新建子类继承UITextView，子类需遵循UIGestureRecognizerDelegate协议

@interface SubTextView : UITextView<UIGestureRecognizerDelegate>

@end

@implementation SubTextView

//通过touch事件，判断是否是UITouchTypePencil
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {
    if (touch.type == UITouchTypePencil) {
        self.editable = NO;
        return NO;
    }
    self.editable = YES;
    return YES;
}

//本次touch结束时，重置可编辑状态，
//避免当pencil切换手指点击唤起键盘时，需要连续点两次
- (void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    [super touchesEnded:touches withEvent:event];
    self.editable = YES;
}

@end