具有Voice Over活动的手势识别器

Question

我开发了一个应用程序，允许用户在画布上绘制他的手指签名。 此功能是使用UIPanGestureRecognizer实现的，具有在UIView中绘制线条的特定目标操作，但是当“Voice Over”处于活动状态时，手势识别器操作不再被触发。

手势初始化代码

UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(pan:)];
pan.maximumNumberOfTouches = pan.minimumNumberOfTouches = 1;
[self addGestureRecognizer:pan];

手势动作代码

- (void)pan:(UIPanGestureRecognizer *)pan {
    CGPoint currentPoint = [pan locationInView:self];
    CGPoint midPoint = midpoint(previousPoint, currentPoint);

    if (pan.state == UIGestureRecognizerStateBegan)
    {
        [path moveToPoint:currentPoint];
    }
    else if (pan.state == UIGestureRecognizerStateChanged)
    {
        [path addQuadCurveToPoint:midPoint controlPoint:previousPoint];
    }

    previousPoint = currentPoint;

    [self setNeedsDisplay];
}

有没有办法在视图中使用“Voice Over”激活的手势绘制一条线？

谢谢和问候！

Answer 1

我解决了我的问题设置UIView画布的isAccessibilityElement和accessibilityTraits属性：

canvasView.isAccessibilityElement = YES;
canvasView.accessibilityTraits = UIAccessibilityTraitAllowsDirectInteraction;