iOS - 按钮添加渐变色背景

1.效果：

2.代码：

        CAGradientLayer *gl = [CAGradientLayer layer];
        gl.frame = CGRectMake(0,0,66,30);
        gl.startPoint = CGPointMake(0, 0.5);
        gl.endPoint = CGPointMake(1, 0.5);
        gl.colors = @[(__bridge id)[UIColor colorWithRed:255/255.0 green:164/255.0 blue:7/255.0 alpha:1.0].CGColor,(__bridge id)[UIColor colorWithRed:254/255.0 green:64/255.0 blue:78/255.0 alpha:1.0].CGColor];
        gl.locations = @[@(0),@(1.0f)];
        [self.btn.layer addSublayer:gl];