将水波效果放在子视图上，主控制器只负责加载
#import "WaveProgress.h"
@interface WaveProgress ()
@property (nonatomic,assign)CGFloat yHeight;/**< 当前进度对应的y值,由于y是向下递增,所以要注意 */
@property (nonatomic,assign)CGFloat offset;/**< 偏移量,决定了这个点在y轴上的位置,以此来实现动态效果*/
@property (nonatomic,strong)CADisplayLink * link;/**< 定时器*/
@property (nonatomic,strong)CAShapeLayer * waveLayer;/**< 水波的layer */
@property (nonatomic,assign)CGFloat speed;/**< 波动的速度*/
@property (nonatomic,strong)UIColor * waveColor;
@property (nonatomic,assign)CGFloat waveHeight;
@end
@implementation WaveProgress
- (instancetype)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
self.layer.borderColor = [UIColor lightGrayColor].CGColor;
self.layer.borderWidth = 1.0f;
self.waveHeight = 5.0;
self.speed = 1.0;
self.waveColor = [UIColor greenColor];
self.waveLayer = [CAShapeLayer layer];
self.waveLayer.frame = self.bounds;
self.waveLayer.fillColor = [UIColor whiteColor].CGColor;
[self.layer addSublayer:self.waveLayer];
//由于y坐标轴的方向是由上向下,逐渐增加的,所以这里对于y坐标进行处理
self.yHeight = self.bounds.size.height * 0.2;
//先停止动画,然后在开始动画,保证不会有什么冲突和重复.
[self stopWaveAnimation];
[self startWaveAnimation];
}
return self;
}
#pragma mark -- 开始波动动画
- (void)startWaveAnimation
{
//相对于NSTimer CADisplayLink更准确,每一帧调用一次.
self.link = [CADisplayLink displayLinkWithTarget:self selector:@selector(waveAnimation)];
[self.link addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSRunLoopCommonModes];
}
#pragma mark -- 停止波动动画
- (void)stopWaveAnimation
{
[self.link invalidate];
self.link = nil;
}
#pragma mark -- 波动动画实现
- (void)waveAnimation
{
CGFloat waveHeight = self.waveHeight;
//如果是0或者1,则不需要wave的高度,否则会看出来一个小的波动.
// if (self.progress == 0.0f || self.progress == 1.0f) {
// waveHeight = 0.f;
// }
//累加偏移量,这样就可以通过speed来控制波动的速度了.对于正弦函数中的各个参数,你可以通过上面的注释进行了解.
self.offset += self.speed;
CGMutablePathRef pathRef = CGPathCreateMutable();
CGFloat startOffY = waveHeight * sinf(self.offset * M_PI * 2 / self.bounds.size.width);
CGFloat orignOffY = 0.0;
CGPathMoveToPoint(pathRef, NULL, 0, startOffY);
for (CGFloat i = 0.f; i <= self.bounds.size.width; i++) {
orignOffY = waveHeight * sinf(2 * M_PI / self.bounds.size.width * i + self.offset * M_PI * 2 / self.bounds.size.width) + self.yHeight;
CGPathAddLineToPoint(pathRef, NULL, i, orignOffY);
}
//连接四个角和以及波浪,共同组成水波.
CGPathAddLineToPoint(pathRef, NULL, self.bounds.size.width, orignOffY);
CGPathAddLineToPoint(pathRef, NULL, self.bounds.size.width, self.bounds.size.height);
CGPathAddLineToPoint(pathRef, NULL, 0, self.bounds.size.height);
CGPathAddLineToPoint(pathRef, NULL, 0, startOffY);
CGPathCloseSubpath(pathRef);
self.waveLayer.path = pathRef;
self.waveLayer.fillColor = self.waveColor.CGColor;
CGPathRelease(pathRef);
}
@end
在主控制器中就懒加载一次就可以
- (WaveProgress *)progressView
{
if (!_progressView) {
_progressView = [[WaveProgress alloc]initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, 150)];
}
return _progressView;
}
效果图如下