如何使用 Objective-C 移动多个对象

Question

这是我的代码

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

    UITouch *myTouch = [[event allTouches] anyObject];
    UITouch *myTouch2 = [[event allTouches] anyObject];
    UITouch *myTouch3 = [[event allTouches] anyObject];

    button.center = [myTouch locationInView:self.view];
    button2.center = [myTouch2 locationInView:self.view];
    button3.center = [myTouch3 locationInView:self.view];   
}

问题是，当我尝试移动其中一个按钮时，它们都在同一时间和同一位置移动。我希望能够单独自由地移动按钮。我怎么做？有什么建议吗？

Answer 1

使用以下内容确定它是哪个按钮：

UITouch *touch = [[event touchesForView:self.view] anyObject];

CGPoint location = [touch locationInView:touch.view];

if(CGRectContainsPoint(button.frame, location)) 
{
    button.center = [myTouch locationInView:self.view];

}
else if(CGRectContainsPoint(button2.frame, location)) 
{
    button2.center = [myTouch locationInView:self.view];

}
else if(CGRectContainsPoint(button3.frame, location)) 
{
    button3.center = [myTouch locationInView:self.view];

}

Answer 2

I want to be able to move buttons separately and freely.

那么你不应该同时把它们全部移动到同一个地方:

UITouch *myTouch = [[event allTouches] anyObject];
UITouch *myTouch2 = [[event allTouches] anyObject];
UITouch *myTouch3 = [[event allTouches] anyObject];

看看 myTouch、myTouch2 和 myTouch3 -- 它们可能都指向同一个触摸对象。在这种情况下，您会将所有按钮移动到同一位置。

如果您希望进行多次触摸，则需要查看 [event allTouches] 中的一组触摸，并确保为每个按钮获得不同的对象。例如，您可以选择最靠近每个按钮的触摸对象，确保您不会对两个按钮使用相同的触摸。

如何使用 Objective-C 移动多个对象

How can I move multiple objects with Objective-C

ios

objective-c

cocoa-touch

touch-event