搜索框，导航栏随页面滑动渐变

简单的变化

#pragma mark - scrollViewDelegate
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    CGFloat alpha = scrollView.contentOffset.y / 100;
    if (alpha >= 1) {
        alpha = 1;
    }else if (alpha <= 0)
    {
        alpha = 0;
    }
    self.naviView.backgroundColor = [UIcolor colorWithAlphaComponent:alpha];
}

//一些更多的变化

- (void)scrollViewDidScroll:(UIScrollView *)scrollView{
    if (scrollView == self.myTableView) {
        if (scrollView.contentOffset.y<(200-_homeView.mj_h)){
            float alpha = scrollView.contentOffset.y/(200-_homeView.mj_h);
            _homeView.backgroundColor = [[UIColor whiteColor]colorWithAlphaComponent:alpha];
            if (alpha>0.5) {
                if(!CGColorEqualToColor(self.titleView.backgroundColor.CGColor, [UIColor colorHexString:@"#efefef"].CGColor)){
                    [[UIApplication sharedApplication]setStatusBarStyle:UIStatusBarStyleDefault animated:NO];
                    self.telButton.buttonImageView.image = [UIImage imageNamed:@"sy_kf_hei_icon"];
                    self.telButton.titleLabel.textColor = [UIColor colorHexString:@"#3d3d3d"];
                    self.titleView.backgroundColor = [UIColor colorHexString:@"#efefef"];
                    self.messageLabel.textColor = [UIColor colorHexString:@"#3d3d3d"];
                    [self.messageButtonItem setImage:[UIImage imageNamed:@"zjwd_db_ssk_xx_icon"] forState:UIControlStateNormal];
                }
            }
            else{
                if(!CGColorEqualToColor(self.titleView.backgroundColor.CGColor, [UIColor whiteColor].CGColor)){
                    [[UIApplication sharedApplication]setStatusBarStyle:UIStatusBarStyleLightContent animated:NO];
                    self.telButton.buttonImageView.image = [UIImage imageNamed:@"sy_kf_bai_icon"];
                    self.telButton.titleLabel.textColor = [UIColor colorHexString:@"#ffffff"];
                    self.titleView.backgroundColor = [UIColor whiteColor];
                    self.messageLabel.textColor = [UIColor colorHexString:@"#ffffff"];
                    [self.messageButtonItem setImage:[UIImage imageNamed:@"sy_xx_bai_icon"] forState:UIControlStateNormal];
                }
            }
            
        }
        else
        {
            _homeView.backgroundColor = [[UIColor whiteColor]colorWithAlphaComponent:1.0f];
            if(!CGColorEqualToColor(self.titleView.backgroundColor.CGColor, [UIColor colorHexString:@"#efefef"].CGColor)){
                [[UIApplication sharedApplication]setStatusBarStyle:UIStatusBarStyleDefault animated:NO];
                self.telButton.buttonImageView.image = [UIImage imageNamed:@"sy_kf_hei_icon"];
                self.telButton.titleLabel.textColor = [UIColor colorHexString:@"#3d3d3d"];
                self.titleView.backgroundColor = [UIColor colorHexString:@"#efefef"];
                self.messageLabel.textColor = [UIColor colorHexString:@"#3d3d3d"];
                [self.messageButtonItem setImage:[UIImage imageNamed:@"zjwd_db_ssk_xx_icon"] forState:UIControlStateNormal];
            }
        }
    }
}