Question

我已经构建了一个小型测试应用程序，可以在UIButton上应用平移手势。我成功应用了平移手势并成功移动了按钮。但问题是我甚至可以在屏幕外移动按钮。如何限制它仅在iPhone屏幕内移动？这是我的代码：

    - (void)viewDidLoad
{
    [super viewDidLoad];

    UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(pan:)];
    [panGesture setMinimumNumberOfTouches:1];
    [_shareButton addGestureRecognizer:panGesture];
}

-(IBAction)pan:(UIPanGestureRecognizer *)recognizer
{
    CGPoint trans =[recognizer translationInView:self.view];
    recognizer.view.center = CGPointMake(recognizer.view.center.x+trans.x, recognizer.view.center.y+trans.y);
    [recognizer setTranslation:CGPointMake(0, 0) inView:self.view];


}

如何限制按钮移出屏幕？我使用的是iOS 7，xcode 5.0。

Answer 1

这对你有用..但我用 Swift ：

写了

func callMe(sender: UIPanGestureRecognizer)
{
    let translation = sender.translationInView(self.view)

    let newX = sender.view!.center.x + translation.x
    let newY = sender.view!.center.y + translation.y
    let senderWidth = sender.view!.bounds.width / 2
    let senderHight = sender.view!.bounds.height / 2

    if newX <= senderWidth
    {
        sender.view!.center = CGPoint(x: senderWidth, y: sender.view!.center.y + translation.y)
    }
    else if newX >= self.view.bounds.maxX - senderWidth
    {
        sender.view!.center = CGPoint(x: self.view.bounds.maxX - senderWidth, y: sender.view!.center.y + translation.y)
    }
    if newY <= senderHight
    {
        sender.view!.center = CGPoint(x: sender.view!.center.x + translation.x, y: senderHight)
    }
    else if newY >= self.view.bounds.maxY - senderHight
    {
        sender.view!.center = CGPoint(x: sender.view!.center.x + translation.x, y: self.view.bounds.maxY - senderHight)
    }
    else
    {
        sender.view!.center = CGPoint(x: sender.view!.center.x + translation.x, y: sender.view!.center.y + translation.y)
    }

    sender.setTranslation(CGPointZero, inView: self.view)
}

我希望它可以帮助那些寻找最简单方法的人。

Answer 2

像这样编辑你的代码：

-(IBAction)pan:(UIPanGestureRecognizer *)recognizer
{
    CGPoint trans =[recognizer translationInView:self.view];
        if (CGRectContainsPoint([self.view frame], trans)) 
        {
            recognizer.view.center = trans;
        }
}

这里你要做的是，你是否是在视图的框架中。如果是。你正在移动拖动按钮的中心..如果这不能解决你的问题，请告诉我。

更新2：

您也可以使用 onDrag事件，而不是实现PanGesture：

- (IBAction)onButtonDrag:(id)sender forEvent:(UIEvent *)event {

    CGPoint point = [[[event allTouches] anyObject] locationInView:sender.view];
    UIControl *control = sender;
    if (CGRectContainsPoint([self.view frame], point)) {
        control.center = point;
        [self.view touchesEnded:[event allTouches] withEvent:event];
    }

}

Answer 3

试试这个：

UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handlePan:)];
[pan setDelegate:self];
[shareButton addGestureRecognizer:pan]; 

-(void)handlePan:(UIGestureRecognizer*)panGes{
    CGPoint point = [panGes locationInView:self.view];
    if (point.x >20 && point.x <280 && point.y<400 && point.y>30) {
        CGRect newframe = CGRectMake(point.x, point.y, shareButton.frame.size.width, shareButton.frame.size.height);
        shareButton.frame = newframe;
    }
}

并替换20,280＆amp; 400,30与您各自的限制。

Answer 4

你的手势框架的绑定限制。它的大小只是window.width和height。

下面是手势教程。我知道它是用于游戏但是在这个教程中找到你的逻辑。

http://www.raywenderlich.com/2343/cocos2d-tutorial-for-ios-how-to-drag-and-drop-sprites

<强> Disabling Pan Gesture if out of bounds detected

- (CGPoint)boundLayerPos:(CGPoint)newPos {
    CGSize winSize = [CCDirector sharedDirector].winSize;
    CGPoint retval = newPos;
    retval.x = MIN(retval.x, 0);
    retval.x = MAX(self.position.x); 
    retval.y = self.position.y;
    return retval;
}

Answer 5

知道了。编码如下：

    -(IBAction)pan:(UIPanGestureRecognizer *)recognizer
{
    CGPoint trans =[recognizer translationInView:self.view];
    CGFloat sumx = _shareButton.frame.origin.x+_shareButton.frame.size.width+5;
        CGFloat sumy = _shareButton.frame.origin.y+_shareButton.frame.size.height+5;

    CGFloat sumxm = _shareButton.frame.origin.x;
    CGFloat sumym = _shareButton.frame.origin.y;

    NSLog(@"position : %f, %f ", _shareButton.frame.origin.x, _shareButton.frame.origin.y);
    NSLog(@"screen : %f, %f ", self.view.frame.size.width ,self.view.frame.size.height);


    if (sumx > self.view.frame.size.width ||  sumy > self.view.frame.size.height )
    {
        CGRect shareButton = _shareButton.frame;
        shareButton.origin.y -= 1;
                shareButton.origin.x -= 1;
        _shareButton.frame = shareButton;

        return;
    }

    else if(sumxm < 0 || sumym < 0) {
        CGRect shareButton = _shareButton.frame;
        if(sumxm < 0)
        {
        shareButton.origin.x =0;
        }
        if(sumym < 0){
        shareButton.origin.y =0;
        }
        _shareButton.frame = shareButton;
        NSLog(@"share button : %f, %f", _shareButton.frame.origin.x, _shareButton.frame.origin.y);
        return;
    }

           recognizer.view.center = CGPointMake(recognizer.view.center.x+trans.x, recognizer.view.center.y+trans.y);

           [recognizer setTranslation:CGPointMake(0, 0) inView:self.view];




}

Answer 6

-(void)dragAction:(UIPanGestureRecognizer *)gesture{
UIView *vw = (UIView *)gesture.view;

CGPoint translation = [gesture translationInView:vw];
 if (CGRectContainsPoint(vw.frame, [gesture locationInView:vw] )) {
     vw.center = CGPointMake(vw.center.x,
                                vw.center.y);
     [gesture setTranslation:CGPointZero inView:vw];
 }
 else{
     vw.center = CGPointMake(vw.center.x,
                                vw.center.y + translation.y);
     [gesture setTranslation:CGPointZero inView:vw];
 }

UIButton PanGesture不在屏幕上

6 个答案: