目前,只有当我从按钮拖出100像素时,才会触发UIControlEventTouchDragExit.我想自定义这种行为并将该范围带到大约25像素,但我对编程相对较新,并且从未需要覆盖/自定义这样的内置方法.
我在这里读了一些其他帖子,我需要继承UIButton(或者甚至是UIControl？),并覆盖 – (BOOL)beginTrackingWithTouch：(UITouch *)触及withEvent：(UIEvent *)事件和相关方法,但我真的不知道从哪里开始这样做.
有谁可以提供一些关于如何实现这一目标的建议？非常感激！ ^ _ ^
解决方法
覆盖continueTrackingWithTouch：withEvent：像这样在默认装订线内发送DragExit / DragOutside事件：
- (BOOL)continueTrackingWithTouch:(UITouch *)touch withEvent:(UIEvent *)event
{
CGFloat boundsExtension = 25.0f;
CGRect outerBounds = CGRectInset(self.bounds,-1 * boundsExtension,-1 * boundsExtension);
BOOL touchOutside = !CGRectContainsPoint(outerBounds,[touch locationInView:self]);
if(touchOutside)
{
BOOL prevIoUsTouchInside = CGRectContainsPoint(outerBounds,[touch prevIoUsLocationInView:self]);
if(prevIoUsTouchInside)
{
NSLog(@"Sending UIControlEventTouchDragExit");
[self sendActionsForControlEvents:UIControlEventTouchDragExit];
}
else
{
NSLog(@"Sending UIControlEventTouchDragOutside");
[self sendActionsForControlEvents:UIControlEventTouchDragOutside];
}
}
return [super continueTrackingWithTouch:touch withEvent:event];
}