这是在ios开发中常见的功能。即，touch移动事件，是移动到当前视图的子视图中，还是移动到当前视图以外了。

办法是，继承UIView，覆盖touchesMoved方法：

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

    UITouch *touch=[touches anyObject]; 

    if (![self pointInside:[touch locationInView:self] withEvent:nil]) { 

        NSLog(@"touches moved outside the view"); 

    }else { 

        UIView *hitView=[self hitTest:[[touches anyObject] locationInView:self] withEvent:nil]; 

        if (hitView==self) { 

            NSLog(@"touches moved in the view"); 

        }else{ 

            NSLog(@"touches moved in the subview"); 

        } 

    } 

}