用两个图片初始化两个CCSprite，一样的大小，重叠在一起，分别叫做 foregroundNode 和 backgroundNode 。

- (void)flipover{    if (isFliping) {        return;    }    [self chooseCard];}-(void) chooseCard{    isFliping = YES;    CCSprite *fore = nil;    CCSprite *back = nil;    if (flipovered) {        fore = self.foregroundNode;        back = self.backgroundNode;    }else{        fore = self.backgroundNode;        back = self.foregroundNode;    }    //始终保证前面的图像是未横向翻转过的，后面的图像是翻转过的    if ([back flipX] == NO) {        [back setFlipX:YES];    }    if ([fore flipX] == YES) {        [fore setFlipX:NO];    }        //执行动画的时间    float orbitTime = 0.3;        //前景图像转动90度不可见    [fore runAction:[CCSequence actions:[CCOrbitCamera actionWithDuration:orbitTime radius: 1 deltaRadius:0 angleZ:0 deltaAngleZ:90 angleX:0 deltaAngleX:0],[CCCallFunc actionWithTarget:self selector:@selector(showCard:)], nil]];        //背景图像同步旋转，当前景图像停止动画时，背景图像继续旋转90度，此时图像左右是翻转的，为了保证看着的图像是正常的，所以在执行动画前要翻转一次    [back runAction:[CCSequence actions:[CCOrbitCamera actionWithDuration:orbitTime*2 radius:1 deltaRadius:0 angleZ:0 deltaAngleZ:180 angleX:0 deltaAngleX:0], [CCCallFunc actionWithTarget:self selector:@selector(flipFinished)], nil]];}// 翻转后，调整前后景图像的层次-(void)showCard:(id)sender{    if (flipovered) {        [self.foregroundNode setZOrder:0];        [self.backgroundNode setZOrder:1];    }else{        [self.foregroundNode setZOrder:1];        [self.backgroundNode setZOrder:0];    }    flipovered = !flipovered;}- (void)flipFinished{    isFliping = NO;}