ios 简单的文字字轨动画

因为本人不想弄gif图 所有就这样简陋的给大家看代码吧,最下面附上丑陋的代码。

一开始先写个全局属性

@property(nonatomic,strong)CAShapeLayer*shapeLayer;

接下来重点:

CGMutablePathRef letters =CGPathCreateMutable(); //保存所有文字的路径

NSAttributedString *str = [[NSAttributedStringalloc]initWithString:@“testtesttesttest”];

CTLineRef line =CTLineCreateWithAttributedString((CFAttributedStringRef)str);//获取str有多少行

CFArrayRef arrRef =CTLineGetGlyphRuns(line);//从一行中得到ref数组

获取完数组后便执行下面的代码:

接下来在循环外面写入下列代码:

CFRelease(line);

UIBezierPath*path = [UIBezierPathbezierPath];

[pathmoveToPoint:CGPointZero];

[path appendPath:[UIBezierPathbezierPathWithCGPath:letters]];

CGPathRelease(letters);

CAShapeLayer*pathLayer = [CAShapeLayerlayer];

pathLayer.frame=self.bounds;

pathLayer.bounds=CGPathGetBoundingBox(path.CGPath);

pathLayer.geometryFlipped=YES;

pathLayer.path= path.CGPath;

pathLayer.strokeColor= [self.colorCGColor];

pathLayer.fillColor=nil;

pathLayer.lineWidth=1;

pathLayer.lineJoin=kCALineJoinBevel;

self.shapeLayer= pathLayer;

self.shapeLayer.strokeEnd=0;

[self.layer addSublayer:self.shapeLayer];

记得 在layer中有个属性strokeEnd,这属性代表的是layer的完成度,圆形进度条也是利用这属性做的当strokeEnd = 0 时,layer将不显示,当为1时将显示完整，即我们可以：CABasicAnimation *pathAnimation = [CABasicAnimation animationWithKeyPath:@"strokeEnd"];

pathAnimation.fillMode=kCAFillModeForwards;

pathAnimation.removedOnCompletion=NO;

pathAnimation.duration=self.time;

pathAnimation.fromValue= [NSNumber numberWithFloat:self.startStrok];

pathAnimation.toValue= [NSNumber numberWithFloat:self.endStrok];

[self.shapeLayer addAnimation:pathAnimationforKey:@"strokeEnd"];

好的 大功告成了!
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