iOS：无法更改UIBarButtonItem的颜色

Question

我基本上有一个ViewController，它是UINavigationController的根ViewController。基本上我有一个UIBarButtonItem，当用户按下它时，它的色调应该在红色和绿色之间切换。但颜色似乎没有改变。我的代码：

@interface TestButtonColorViewController (){
    BOOL colorMode;
}
@end

@implementation TestButtonColorViewController

- (void)viewDidLoad
{
    [super viewDidLoad];

    colorMode = NO;

    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Change" style:UIBarButtonItemStyleBordered target:self action:@selector(changeColor)];


}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (void)changeColor{
    colorMode = !colorMode;

    if (colorMode) {
        [[UIBarButtonItem appearanceWhenContainedIn:[UINavigationBar class], nil] setTintColor:[UIColor redColor]];
    }
    else {
        [[UIBarButtonItem appearanceWhenContainedIn:[UINavigationBar class], nil] setTintColor:[UIColor greenColor]];
    }
}

Answer 1

正如CSmith建议的那样，你应该直接设置色调：

- (void)changeColor {
    colorMode = !colorMode;

    if (colorMode) {
        [self.navigationItem.rightBarButtonItem setTintColor:[UIColor redColor]];
    } else {
        [self.navigationItem.rightBarButtonItem setTintColor:[UIColor greenColor]];
    }
}