我正在尝试在UIButton上实现拖放功能,它可以正常工作,但是我无法确定如何在用户松开按钮并完成拖动时进行通知。以下代码适用于拖动,但我需要在用户完成拖动并松开按钮时得到通知。
- (void)viewDidLoad
{
[gesturesBrowserButton addTarget:self action:@selector(wasDragged:withEvent:)
forControlEvents:UIControlEventTouchDragInside];
[gesturesBrowserButton addTarget:self action:@selector(finishedDragging:withEvent:)
forControlEvents:UIControlEventTouchDragExit];
}
- (void)wasDragged:(UIButton *)button withEvent:(UIEvent *)event
{
// get the touch
UITouch *touch = [[event touchesForView:button] anyObject];
// get delta
CGPoint previousLocation = [touch previousLocationInView:button];
CGPoint location = [touch locationInView:button];
CGFloat delta_x = location.x - previousLocation.x;
CGFloat delta_y = location.y - previousLocation.y;
// move button
button.center = CGPointMake(button.center.x + delta_x,
button.center.y + delta_y);
NSLog(@"was dragged");
}
- (void)finishedDragging:(UIButton *)button withEvent:(UIEvent *)event
{
//doesn't get called
NSLog(@"finished dragging");
}
UIControlEventTouchDragExit
不会触发吗?我猜你不想要这种情况。 - Rob Napier