【发布时间】：2015-01-22 19:12:29
【问题描述】：
我创建了一个播放单个音频的简单音频播放器。视图显示 CAShapeLayer 循环进度，还显示使用 CATextLayer 的当前时间。下图显示，视图：
到目前为止一切正常，我可以播放、暂停并且 CAShapeLayer 显示进度。现在，我想做到这一点，当我触摸 CAShapeLayer 路径的笔触（轨道）部分时，我想寻找那个时间的玩家。我尝试了几种方法，但我无法检测到笔画所有部分的触摸。我所做的计算似乎不太合适。如果有人能帮我解决这个问题，我会非常高兴。
这是我的完整代码，
@interface ViewController ()
@property (nonatomic, weak) CAShapeLayer *progressLayer;
@property (nonatomic, weak) CAShapeLayer *trackLayer;
@property (nonatomic, weak) CATextLayer *textLayer;
@property (nonatomic, strong) AVAudioPlayer *audioPlayer;
@property (nonatomic, weak) NSTimer *audioPlayerTimer;
@end
@implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
[self prepareLayers];
[self prepareAudioPlayer];
[self prepareGestureRecognizers];
}
- (void)prepareLayers
{
CGFloat lineWidth = 40;
CGRect shapeRect = CGRectMake(0,
0,
CGRectGetWidth(self.view.bounds),
CGRectGetWidth(self.view.bounds));
CGRect actualRect = CGRectInset(shapeRect, lineWidth / 2.0, lineWidth / 2.0);
CGPoint center = CGPointMake(CGRectGetMidX(actualRect), CGRectGetMidY(actualRect));
CGFloat radius = CGRectGetWidth(actualRect) / 2.0;
UIBezierPath *track = [UIBezierPath bezierPathWithArcCenter:center
radius:radius
startAngle:0 endAngle:2 * M_PI
clockwise:true];
UIBezierPath *progressLayerPath = [UIBezierPath bezierPathWithArcCenter:center
radius:radius
startAngle:-M_PI_2
endAngle:2 * M_PI - M_PI_2
clockwise:true];
progressLayerPath.lineWidth = lineWidth;
CAShapeLayer *trackLayer = [CAShapeLayer layer];
trackLayer.contentsScale = [UIScreen mainScreen].scale;
trackLayer.shouldRasterize = YES;
trackLayer.rasterizationScale = [UIScreen mainScreen].scale;
trackLayer.bounds = actualRect;
trackLayer.strokeColor = [UIColor lightGrayColor].CGColor;
trackLayer.fillColor = [UIColor whiteColor].CGColor;
trackLayer.position = self.view.center;
trackLayer.lineWidth = lineWidth;
trackLayer.path = track.CGPath;
self.trackLayer = trackLayer;
CAShapeLayer *progressLayer = [CAShapeLayer layer];
progressLayer.contentsScale = [UIScreen mainScreen].scale;
progressLayer.shouldRasterize = YES;
progressLayer.rasterizationScale = [UIScreen mainScreen].scale;
progressLayer.masksToBounds = NO;
progressLayer.strokeEnd = 0;
progressLayer.bounds = actualRect;
progressLayer.fillColor = nil;
progressLayer.path = progressLayerPath.CGPath;
progressLayer.position = self.view.center;
progressLayer.lineWidth = lineWidth;
progressLayer.lineJoin = kCALineCapRound;
progressLayer.lineCap = kCALineCapRound;
progressLayer.strokeColor = [UIColor redColor].CGColor;
CATextLayer *textLayer = [CATextLayer layer];
textLayer.contentsScale = [UIScreen mainScreen].scale;
textLayer.shouldRasterize = YES;
textLayer.rasterizationScale = [UIScreen mainScreen].scale;
textLayer.font = (__bridge CTFontRef)[UIFont systemFontOfSize:30.0];
textLayer.position = self.view.center;
textLayer.bounds = CGRectMake(0, 0, 300, 100);
[self.view.layer addSublayer:trackLayer];
[self.view.layer addSublayer:progressLayer];
[self.view.layer addSublayer:textLayer];
self.trackLayer = trackLayer;
self.progressLayer = progressLayer;
self.textLayer = textLayer;
[self displayText:@"Play"];
}
- (void)prepareAudioPlayer
{
NSError *error;
self.audioPlayer = [[AVAudioPlayer alloc]
initWithContentsOfURL:[[NSBundle mainBundle] URLForResource:@"Song" withExtension:@"mp3"]
error:&error];
self.audioPlayer.volume = 0.2;
if (!self.audioPlayer) {
NSLog(@"Error occurred, could not create audio player");
return;
}
[self.audioPlayer prepareToPlay];
}
- (void)prepareGestureRecognizers
{
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self
action:@selector(playerViewTapped:)];
[self.view addGestureRecognizer:tap];
}
- (void)playerViewTapped:(UITapGestureRecognizer *)tap
{
CGPoint tappedPoint = [tap locationInView:self.view];
if ([self.view.layer hitTest:tappedPoint] == self.progressLayer) {
CGPoint locationInProgressLayer = [self.view.layer convertPoint:tappedPoint toLayer:self.progressLayer];
NSLog(@"Progress view tapped %@", NSStringFromCGPoint(locationInProgressLayer));
// this is called sometimes but not always when I tap the stroke
} else if ([self.view.layer hitTest:tappedPoint] == self.textLayer) {
if ([self.audioPlayer isPlaying]) {
[self.audioPlayerTimer invalidate];
[self displayText:@"Play"];
[self.audioPlayer pause];
} else {
[self.audioPlayer play];
self.audioPlayerTimer = [NSTimer scheduledTimerWithTimeInterval:1.0
target:self
selector:@selector(increaseProgress:)
userInfo:nil
repeats:YES];
}
}
}
- (void)increaseProgress:(NSTimer *)timer
{
NSTimeInterval currentTime = self.audioPlayer.currentTime;
NSTimeInterval totalDuration = self.audioPlayer.duration;
float progress = currentTime / totalDuration;
self.progressLayer.strokeEnd = progress;
int minute = ((int)currentTime) / 60;
int second = (int)currentTime % 60;
NSString *progressString = [NSString stringWithFormat:@"%02d : %02d ", minute,second];
[self displayText:progressString];
}
- (void)displayText:(NSString *)text
{
UIColor *redColor = [UIColor redColor];
UIFont *font = [UIFont fontWithName:@"HelveticaNeue" size:70];
NSDictionary *attribtues = @{
NSForegroundColorAttributeName: redColor,
NSFontAttributeName: font,
};
NSAttributedString *progressAttrString = [[NSAttributedString alloc] initWithString:text
attributes:attribtues];
self.textLayer.alignmentMode = kCAAlignmentCenter;
self.textLayer.string = progressAttrString;
}
- (void)viewWillTransitionToSize:(CGSize)size
withTransitionCoordinator:(id<UIViewControllerTransitionCoordinator>)coordinator
{
[super viewWillTransitionToSize:size withTransitionCoordinator:coordinator];
void(^animationBlock)(id<UIViewControllerTransitionCoordinatorContext>) =
^(id<UIViewControllerTransitionCoordinatorContext> context) {
CGRect rect = (CGRect){.origin = CGPointZero, .size = size};
CGPoint center = CGPointMake(CGRectGetMidX(rect), CGRectGetMidY(rect));
self.progressLayer.position = center;
self.textLayer.position = center;
self.trackLayer.position = center;
};
[coordinator animateAlongsideTransitionInView:self.view
animation:animationBlock completion:nil];
}
@end
【问题讨论】：
标签： ios graphics core-animation