动画中断时未调用 UIView 动画完成块

Question

我试图在动画结束时调用一个方法，但在某些情况下，例如，当用户离开应用程序时，它的完成块永远不会被调用。 此外，当 VC 与 UIView 动画同时出现其动画时，完成块永远不会被调用。

即使动画以某种方式中断，我应该怎么做才能确保调用回调？ 我应该根本不使用 UIView 动画完成块并使用其他东西吗？请赐教..！

-(void)action {

[UIView animateWithDuration:0.3
                      delay:0.0
                    options:UIViewAnimationOptionCurveEaseOut
                 animations:^{

                     self.doorLeft.frame = CGRectMake(0, 0, self.doorLeft.frame.size.width, self.doorLeft.frame.size.height);
                     self.doorRight.frame = CGRectMake(self.frame.size.width -self.doorRight.frame.size.width, 0, self.doorRight.frame.size.width, self.doorRight.frame.size.height);

                 } completion:^(BOOL finished){
                     if (finished) {
                         switch (self.type) {
                             case 0:
                                 [self.delegate startTOship];
                                 break;
                             case 1:
                                 [self.delegate gameTOship];
                                 break;
                             case 2:
                                 [self.delegate shipTOgame];
                                 break;
                             case 3:
                                 [self.delegate shipTOmap];
                                 break;
                             case 4:
                                 [self.delegate gameTOmap];
                                 break;
                             case 5:
                                 [self.delegate mapTOgame];
                                 break;
                             case 6:
                                 [self.delegate mapTOship];
                                 break;
                         }

                         [UIView animateWithDuration:0.3
                                               delay:0.5
                                             options:UIViewAnimationOptionCurveEaseOut
                                          animations:^{

                                              self.doorLeft.frame = CGRectMake(-self.doorLeft.frame.size.width, 0, self.doorLeft.frame.size.width, self.doorLeft.frame.size.height);
                                              self.doorRight.frame = CGRectMake(self.doorRight.frame.size.width *2, 0, self.doorRight.frame.size.width, self.doorRight.frame.size.height);

                                          } completion:^(BOOL finished){
                                              if (finished) {

                                                  [self actionEnded];
                                              }
                                          }
                          ];
                     }
                 }
 ];}

Answer 1

您可以做的是改用CATransaction。

[CATransaction begin];

[CATransaction setCompletionBlock:^{
    [self actionEnded]
}];

[UIView animateWithDuration:8.3 delay:0.5 options:UIViewAnimationOptionCurveEaseOut animations:^{

    self.doorLeft.frame = CGRectMake(-self.doorLeft.frame.size.width, 0, self.doorLeft.frame.size.width, self.doorLeft.frame.size.height);
    self.doorRight.frame = CGRectMake(self.doorRight.frame.size.width *2, 0, self.doorRight.frame.size.width, self.doorRight.frame.size.height);

} completion:nil];

[CATransaction commit];

如果动画完全中断，则几乎立即调用完成块。当动画不间断地完成时，也会调用该块。

P.S：CATransaction 适用于所有 UIView 动画。只要你在动画发生之前说begin，在动画代码之后说commit。