Question

为什么无法设置 UIBarButtonItem Disabled状态的颜色

Answer 1

应该使用
javascript[[UIBarButtonItem appearance] setTitleTextAttributes:@{NSForegroundColorAttributeName:[UIColor redColor]} forState:UIControlStateDisabled];

参照UIBarItem.h里面的
javascript
- (void)setTitleTextAttributes:(NSDictionary *)attributes forState:(UIControlState)state NS_AVAILABLE_IOS(5_0) UI_APPEARANCE_SELECTOR;
- (NSDictionary *)titleTextAttributesForState:(UIControlState)state NS_AVAILABLE_IOS(5_0) UI_APPEARANCE_SELECTOR;

这两个方法是Appearance protocol的方法。
应该是调用方法的时间点上有问题，这个是我的demo代码片段
javascript- (instancetype)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];

if (self) {
[self setNaviagtionItem];
}

return self;
}

- (instancetype)init
{
self = [super init];

if (self) {
[self setNaviagtionItem];
}

return self;
}

- (id)initWithCoder:(NSCoder *)aDecoder
{
self = [super initWithCoder:aDecoder];

if (self) {
[self setNaviagtionItem];
}

return self;
}

- (void)setNaviagtionItem
{
UIBarButtonItem *leftItem = [[UIBarButtonItem alloc] initWithTitle:@"bb"style:UIBarButtonItemStyleDone target:self action:nil];
self.navigationItem.leftBarButtonItem = leftItem;

NSDictionary* textAttributes = [NSDictionary dictionaryWithObject: [UIColor blackColor]
forKey: NSForegroundColorAttributeName];

[[UIBarButtonItem appearance] setTitleTextAttributes: textAttributes
forState: UIControlStateNormal];

NSDictionary* textAttributes1 = [NSDictionary dictionaryWithObject: [UIColor brownColor]
forKey: NSForegroundColorAttributeName];
[[UIBarButtonItem appearance] setTitleTextAttributes: textAttributes1
forState: UIControlStateDisabled];

NSDictionary* textAttributes2 = [NSDictionary dictionaryWithObject: [UIColor yellowColor]
forKey: NSForegroundColorAttributeName];
[[UIBarButtonItem appearance] setTitleTextAttributes: textAttributes2
forState: UIControlStateSelected];
}

- (void)viewDidLoad {
[super viewDidLoad];
[self setNaviagtionItem];

self.navigationItem.leftBarButtonItem.enabled = NO;
}