iOS开发：设置纯色导航栏，去掉导航栏分割线

1、实现方法：生成纯色图片

- (UIImage *)imageWithColor:(UIColor *)color {

    CGRect rect = CGRectMake(0.0f, 0.0f, 1.0f, 1.0f);

    UIGraphicsBeginImageContext(rect.size);

    CGContextRef context = UIGraphicsGetCurrentContext();