UINavigation自定义返回按钮

UIButton *imageButton = [UIButton buttonWithType:UIButtonTypeCustom];
[imageButton setFrame:CGRectMake(15, 0, 57, 44)];
[imageButton setBackgroundImage:[UIImage imageNamed:@"someImage.png"] forState:UIControlStateNormal];


UILabel *titleLabel = [[UILabel alloc] initWithFrame:CGRectMake(140, 0, 250, 44)];
[titleLabel setText:@"some title"];
[titleLabel setBackgroundColor:[UIColor clearColor]];
[titleLabel setTextColor:[UIColor whiteColor]];
[titleLabel setFont:[UIFont boldSystemFontOfSize:20]];

[self.navigationController.navigationBar addSubview:imageButton];
[self.navigationController.navigationBar addSubview:titleLabel];

self.navigationItem.leftBarButtonItem = nil;