iOS导航栏的背景颜色设置

1.默认

 self.navigationController.navigationBar.barStyle = UIBarStyleDefault;
 self.navigationController.navigationBar.translucent = YES;
 self.navigationController.navigationBar.tintColor = nil;

2.黑色不透明

   self.navigationController.navigationBar.barStyle = UIBarStyleBlack;
   self.navigationController.navigationBar.translucent = NO;
   self.navigationController.navigationBar.tintColor = [UIColor whiteColor];

3.黑色透明

  self.navigationController.navigationBar.barStyle = UIBarStyleBlack;
  self.navigationController.navigationBar.translucent = YES;
  self.navigationController.navigationBar.tintColor = [UIColor whiteColor];