关于十六进制 hex 转换成NSString 中文乱码问题

今天在cocoaChina上看到有人问到，以前记得在哪儿看到过解决方法，特此标记一下：

- (NSString *)stringFromHexString:(NSString *)hexString {  // eg. hexString = @"8c376b4c"
    
    char *myBuffer = (char *)malloc((int)[hexString length] / 2 + 1);
    bzero(myBuffer, [hexString length] / 2 + 1);
    for (int i = 0; i < [hexString length] - 1; i += 2) {
        unsigned int anInt;
        NSString * hexCharStr = [hexString substringWithRange:NSMakeRange(i, 2)];
        NSScanner * scanner = [[[NSScanner alloc] initWithString:hexCharStr] autorelease];
        [scanner scanHexInt:&anInt];
        myBuffer[i / 2] = (char)anInt;
    }
    NSString *unicodeString = [NSString stringWithCString:myBuffer encoding:NSUnicodeStringEncoding];
//    printf("%s\n", myBuffer);
    free(myBuffer);
    
    NSString *temp1 = [unicodeString stringByReplacingOccurrencesOfString:@"\\u" withString:@"\\U"];
    NSString *temp2 = [temp1 stringByReplacingOccurrencesOfString:@"\"" withString:@"\\\""];
    NSString *temp3 = [[@"\"" stringByAppendingString:temp2] stringByAppendingString:@"\""];
    NSData *tempData = [temp3 dataUsingEncoding:NSUTF8StringEncoding];
    NSString *temp4 = [NSPropertyListSerialization propertyListFromData:tempData
                                                           mutabilityOption:NSPropertyListImmutable
                                                                     format:NULL
                                                           errorDescription:NULL];
    NSString *string = [temp4 stringByReplacingOccurrencesOfString:@"\\r\\n" withString:@"\n"];
    
    NSLog(@"-------string----%@", string); //输出 谷歌
    return string;
}