Question

我想在视频中添加带动画的不同图像。我有这个用户AVMutableAudioCompostion。我在玩两张图片的过程中取得了成功。两幅图像正常动画。但是，当我尝试动画三个以上的图像时，我面临着最终视频的问题。最终视频动画只有最后两张图片。我已粘贴代码段。

NSArray *imgArray = @[@"Logo3.png",@"Logo2.png",@"Logo1.png",@"Logo4.png",@"Logo5.png"];
 NSMutableArray *layers = [NSMutableArray new];
CGFloat timeOffset = 0.0f;

for (NSString *imgName in imgArray) {
    UIImage *animationImage = [UIImage imageNamed:imgName];
    CALayer *overlayLayer = [CALayer layer];
    [overlayLayer setContents:(id)[animationImage CGImage]];
    overlayLayer.frame = CGRectMake(10,  size.height/2 - 200, 103, 79);
    [overlayLayer setMasksToBounds:YES];


    CABasicAnimation *animation=[CABasicAnimation animationWithKeyPath:@"hidden"];
    animation.repeatCount=HUGE_VALF;
    //        animation.autoreverses=YES;
//        animation.cumulative = YES;

    // animate from invisible to fully visible
    animation.fromValue=[NSNumber numberWithFloat:1.0];
    animation.toValue=[NSNumber numberWithFloat:0.0];


//        animation.fillMode = kCAFillModeForwards;
        animation.beginTime = AVCoreAnimationBeginTimeAtZero + timeOffset;
        animation.duration = .5f;
        animation.removedOnCompletion = YES;
    [overlayLayer addAnimation:animation forKey:@"animateOpacity"];

    [layers addObject:overlayLayer];
    timeOffset += 0.5f;




}


CALayer *parentLayer = [CALayer layer];
CALayer *videoLayer = [CALayer layer];
parentLayer.frame = CGRectMake(0, 0, size.width, size.height);


videoLayer.frame = CGRectMake(0, 0, size.width, size.height);
    [parentLayer addSublayer:videoLayer];

  for (CALayer *layer in layers){
    [parentLayer addSublayer:layer];
}


composition.animationTool = [AVVideoCompositionCoreAnimationTool
                             videoCompositionCoreAnimationToolWithPostProcessingAsVideoLayer:videoLayer inLayer:parentLayer];

Answer 1

我怀疑你的问题就在这一行：

[overlayLayer addAnimation:animation forKey:@"animateOpacity"];

这里的“forKey”值实际上是动画名称的任意用户定义字符串。如果使用相同的密钥，则会覆盖以前的动画。尝试每次循环更改forKey名称。

CABasicAnimation的keyPath属性实际上是告诉动画要更改哪个属性。

在iOS中为视频中的图像添加动画

1 个答案: