这里我在CAKeyframeAnimation中显示一些具有固定持续时间1（总帧20，因此1/20 = 0.05f）的帧（.png）。它运行得很好。
- (void)animateImages
{
self.emoImageView = [[UIImageView alloc] initWithFrame:CGRectMake(100, 160, 50, 50)];
self.emoImageView.backgroundColor = [UIColor whiteColor];
[self.view addSubview:emoImageView];
NSArray *values = [NSArray arrayWithObjects:
(id)[UIImage imageNamed:@"smiley64_1_1.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_2.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_3.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_4.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_5.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_6.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_7.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_8.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_9.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_10.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_11.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_12.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_13.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_14.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_15.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_16.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_17.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_18.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_19.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_20.png"].CGImage, nil];
CAKeyframeAnimation *anim = [CAKeyframeAnimation animation];
//[anim setDuration:[[duration objectAtIndex:i] doubleValue]];
[anim setDuration:1];
[anim setValues:values];
[anim setKeyPath:@"contents"];
[anim setCalculationMode:@"discrete"];
[anim setRepeatCount: 90000];
[self.emoImageView.layer addAnimation:anim forKey:nil];
}
但是现在我想要显示具有不同持续时间的这些帧。我的NSArray有不同的持续时间值：
NSArray *duration = [NSArray arrayWithObjects:
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f], nil];
为此，我对它们使用了for loop，如下所示：
- (void)animateImages
{
self.emoImageView = [[UIImageView alloc] initWithFrame:CGRectMake(100, 160, 50, 50)];
self.emoImageView.backgroundColor = [UIColor whiteColor];
[self.view addSubview:emoImageView];
NSArray *values = [NSArray arrayWithObjects:
(id)[UIImage imageNamed:@"smiley64_1_1.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_2.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_3.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_4.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_5.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_6.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_7.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_8.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_9.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_10.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_11.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_12.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_13.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_14.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_15.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_16.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_17.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_18.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_19.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_20.png"].CGImage, nil];
NSArray *duration = [NSArray arrayWithObjects:
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f],
[NSNumber numberWithFloat:0.4f], nil];
for (int i = 0; i < [duration count]; i++)
{
CAKeyframeAnimation *anim = [CAKeyframeAnimation animation];
[anim setDuration:[[duration objectAtIndex:i] doubleValue]];
[anim setValues:@[[values objectAtIndex:i]]];
[anim setKeyPath:@"contents"];
[anim setCalculationMode:@"discrete"];
[anim setRepeatCount: 90000];
[self.emoImageView.layer addAnimation:anim forKey:nil];
}
}
但帧没有显示。如何在CAKeyframeAnimation中为具有不同持续时间的某些帧设置动画？
谢谢您的光临。
答案 0 :(得分：2)
你做得不对。不要在循环中创建多个关键帧动画。就像创建具有相同持续时间的动画一样，创建单个关键帧动画。但是，要逐帧控制持续时间，请将动画对象上的keyTimes属性设置为您创建的持续时间数组。
请注意，keyTimes的值是动画中每个帧的相对开始时间。它们的范围必须介于0.0到1.0之间，每个后续值必须大于最后一个值：
#define steps 20
NSMutableArray *startTimes = [NSMutableArray arrayWithCapacity: steps];
for (int i = 0; i< steps; i++)
{
startTimes[i] = @(i* 1.0/2.0);
}
您应该阅读CAKeyframeAnimation上的Xcode文档。他们实际上非常有用。
顺便说一句，每当你的代码一遍又一遍地完成同样的事情时，就值得考虑制作一个循环。就像加载图片一样：NSMutableArray *images = [NSMutableArray arrayWithCapacity: steps];
for (int i = 0; i< steps; i++)
{
//The filenames start at 1, so use i+1 to create the filename.
NSString *filename = [NSString stringWithFormat: @"smiley64_1_%d", i+1];
images[i] = (id)[UIImage imageNamed: filename].CGImage;
}
另请注意，您通常不应在对imageNamed的调用中包含文件扩展名。如果你不这样做，系统会以适当的分辨率（正常，@ 2x视网膜或@ 3x视网膜）加载图像。我相信包含明确的延伸会破坏这一点，尽管我并不积极。
从文档中读取此位：
数组中的每个值都是介于0.0和1.0之间的浮点数 定义时间点（指定为的分数 动画的总持续时间），在此处应用相应的 关键帧值。数组中的每个连续值必须更大 比以前的值更大或更等。通常，元素的数量 在数组中应该匹配值中的元素数量 属性或path属性中的控制点数。如果他们 不要，你的动画时间可能不是你所期望的。
答案 1 :(得分：0)
- (void)viewDidLoad
{
[super viewDidLoad];
self.durationArray = [[NSMutableArray alloc] initWithObjects:
@"0.04",
@"0.04",
@"0.04",
@"0.04",
@"0.04",
@"0.04",
@"0.04",
@"0.04",
@"0.04",
@"0.04",
@"0.04",
@"0.04",
@"0.04",
@"0.04",
@"0.04",
@"0.04",
@"0.04",
@"0.04",
@"0.04",
@"0.04", nil];
[self animateImages];
}
- (void)animateImages
{
self.emoImageView = [[UIImageView alloc] initWithFrame:CGRectMake(100, 160, 50, 50)];
self.emoImageView.backgroundColor = [UIColor whiteColor];
[self.view addSubview:emoImageView];
NSArray *values = [NSArray arrayWithObjects:
(id)[UIImage imageNamed:@"smiley64_1_1.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_2.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_3.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_4.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_5.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_6.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_7.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_8.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_9.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_10.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_11.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_12.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_13.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_14.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_15.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_16.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_17.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_18.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_19.png"].CGImage,
(id)[UIImage imageNamed:@"smiley64_1_20.png"].CGImage, nil];
// The total duration of my animation
float Duration = 0;
for (int i = 0; i < [durationArray count]; i++)
{
Duration = Duration + [[durationArray objectAtIndex: i] floatValue];
}
NSMutableArray *keyTimes = [[NSMutableArray alloc] init];
float keyTimesRow = 0.0;
for (int i = 0; i < [durationArray count]; i++)
{
keyTimesRow = keyTimesRow + ([[durationArray objectAtIndex: i] floatValue]/Duration);
NSNumber *k = [NSNumber numberWithFloat:keyTimesRow];
//keyTimes[0] = @(0.0);
[keyTimes addObject:k];
}
CAKeyframeAnimation *anim = [CAKeyframeAnimation animation];
[anim setDuration:Duration];
[anim setKeyTimes:keyTimes];
[anim setValues:values];
[anim setKeyPath:@"contents"];
[anim setRepeatCount: -1];
[self.emoImageView.layer addAnimation:anim forKey:nil];
}
这里我只计算动画的总持续时间。所以后者我可以用我的动画实例设置它。
// The total duration of my animation
float Duration = 0;
for (int i = 0; i < [durationArray count]; i++)
{
Duration = Duration + [[durationArray objectAtIndex: i] floatValue];
}
这里我从每帧的时间间隔创建KeyTimes数组。并创建keyTimes数组。
NSMutableArray *keyTimes = [[NSMutableArray alloc] init];
float keyTimesRow = 0.0;
for (int i = 0; i < [durationArray count]; i++)
{
keyTimesRow = keyTimesRow + ([[durationArray objectAtIndex: i] floatValue]/Duration);
NSNumber *k = [NSNumber numberWithFloat:keyTimesRow];
//keyTimes[0] = @(0.0);
[keyTimes addObject:k];
}
最后在动画实例中设置所有这些。
CAKeyframeAnimation *anim = [CAKeyframeAnimation animation];
[anim setDuration:Duration];
[anim setKeyTimes:keyTimes];
[anim setValues:values];
[anim setKeyPath:@"contents"];
[anim setRepeatCount: -1];
[self.emoImageView.layer addAnimation:anim forKey:nil];