如何将NSNrray的NSNr转换为NSData

时间:2011-10-13 20:01:33

标签: objective-c ios titanium nsdata titanium-modules

我是Objective C的新手,正在为发送UDP数据包的Titanium框架修改iOS模块。该模块当前允许您传入要发送的文本字符串,并将其转换为字节并通过UDP将其发送到目标IP和端口。这很好用,这是代码:

https://github.com/chrisfjones/titanium_module_udp/blob/master/UDPSocketProxy.m

我想要做的是将一个字节数组传递给send函数而不是字符串,并让它发送它。这是Titanium代码:

var udp = require('chrisfjones.titanium_module_udp');
var socket = udp.createUDP();
var bytes = [ 100, 15, 132, 53, 14, 246, 0, 0, 0, 0, 196, 209, 1, 1, 0, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 255, 16, 0, 45, 120, 0, 0, 0, 0, 158, 4, 111, 30, 179, 41 ];
socket.send(bytes, "1.2.3.4", 6100);

到目前为止,这是新的发送功能:

- (void) sendBytes: (NSArray*) args {

    NSArray *msg       = (NSArray*)[args objectAtIndex: 0];

    NSString *host      = [TiUtils stringValue:[args objectAtIndex: 1]];

    NSInteger port      = [TiUtils intValue:   [args objectAtIndex: 2]];


NSLog(@"%@ send bytes: %@ to %@:%i", self, msg, host, port);


struct sockaddr_in destinationAddress;

    socklen_t sockaddr_destaddr_len = sizeof(destinationAddress);



    memset(&destinationAddress, 0, sockaddr_destaddr_len);

    destinationAddress.sin_len = (__uint8_t) sockaddr_destaddr_len;

    destinationAddress.sin_family = AF_INET;

    destinationAddress.sin_port = htons(port);

    destinationAddress.sin_addr.s_addr = inet_addr([host cStringUsingEncoding: NSUTF8StringEncoding]);



    NSData *destinationAddressData = [NSData dataWithBytes:&destinationAddress length:sizeof(destinationAddress)];



    NSData *data = [NSKeyedArchiver archivedDataWithRootObject:msg];



    CFSocketError socket_error = CFSocketSendData(_socket, (CFDataRef) destinationAddressData, (CFDataRef) data, 10);

    if (socket_error) {

        NSLog(@"socket error: %li", socket_error);

    } else {

        NSLog(@"sent bytes: '%@' to %@:%i", msg, host, port);

    }

}

你会注意到它传入NSArray。这是因为Titanium将我创建的javascript数组转换为NSNumber对象的NSArray。我读到这是非常低效的,但是它内置于Titanium框架中,所以我没有看到它的方法,所以我希望得到一个答案,如何使它工作与这传入,而不是如何讲述如何效率低下。

当我调用新的send方法时,而不是发送我传入的大约50个字节,我可以在wireshark中看到它实际上传递超过1000个字节。我假设问题在于此行的转换:

NSData *data = [NSKeyedArchiver archivedDataWithRootObject:msg];

有人可以请教如何发送我传入的字节数组吗?谢谢!

2 个答案:

答案 0 :(得分:3)

是的,在这种情况下你不想使用归档器,因为你只是试图将一组字节变成NSData的块。根据您是传入NSNumber数组还是NSString数组,您基本上需要遍历数组的内容并将数据附加到NSMutableData

假设它是NSNumber的数组,那么这样的东西应该有用:

NSMutableData *data = [[NSMutableData alloc] initWithCapacity: [msg count]];
for( NSNumber *number in msg) {
    char byte = [number charValue];
    [data appendBytes: &byte length: 1];
}
// .... code that uses data ...
[data release];

如果数字是字符串形式的数字值,您可能希望使用-(int)intValue NSString方法提取数据,然后将其添加到数据中,基本上改变了上述内容到:

NSMutableData *data = [[NSMutableData alloc] initWithCapacity: [msg count]];
for( NSString *string in msg) {
    char byte = (char)[string intValue];
    [data appendBytes: &byte length: 1];
}
// .... code that uses data ...
[data release];

而且,如果你试图填充字符串中的字符,那么你需要使用[string characterAtIndex: 0]来抓取字符,并补偿你将收到unichar的事实一个char

答案 1 :(得分:0)

- (NSData *)byteArray2Data:(NSArray *)array {
    NSMutableData *data = [NSMutableData data];
    [array enumerateObjectsUsingBlock:^(NSNumber* number, NSUInteger index, BOOL* stop) {
        uint8_t tmp = number.unsignedCharValue;
        [data appendBytes:(void *)(&tmp)length:1];
    }];

    return data;
}

- (NSArray *)byteData2Array:(NSData *)data {
    NSMutableArray *array = [[NSMutableArray alloc] init];
    [data enumerateByteRangesUsingBlock:^(const void *bytes, NSRange byteRange, BOOL *stop) {
        unsigned char *dataBytes = (unsigned char*)bytes;
        for (NSInteger i = 0; i < byteRange.length; i++) {
            [array addObject:[NSNumber numberWithInt:(dataBytes[i]) & 0xff]];
        }
    }];

    return array;
}