ios 把navigationController.navigationBar 下面的黑线去掉

- (void)viewWillAppear:(BOOL)animated{

[super viewWillAppear:YES];

[self.navigationController.navigationBar setBackgroundImage:[UIImage imageNamed:@"head_bar_pink_.png"] forBarMetrics:UIBarMetricsDefault];

[self.navigationController.navigationBar setShadowImage:[self createImageWithColor:[UIColor clearColor]]];

}

- (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;

}