设置部分圆角~一个渐变色圆弧

 UIView *view2 = [[UIView alloc] initWithFrame:CGRectMake(120, 10, 80, 80)];
    view2.backgroundColor = [UIColor redColor];
    [self.view addSubview:view2];
    
    UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:view2.bounds byRoundingCorners:UIRectCornerBottomLeft | UIRectCornerBottomRight cornerRadii:CGSizeMake(10, 10)];
    CAShapeLayer *maskLayer = [[CAShapeLayer alloc] init];
    maskLayer.frame = view2.bounds;
    maskLayer.path = maskPath.CGPath;
    view2.layer.mask = maskLayer;

 

 

 

    CAShapeLayer *layer = [CAShapeLayer layer];
    layer.fillColor = [[UIColor clearColor] CGColor];
    layer.strokeColor = [[UIColor greenColor] CGColor];
//    layer.backgroundColor = [[UIColor clearColor] CGColor];
    layer.lineJoin = kCALineJoinRound;
    layer.lineCap = kCALineCapRound;
    layer.frame = self.view.bounds;
    layer.lineWidth =  100.0f;
    //layer.strokeColor = [UIColor redColor].CGColor;
    //[self.view.layer addSublayer:layer];
    //CAGradientLayer
    
   
    //layer.masksToBounds = YES;
    
    
    
    //CAGradientLayer *gLayer = [CAGradientLayer layer];
    CAGradientLayer *topLayer = [[CAGradientLayer alloc] init];
    topLayer.startPoint = CGPointMake(0.0, 1);
    topLayer.endPoint = CGPointMake(0.0f, 0.0f);
    topLayer.colors = @[(id)[UIColor colorWithRed:1 green:0 blue:0 alpha:1 ].CGColor,(id)[UIColor colorWithRed:0 green:0 blue:1 alpha:1].CGColor];
    topLayer.frame = self.view.bounds;

    
    
    
    UIBezierPath *path = [UIBezierPath bezierPath];
    [path addArcWithCenter:self.view.center radius:160 startAngle:M_PI/2 endAngle:M_PI*2 clockwise:YES];
//    [path moveToPoint:CGPointMake(10, 100)];
//    [path addLineToPoint:CGPointMake(100, 200)];
//    [path addLineToPoint:CGPointMake(200, 50)];
//    [path addLineToPoint:CGPointMake(240, 150)];
//    [path addLineToPoint:CGPointMake(300, 120)];
    //gLayer.
    
    
    // 关联layer和贝塞尔路径~
    layer.path = path.CGPath;
    
    //[layer addSublayer:topLayer];
    topLayer.mask = layer;
    [self.view.layer addSublayer:topLayer];
    
    
    layer.strokeEnd = 0.7;
    //[self.view.layer addSublayer:layer];