objective-c - 通过触摸移动多个对象

Question

我有一个应用程序，您必须在其中移动不同的字母(以 UILabels 的形式)触摸。由于有许多不同的 UILabel 对象，我尝试创建此代码，以防止任何标签粘在一起:

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

UITouch *touch = [[event allTouches] anyObject];

CGPoint touchPoint = [touch locationInView: self.view];


bool pickup = YES;


if (pickup) {

    if (CGRectContainsPoint(a.frame, touchPoint)) {

        a.center = touchPoint;

        pickup = NO;
    }
}

if (pickup) {

    if (CGRectContainsPoint(x.frame, touchPoint)) {

        x.center = touchPoint;
        pickup = NO;

    }

}

if (pickup) {

    if (CGRectContainsPoint(x2.frame, touchPoint)) {

        x2.center = touchPoint;
        pickup = NO;

    }

}
if (pickup) {

    if (CGRectContainsPoint(eq.frame, touchPoint)) {

        eq.center = touchPoint;
        pickup = NO;

    }

}        

if (pickup) {

    if (CGRectContainsPoint(b.frame, touchPoint)) {

        b.center = touchPoint;
        pickup = NO;

    }

}


}

但是这里有一些问题:

1. 移动不流畅，一旦我的手指移动图像标签就停止移动(显然是因为 if (CGRectContainsPoint(a.frame, touchPoint))


2. 而且一旦我在移动另一个标签时绕过一个标签，我的手指就会开始移动我绕过的标签

我该怎么做，我知道有比我现在正在做的更好的方法...

Answer 1

尝试将其全部放在一个链式动画中 touchesMoved 是老派。在每个标签上添加一个手势识别器。然后在那个选择器中尝试这个 -

- (void)labelTouchSelector:(UIGestureRecognizer *)gesture
{
    CGPoint touchPoint = [gesture locationInView: self.view];

    [UIView animateWithDuration:1.0 
                          delay:0 
                        options:UIViewAnimationOptionCurveLinear | UIViewAnimationOptionAllowUserInteraction
                     animations:^(void) 
     {
         if(CGRectContainsPoint(a.frame, touchPoint))
         {
              a.center = touchPoint;
              pickup = NO;
         }
     } 
     completion:^(BOOL finished) 
     {
         if(finished)
         {
             //do some cleanup here
             pickup = NO;
         }
     }];
    return;
}