ios - 如何等待动画——完成 block

Question

我正在开发一个应用程序，其中两个 View 在屏幕上的某处相遇。当他们相遇时，碰撞检测器会触发这种方法。它应该识别适当的基础，然后将两个 View 都发送给它。它确实做到了，但它会立即发生，而不是在 4 秒内发生。我错过了什么？ RADIUS 在此代码上方定义。它与箭头不是 UIView 有什么关系吗？ spriteView 类是 UIView 的子类。

-(void)sendToBase:(spriteView *)arrow
{
   int teamNumber = arrow.teamNumber;
   // Find the location of the base.
   for (UIView *scaledView in self.view.subviews) {
      if (scaledView.tag == 100) {
         for (UIView *base in scaledView.subviews) {
            if (base.tag >= 1000) {
               if (teamNumber + 1000 == base.tag) {
                  // We found the right base.
                  CGPoint newCenter;
                  newCenter.x = base.center.x + arc4random() % (int) floor(RADIUS) - RADIUS/2.0;
                  newCenter.y = base.center.y + arc4random() % (int) floor(RADIUS) - RADIUS/2.0;
                  [UIView animateWithDuration:4.0 delay:0.0 options:UIViewAnimationCurveLinear animations:^{
                     [arrow setCenter:newCenter];
                  } completion:^(BOOL finished) {
                     // After walking back to base, remove and create new objects
                     [arrow removeFromSuperview];
                     [self addArrow:scaledView toTeam:teamNumber];
                  }];
               }
            }
         }
      }
   }
}

如果类类型不匹配是问题所在，我因此修改了代码，结果相同。

-(void)sendToBase:(spriteView *)arrow
{
   UIView *uiSpriteView = (UIView *)arrow;
   int teamNumber = arrow.teamNumber;
   // Find the location of the base.
   for (UIView *scaledView in self.view.subviews) {
      if (scaledView.tag == 100) {
         for (UIView *base in scaledView.subviews) {
            if (base.tag >= 1000) {
               if (teamNumber + 1000 == base.tag) {
                  // We found the right base.
                  CGPoint newCenter;
                  newCenter.x = base.center.x + arc4random() % (int) floor(RADIUS) - RADIUS/2.0;
                  newCenter.y = base.center.y + arc4random() % (int) floor(RADIUS) - RADIUS/2.0;
                  [UIView animateWithDuration:4.0 delay:0.0 options:UIViewAnimationCurveLinear animations:^{
                     [uiSpriteView setCenter:newCenter];
                  } completion:^(BOOL finished) {
                     // After walking back to base, remove and create new objects
                     [arrow removeFromSuperview];
                     [self addArrow:scaledView toTeam:teamNumber];
                  }];
               }
            }
         }
      }
   }
}

Answer 1

根据文档，您必须使用 beginAnimations:context:和 commitAnimations center 的动画方法属性(property)。