ios控件渐变色的处理

+(CAGradientLayer *)gradientColorWithBounds:(CGRect)bounds startColorHexString:(NSString *)startColor endColorHexString:(NSString *)endColor {
    CAGradientLayer *gradientLayer = [CAGradientLayer layer];
    gradientLayer.colors = @[(__bridge id)[UIColor colorWithHexString:startColor].CGColor, (__bridge id)[UIColor colorWithHexString:endColor].CGColor];
    gradientLayer.locations = @[@0, @1];
    gradientLayer.startPoint = CGPointMake(0, 0);
    gradientLayer.endPoint = CGPointMake(1.0, 1.0);
    gradientLayer.frame = bounds;
    return gradientLayer;
}