没啥知识点说的，就是利用UIBezierPath和CAShapeLayer划线，然后动画，直接贴代码。

@implementation LQYSuccessView
{
    UIView * _logoView;
}
- (instancetype)initWithFrame:(CGRect)frame withState:(BOOL)state
{
    self = [super initWithFrame:frame];
    if (self) {
        if (state) {
            [self drawSuccessLine];

        }else
        {
            [self drawFailLine];
 
        }
    }
    return self;
}

对勾方法

-(void)drawSuccessLine
{
    [_logoView removeFromSuperview];
    
    _logoView=[[UIView alloc]initWithFrame:self.frame];
    //曲线建立开始点和结束点
    //1. 曲线的中心
    //2. 曲线半径
    //3. 开始角度
    //4. 结束角度
    //5. 顺/逆时针方向
    UIBezierPath * path=[UIBezierPath bezierPathWithArcCenter:CGPointMake(self.centerX, self.centerY) radius:self.frame.size.width/2 startAngle:0 endAngle:M_PI*2 clockwise:YES];
    //对拐角和中心处理
    path.lineCapStyle=kCGLineCapRound;
    path.lineJoinStyle=kCGLineCapRound;
    
    
    //对号第一部分的起始
    
    [path moveToPoint:CGPointMake(self.frame.size.width/5, self.frame.size.width/2)];
    CGPoint pl =CGPointMake(self.frame.size.width/5*2, self.frame.size.width/4*3);
    [path addLineToPoint:pl];
    
    //对号第二部分起始
    CGPoint p2 = CGPointMake(self.frame.size.width/8.0*7, self.frame.size.width/4.0+8);
    [path addLineToPoint:p2];
    CAShapeLayer *layer = [[CAShapeLayer alloc] init];
    //内部填充颜色
    layer.fillColor = [UIColor clearColor].CGColor;
    //线条颜色
    layer.strokeColor = [UIColor colorWithHexString:@"60b0ff"].CGColor;
    //线条宽度
    layer.lineWidth = 5;
    layer.path = path.CGPath;
    //动画设置
    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:NSStringFromSelector(@selector(strokeEnd))];
    animation.fromValue = @0;
    animation.toValue = @1;
    animation.duration = 1;
    [layer addAnimation:animation forKey:NSStringFromSelector(@selector(strokeEnd))];
    
    [_logoView.layer addSublayer:layer];
    [self addSubview:_logoView];
                            
    
    
    
    
    
}

叉号方法

叉号和对号的区别就是调整一下会吐的起点和结束点

-(void)drawFailLine
{
    [_logoView removeFromSuperview];
    
    _logoView=[[UIView alloc]initWithFrame:self.frame];
    //曲线建立开始点和结束点
    //1. 曲线的中心
    //2. 曲线半径
    //3. 开始角度
    //4. 结束角度
    //5. 顺/逆时针方向
    UIBezierPath * path=[UIBezierPath bezierPathWithArcCenter:CGPointMake(self.centerX, self.centerY) radius:self.frame.size.width/2 startAngle:0 endAngle:M_PI*2 clockwise:YES];
    //对拐角和中心处理
    path.lineCapStyle=kCGLineCapRound;
    path.lineJoinStyle=kCGLineCapRound;
    
    
    //对号第一部分的起始
    
    [path moveToPoint:CGPointMake(self.frame.size.width/4, self.frame.size.width/4)];
    CGPoint pl =CGPointMake(self.frame.size.width/4*3, self.frame.size.width/4*3);
    [path addLineToPoint:pl];
    
    
    //对号第二部分起始

    [path moveToPoint:CGPointMake(self.frame.size.width/4*3, self.frame.size.width/4)];

    CGPoint p2 = CGPointMake(self.frame.size.width/4.0, self.frame.size.width/4*3);
    [path addLineToPoint:p2];
    
    CAShapeLayer *layer = [[CAShapeLayer alloc] init];
    //内部填充颜色
    layer.fillColor = [UIColor clearColor].CGColor;
    //线条颜色
    layer.strokeColor = [UIColor colorWithHexString:@"60b0ff"].CGColor;
    //线条宽度
    layer.lineWidth = 5;
    layer.path = path.CGPath;
    //动画设置
    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:NSStringFromSelector(@selector(strokeEnd))];
    animation.fromValue = @0;
    animation.toValue = @1;
    animation.duration = 1;
    [layer addAnimation:animation forKey:NSStringFromSelector(@selector(strokeEnd))];
    
    [_logoView.layer addSublayer:layer];
    [self addSubview:_logoView];
    

}

代码里用了YYKit 里面的属性，如果你项目里没有YYKit，修改一下self.centerX和self.centerX就行 。

具体项目地址请点击demo