Question

我有一个应用程序，你必须用触摸移动不同的字母（以UILabels的形式）。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：

移动不平滑，标签在我的手指移动图像后停止移动（显然是因为if (CGRectContainsPoint(a.frame, touchPoint))
此外，一旦我在移动另一个标签时绕过标签，我的手指开始移动标签我绕过

我怎么能这样做，我知道现在正在做的事情有更好的方法......

Answer 1

尝试将其全部放在一个链式动画中touchesMoved是旧学校。在每个标签上添加手势识别器。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;
}

Answer 2

我会尝试创建一个新的UILabel类，它将实现touchesBegan，touchesMoved和touchesEnded。将相关代码放在每个方法中。为此类创建一个方法，为成员分配字母的值。在ViewController中实例化此类的每个新对象，并在此处设置其字母以及其他必要的详细信息，例如label.center。我希望这会有所帮助。

我的代码示例（使用UIImage，你需要找到一种用UILabel初始化类的方法，但标准方法是这样做的）：

@implementation myClass

- (id)initWithImage:(UIImage *)image
{
    if (self = [super initWithImage:image])
        self.userInteractionEnabled = YES;

    return self;
}


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

    UITouch * touch = [touches anyObject];
    pos = [touch locationInView: self];


    self.center = pos;


        NSLog(@"Touches Began Called.");

}


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

    activePoint = [[touches anyObject] locationInView:self];    

    int dx = self.center.x + (activePoint.x - pos.x); 
    int dy = self.center.y + (activePoint.y - pos.y);

    CGPoint newPoint = CGPointMake(dx,dy);
    self.center = newPoint;

        NSLog(@"Touches Moved Called.");


}

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



    NSLog(@"Touches Ended Called.");

}

用触摸移动多个对象

2 个答案: