ios iphone ipad 开发应用内实现多语言自由切换 超级好用

最近几个app都有在应用实现多种语言自由切换的需求，不是那种随着设备语言设置而改变自身应用语言的那种，相对而言，自由切换更麻烦一些，不过我现在将其封装成一个专用类，实现起来就非常非常方便了，供有相同需求的朋友参考使用。欢迎各位留言讨论指正，转载请注明出处。谢谢！

http://blog.youkuaiyun.com/gghu1986/article/details/8464450

类名为：LanguageController

.h文件：
#import <Foundation/Foundation.h>
#define LANGUAGE_STATE_NOTIFICATION   @"LANGUAGE_STATE_NOTIFICATION"
#define LANGUAGE_STATE                @"LANGUAGE_STATE"
@protocol LanguageControllerDelegate<NSObject>
@required
@optional
-(void)updateLanguage;
@end
@interface LanguageController : NSObject{
    id<LanguageControllerDelegate>         _delegate;
}
@property(nonatomic,assign) id<LanguageControllerDelegate> delegate;
+(LanguageController *)languageController;
-(void)setDelegate:(id<LanguageControllerDelegate>)delegate;
@end

.m文件：
#import "LanguageController.h"
static LanguageController *languageController =nil;
@implementation LanguageController
@synthesize delegate = _delegate;
+(LanguageController *)languageController
{
    @synchronized(self){
        if (languageController == nil) {
            languageController = [[LanguageController alloc] init];
        }
    }
    return languageController;
}
-(void)setDelegate:(id<LanguageControllerDelegate>)delegate{
    _delegate = delegate;
    [[NSNotificationCenterdefaultCenter] addObserver:selfselector:@selector(languageChanged:)name:LANGUAGE_STATE_NOTIFICATIONobject:nil];
}
-(void) languageChanged:(id) sender{
    if(_delegate !=nil && [_delegate respondsToSelector:@selector(updateLanguage)]) {
        [_delegateupdateLanguage];
    }
}
- (void)dealloc {
      [[NSNotificationCenterdefaultCenter] removeObserver:selfname:LANGUAGE_STATE_NOTIFICATIONobject:nil];
     _delegate=nil;
     [superdealloc];
}
@end

将以上两个文件加入到工程后，使用时就非常方便了，首先在更改语言的按钮事件中添加语言切换通知语句：

[[NSNotificationCenter defaultCenter] postNotificationName:LANGUAGE_STATE_NOTIFICATION object:nil];

然后在所有需要刷新页面的viewController的viewDidLoad函数中加入设置代理的语句：

[LanguageController languageController].delegate = self;

再在这些viewController类中实现LanguageControllerDelegate的方法-(void)updateLanguage;所有因语言切换而需要更新或刷新的工作都放着这个代理方法中实现即可。

好了，看完你只要将上面的.h和.m文件加入到自己的工程中，再加上上面提到的几行代码，就可以了，是不是很方便呢