1.創(chuàng)建layer
_shapeLayer= [CAShapeLayer layer];
_shapeLayer.frame=CGRectMake(0,100,375,150);
[self.view.layeraddSublayer:_shapeLayer];
_shapeLayer2= [CAShapeLayer layer];
_shapeLayer2.frame = CGRectMake(0,100,375,150);
[self.view.layer addSublayer:_shapeLayer2];
2.創(chuàng)建定時器
_displayLink = [CADisplayLink displayLinkWithTarget:selfselector:@selector(drawPath)];
[_displayLink addToRunLoop:[NSRunLoopmainRunLoop] forMode:NSRunLoopCommonModes];
3.drawPath方法
static doublei =0;
CGFloat A =10.f;//A振幅
CGFloat k =0;//y軸偏移
CGFloat ω = 0.03;//角速度ω變大，則波形在X軸上收縮（波形變緊密）；角速度ω變小，則波形在X軸上延展（波形變稀疏）。不等于0
CGFloat φ = 0 + i;//初相，x=0時的相位；反映在坐標(biāo)系上則為圖像的左右移動。
//y=Asin(ωx+φ)+k
_path= [UIBezierPath bezierPath];
_path2= [UIBezierPath bezierPath];
[_path moveToPoint:CGPointZero];
[_path2 moveToPoint:CGPointZero];
for(int i =0; i < 376; i ++) {
CGFloat x = i;
CGFloat y = A *sin(ω*x+φ)+k;
CGFloat y2 = A *cos(ω*x+φ)+k;
[_path addLineToPoint:CGPointMake(x, y)];
[_path2 addLineToPoint:CGPointMake(x, y2)];
}
[_path addLineToPoint:CGPointMake(375, -100)];
[_path addLineToPoint:CGPointMake(0, -100)];
_path.lineWidth = 1;
_shapeLayer.path = _path.CGPath;
[_path2 addLineToPoint:CGPointMake(375, -100)];
[_path2 addLineToPoint:CGPointMake(0, -100)];
_path2.lineWidth = 1;
_shapeLayer2.path = _path2.CGPath;
i +=0.1;
if(i >M_PI*2) {
i =0;//防止i越界
}
4.效果圖
玩一個有趣的效果，漸變色：
demo已更新代碼，這里就不貼代碼了
