改变导航栏的颜色 ios6.0 ios7

ios6

 [[UINavigationBar appearance] setBackgroundImage:[self createImageWithColor:[UIColor yellowColor]] forBarMetrics:UIBarMetricsDefault];

//这个是颜色转化图片-(UIImage *)createImageWithColor:(UIColor *)color{    CGRect rect = CGRectMake(0.0f, 0.0f, 1.0f, 1.0f);    UIGraphicsBeginImageContext(rect.size);    CGContextRef context = UIGraphicsGetCurrentContext();    CGContextSetFillColorWithColor(context, [color CGColor]);    CGContextFillRect(context, rect);    UIImage *theImage = UIGraphicsGetImageFromCurrentImageContext();    UIGraphicsEndImageContext();        return theImage;}

ios 7

[[UINavigationBar appearance] setBarTintColor:[UIColor yellowColor]];