iOS系统navigationBar背景色，文字颜色处理

- (void)setRightBarButtonItem
{
    // Create done Button
    UIBarButtonItem *doneButton = [[UIBarButtonItem alloc]initWithTitle:[NSString stringWithFormat:@"确定(%lu/%lu)", (unsigned long)self.selectedAssetURLs.count, (unsigned long)self.maximumNumberOfSelection] style:UIBarButtonItemStylePlain target:self action:@selector(done:)];

    [self.navigationItem setRightBarButtonItem:doneButton animated:YES];

    UIColor *color = [UIColor colorWithHexString:@"#fe5346"];
    CGRect frame = CGRectMake(0, 0, SCREEN_WIDTH, 64);
    UIImage *image = [UIImage imageWithColor:color withFrame:frame];
    [self.navigationController.navigationBar setBackgroundImage:image forBarMetrics:UIBarMetricsDefault];
    self.navigationController.navigationBar.tintColor    = [UIColor whiteColor];
    self.navigationController.navigationBar.barTintColor = [UIColor whiteColor];
    self.navigationController.navigationBar.titleTextAttributes = @{NSForegroundColorAttributeName : [UIColor whiteColor]};

}
- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    /**
     *  @author SongXing, 15-07-30 14:07:45
     *
     *  UIIMagePickerController颜色修正
     *
     */
    if ([navigationController isKindOfClass:[UIImagePickerController class]] &&
        ((UIImagePickerController *)navigationController).sourceType ==     UIImagePickerControllerSourceTypePhotoLibrary) {
        [[UIApplication sharedApplication] setStatusBarHidden:NO];
        [[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent animated:NO];
    }

    if (navigationController.viewControllers.count != 3) return;

    CGFloat screenHeight = [[UIScreen mainScreen] bounds].size.height;

    UIView *plCropOverlay = [viewController.view.subviews[1] subviews][0];

    plCropOverlay.hidden = YES;

    int position = 0;

    position = (screenHeight == 568) ? 124 : 80;

    CAShapeLayer *circleLayer = [CAShapeLayer layer];

    UIBezierPath *path2 = [UIBezierPath bezierPathWithOvalInRect:
                           CGRectMake(0.0f, position, SCREEN_WIDTH, 320.0f)];
    [path2 setUsesEvenOddFillRule:YES];

    [circleLayer setPath:[path2 CGPath]];

    [circleLayer setFillColor:[[UIColor clearColor] CGColor]];
    UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(0, 0, SCREEN_WIDTH, screenHeight-72) cornerRadius:0];

    [path appendPath:path2];
    [path setUsesEvenOddFillRule:YES];

    CAShapeLayer *fillLayer = [CAShapeLayer layer];
    fillLayer.path = path.CGPath;
    fillLayer.fillRule = kCAFillRuleEvenOdd;
    fillLayer.fillColor = [UIColor clearColor].CGColor;
    fillLayer.opacity = 0.8;
    [viewController.view.layer addSublayer:fillLayer];

}