使用正则匹配去除所有字符串
+ (NSString *)deleteChineseStringWithString:(NSString *)string {
    //    for (int i=0; i < string.length; i++) {  
    //        int utfCode = 0;
    //        void *buffer = &utfCode;
    //        NSRange range = NSMakeRange(i, 1);
    //        BOOL b = [string getBytes:buffer maxLength:2 usedLength:NULL encoding:NSUTF16LittleEndianStringEncoding options:NSStringEncodingConversionExternalRepresentation range:range remainingRange:NULL];
    //        if (b && (utfCode >= 0x4e00 && utfCode <= 0x9fa5)) {
    //            string = [string stringByReplacingCharactersInRange:range withString:@""];
    //        }
    //    }
    //    return string;
    
    // 创建匹配所有中文的正则表达式模式
    NSString *pattern = @"[\\p{Han}]+";
    // 使用正则表达式模式进行匹配
    NSError *error = nil;
    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:pattern options:0 error:&error];
    if (error) {
        NSLog(@"正则表达式错误: %@", error);
    }
    // 执行匹配并替换为空字符串，得到去除中文后的结果
    NSString *result = [regex stringByReplacingMatchesInString:string options:0 range:NSMakeRange(0, string.length) withTemplate:@""];
    // 输出结果
    NSLog(@"结果: %@", result); // 输出 "Hello word"
    return result;
    
}

截取字符串中的所有汉字

- (NSString *)getSimpleChineseWithString:(NSString *)string
{
    NSMutableArray *array = [NSMutableArray array];
    for (int i = 0; i < string.length; i++) {
        int a = [string characterAtIndex:i];
        if (a < 0x9fff && a > 0x4e00) {
            [array addObject:[string substringWithRange:NSMakeRange(i, 1)]];
        }
    }
    return [array componentsJoinedByString:@""];
}

判断是否有中文

-(BOOL)hasChinese {
    for(int i=0; i< [self length];i++){
        int a = [self characterAtIndex:i];
        if( a > 0x4e00 && a < 0x9fff)
        {
            return YES;
        }
    }
    return NO;
  
    //有中文的链接处理
   // str1 = [str stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
}