completion:^(BOOL finished) {
    }];
    return [super beginTrackingWithTouch:touch withEvent:event];
}

- (BOOL)continueTrackingWithTouch:(UITouch *)touch withEvent:(UIEvent *)event {
    return [super continueTrackingWithTouch:touch withEvent:event];
}

- (void)endTrackingWithTouch:(UITouch *)touch withEvent:(UIEvent *)event {
    [super endTrackingWithTouch:touch withEvent:event];
    [UIView animateWithDuration:0.15 animations:^{
        self.layer.transform = CATransform3DMakeScale(1.0, 1.0, 1);
    } completion:^(BOOL finished) {
    }];
}

- (void)cancelTrackingWithEvent:(UIEvent *)event {
    [super cancelTrackingWithEvent:event];
    [UIView animateWithDuration:0.15 animations:^{
        self.layer.transform = CATransform3DMakeScale(1.0, 1.0, 1);
    } completion:^(BOOL finished) {
    }];
}

本文作为学习记录，以便之后查阅。谢谢。