实现过程

1. 项目中建立存放国际化文件的bundle，bundle里面包含各种语言的string文件。
   bundle文件结构
   2.建立存放国际化key的常量文件。
   常量文件
   3.获取系统的语言首选项
   NSString *language = [NSLocale preferredLanguages].firstObject;，再通过

 NSString *bundlePath = [[NSBundle mainBundle] pathForResource:bundle ofType:@"bundle"];
languageBundle = [NSBundle bundleWithPath:[[NSBundle bundleWithPath:bundlePath] pathForResource:language ofType:@"lproj"]];

拿到对应语言的bundle，最后通过

NSString *vv = [languageBundle localizedStringForKey:self value:value table:table];
```获取到string里面对应key的字符串。
4.通过给NSString添加分类达到使用点语言获取到对应的字符串。
` [M1905TipView showMessage:kChairIsEndError.value];`

### 分类文件
1.NSString+Localizable.h

import <Foundation/Foundation.h>

//语言bundle文件名字
static NSString *const defaultBundle = @"Bizaia";

@interface NSString (Localizable)
@property (nonatomic, strong ,readonly) NSString *value;

• (NSString *)valueByBundleName:(NSString *)bundle;
• (NSString *)valueByBundleName:(NSString *)bundle language:(NSString *)language defaultValue:(NSString *)value;
• (NSString *)valueByBundleName:(NSString *)bundle language:(NSString *)language defaultValue:(NSString *)value table:(NSString *)table;
  @end

2.NSString+Localizable.m

import "NSString+Localizable.h"

static NSMutableDictionary *bundleDic = nil;
static NSString *language = nil;

FOUNDATION_STATIC_INLINE NSString *getLanguage(){
if (language) {
return language;
}
NSString *language = [NSLocale preferredLanguages].firstObject;
if ([language hasPrefix:@"en"]) {
language = @"en";
} else if ([language hasPrefix:@"zh"]) {
language = @"zh-Hans";
} else if([language hasPrefix:@"ja"]){
language = @"ja";
}else {
language = @"zh-Hans";
}
return language;
}

@implementation NSString (Localizable)

• (void)load{
  if (!bundleDic) {
  bundleDic = [NSMutableDictionary dictionary];
  }
  if (!language) {
  language = getLanguage();
  }
  }

• (NSString *)value{
  return [self valueByBundleName:defaultBundle];
  }

• (NSString *)valueByBundleName:(NSString *)bundle{
  return [self valueByBundleName:defaultBundle language:language defaultValue:nil];
  }

• (NSString *)valueByBundleName:(NSString *)bundle language:(NSString *)language defaultValue:(NSString *)value{
  return [self valueByBundleName:bundle language:language defaultValue:value table:nil];
  }

• (NSString *)valueByBundleName:(NSString *)bundle language:(NSString *)language defaultValue:(NSString *)value table:(NSString *)table{
  if (!bundle) {
  return [[NSBundle mainBundle] localizedStringForKey:self value:value table:nil];
  }
  NSBundle *languageBundle = nil;
  if (!bundleDic[bundle]) {
  NSString *bundlePath = [[NSBundle mainBundle] pathForResource:bundle ofType:@"bundle"];
  languageBundle = [NSBundle bundleWithPath:[[NSBundle bundleWithPath:bundlePath] pathForResource:language ofType:@"lproj"]];
  bundleDic[bundle] = languageBundle;
  }else{
  languageBundle = bundleDic[bundle];
  }
  NSString *vv = [languageBundle localizedStringForKey:self value:value table:table];
  return [[NSBundle mainBundle] localizedStringForKey:self value:vv table:table];
  }
  @end