4

我想检测从屏幕右下角开始到中间的两指对角线滑动。我尝试添加 UISwipeGestureRecognizer ，其方向设置为“UISwipeGestureRecognizerDirectionUp | UISwipeGestureRecognizerDirectionLeft”，但由于处理程序被调用，即使我从屏幕中间开始滑动到左上角也没有任何效果。

我需要子类 UIGestureRecognizer 还是可以使用 touchesBegan 和 touchesMoved 处理这个？

4

5 回答 5

1

原因的touches方法可以做每一个Gesture，从ios3.2开始支持Gesture。我可以给你一个简单的代码，你可以自己修改。

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
    isTwoFingersBegin = NO;
    isTwoFingersEnd = NO;
    UITouch *touch = [touches anyObject];
    UIView *touchView = [touch view];
    if ([touches count] == 2)
    {
        isTwoFingersBegin = YES;
    }

    touchStartPoint = [touch locationInView:self.view];
}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
    isSwip = YES;
}
#define TOUCH_MOVE_EFFECT_DIST 30
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{   
    UITouch *touch = [touches anyObject];
    UIView *touchView = [touch view];
    touchEndPoint = [touch locationInView:self.view];
    if ([touches count] == 2)
    {
        isTwoFingersEnd = YES;
    }
    CGPoint deltaVector = CGPointMake(touchEndPoint.x - touchStartPoint.x, touchEndPoint.y - touchStartPoint.y);

    if (fabsf(deltaVector.x) > TOUCH_MOVE_EFFECT_DIST
                &&fabsf(deltaVector.y) > TOUCH_MOVE_EFFECT_DIST
                && isSwip &&isTwoFingersBegin&&isTwoFingersEnd) {
                theSwipGesture=RightUpGesture;
            }
    else if (fabsf(deltaVector.x) <- TOUCH_MOVE_EFFECT_DIST
                && fabsf(deltaVector.y) <- TOUCH_MOVE_EFFECT_DIST
                && isSwip&&isTwoFingersBegin&&isTwoFingersEnd) {
                theSwipGesture=LeftDownGesture;
            }

    isSwip = NO;
}
于 2012-07-29T07:00:33.457 回答
1

无论如何touchesBegan，您需要将其子类化才能使用。touchesMoved我会按照UISwipeGestureRecognizerDirectionUp | UISwipeGestureRecognizerDirectionLeft你说的做，然后设置两个CGRects，一个用于可接受的起点，一个用于可接受的终点。然后使用该UIGestureRecognizerDelegate方法gestureRecognizer:shouldReceiveTouch:，使用 . 检查触摸点是否在可接受的起始矩形内CGRectContainsPoint()。然后（我认为）在您的UISwipeGestureRecognizer子类中覆盖touchesEnded:withEvent:，并检查最终触摸是否在可接受的矩形中。如果不是，请将状态设置为UIGestureRecognizerStateCancelled（或者您应该取消手势）。还要确保它附加到的视图具有其multipleTouchEnabled属性集。我实际上还没有尝试过，但是应该这样做。祝你好运！

编辑

实际上，如果您不想担心可接受的起点/终点的特定 rect 值，并使其与设备无关，您可以这样做：

//swap in whatever percentage of the screen's width/height you want in place of ".75f"

//set the origin for acceptable start points
CGFloat startRect_x = self.view.frame.size.width * .75f;
CGFloat startRect_y = self.view.frame.size.height * .75f;

//set the size
CGFloat rectWidth = self.view.frame.size.width - startRect_x;
CGFloat rectHeight = self.view.frame.size.height - startRect_y;

//make the acceptable start point rect
CGRect startRect = CGRectMake(startRect_x, startRect_y, rectWidth, rectHeight);

//set the origin for the accepable end points
CGFloat endRect_x = self.view.center.x - rectWidth/2;
CGFloat endRect_y = self.view.center.y - rectHeight/2;

//make the acceptable end point rect
CGRect endRect = CGRectMake(endRect_x, endRect_y, rectWidth, rectHeight);
于 2012-07-29T07:01:42.360 回答
1

你可以使用一个UIPanGestureRecognizer

- (void)viewPanned:(UIPanGestureRecognizer *)panGR
{
    CGPoint translation = [panGR translationInView:self];

    CGFloat threshold = self.bounds.size.width/2;

    // Detect
    Direction direction = DirectionUnknown;

    if (translation.x > threshold) {
        if (translation.y > threshold) {
            direction = DirectionBottomRight;
        } else if (translation.y < -threshold) {
            direction = DirectionTopRight;
        } else {
            direction = DirectionRight;
        }
    } else if (translation.x < -threshold) {
        if (translation.y > threshold) {
            direction = DirectionBottomLeft;
        } else if (translation.y < -threshold) {
            direction = DirectionTopLeft;
        } else {
            direction = DirectionLeft;
        }
    } else {
        if (translation.y > threshold) {
            direction = DirectionBottom;
        } else if (translation.y < -threshold) {
            direction = DirectionTop;
        }
    }
}
于 2014-11-25T15:03:17.213 回答
0

一种可能的解决方案是在 iPhone 屏幕上绘制一组可能开始滑动的坐标，以及另一个可能结束滑动的坐标。然后在touchesBegan:andtouchesMoved:方法中，您可以比较滑动的起点和终点，并确定它是否符合对角线。

于 2012-07-29T06:58:25.410 回答
0

多谢你们！

我最终在 touchesBegan、touchesMoved 和 touchesEnded 中编写了自定义代码，而其他工作就像魅力一样。

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{

    if ([touches count] == 2) {
        CGPoint nowPoint = [[touches anyObject] locationInView:self];
        if( nowPoint.x >= ALLOWED_X)
            swipeUp = YES;
    }

    [super touchesBegan:touches withEvent:event];
}


-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
    [super touchesMoved:touches withEvent:event];

    if ([touches count] == 2 && swipeUp) {

        CGPoint nowPoint = [[touches anyObject] locationInView:self];
        CGPoint prevPoint = [[touches anyObject] previousLocationInView:self];

        if( nowPoint.x <= prevPoint.x && nowPoint.y <= prevPoint.y){
        }
        else {
            swipeUp = NO;
        }
    }
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
    [super touchesEnded:touches withEvent:event];
    CGPoint nowPoint = [[touches anyObject] locationInView:self];

    if ([touches count] == 2 && swipeUp && nowPoint.x <= DELTA_X && nowPoint.y <= DELTA_Y) {
        NSLog(@"Invoke Method");
    }
    swipeUp = NO;
}

- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event {
    [super touchesCancelled:touches withEvent:event];
    swipeUp = NO;
}
于 2012-07-29T07:13:00.327 回答