禁用在iPad上使用手写笔滚动

Question

我试图在UIScrollView上取消滚动，如果它来自手写笔（Apple Pencil）。

任何建议？

Answer 1

您可以在UIGestureRecognizer上设置allowedTouchTypes属性。

例如：

scrollView.panGestureRecognizer.allowedTouchTypes = [UITouchType.direct.rawValue as NSNumber]

Answer 2

你可以通过UITouch的类型找出触控是否来自手写笔。

if (touch.type == UITouchTypeStylus) {
     //its touch from Stylus.
}

现在，对于scrollview，您可以创建UIScrollview的子类并实现TouchBegan方法

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event 
{
    UITouch *touch = [[event allTouches] anyObject];
    if (touch.type == UITouchTypeStylus) {
       self.scrollEnabled = NO;
     }
    else
    {
       self.scrollEnabled = YES;
    }
    [super touchesBegan:touches withEvent:event];

}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
    UITouch *touch = [[event allTouches] anyObject];
    if (touch.type == UITouchTypeStylus) {
      self.scrollEnabled = NO;
    }
    else
   {
      self.scrollEnabled = YES;
   }
   [super touchesMoved:touches withEvent:event];

}

//编辑 OR

子类UIApplication：

 @interface MyUIApplication : UIApplication
  - (void)sendEvent:(UIEvent *)event {

        [super sendEvent:event];
        NSSet *allTouches = [event allTouches];
        if ([allTouches count] > 0) {

             / 
             UITouchPhase phase = ((UITouch *)[allTouches anyObject]).phase;
             if (phase == UITouchPhaseBegan){

                   UITouch *touch = [allTouches  anyObject];


                if (touch.type == UITouchTypeStylus) {


                   [[NSNotificationCenter defaultCenter] postNotificationName:@"DisableScroll"  object:self];
                 }
               else
                {

                   [[NSNotificationCenter defaultCenter] postNotificationName:@"EnableScroll"  object:self];
                 }
             }

        }
    }
    @end




int main(int argc, char *argv[])
    {
          @autoreleasepool {
                return UIApplicationMain(argc, argv, NSStringFromClass([MyUIApplication class]), NSStringFromClass([AppDelegate class]));
          }
    }

在包含滚动视图的类中添加这些通知的观察者，并相应地启用/禁用滚动。