禁用的 uibarbuttonitem 的文本颜色始终是正常状态的颜色

我在我的代码中写道

[[UIBarButtonItem appearanceWhenContainedIn:[UINavigationBar class], nil]  setTitleTextAttributes:@{NSForegroundColorAttributeName : [UIColor lightGrayColor], NSFontAttributeName:[UIFont boldSystemFontOfSize:16.0f]} forState:UIControlStateDisabled];

[[UIBarButtonItem appearanceWhenContainedIn:[UINavigationBar class], nil]  setTitleTextAttributes:@{NSForegroundColorAttributeName : [UIColor blueColor], NSFontAttributeName:[UIFont boldSystemFontOfSize:16.0f]} forState:UIControlStateNormal];

但尽管 baritem 被禁用，文本颜色始终为蓝色。

我正在 xcode 5 和 ios7 中编程

对我来说code works.

- (void)viewDidLoad {
    [super viewDidLoad];

    UIBarButtonItem * btnTemp = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(btnDone_Click:)];
    [btnTemp setTitleTextAttributes:@{NSForegroundColorAttributeName : [UIColor lightGrayColor], NSFontAttributeName:[UIFont boldSystemFontOfSize:16.0f]} forState:UIControlStateNormal];

    [btnTemp setTitleTextAttributes:@{NSForegroundColorAttributeName : [UIColor blueColor], NSFontAttributeName:[UIFont systemFontOfSize:16.0f]} forState:UIControlStateDisabled];


    [self.navigationItem setRightBarButtonItem:btnTemp];

}

- (void)btnDone_Click : (id)sender {

    UIBarButtonItem * button = (UIBarButtonItem *)sender;
    [button setEnabled:FALSE];
    [self performSelector:@selector(enableButton:) withObject:sender afterDelay:2.0f];


}

- (void)enableButton : (id)sender {
    UIBarButtonItem * button = (UIBarButtonItem *)sender;
    [button setEnabled:TRUE];
}