通过套接字发送数据时的编码问题

Question

我试图将数据发送到UDP服务器，并且出现了一些问题。发送后我没有收到数据。然后我尝试了一个网络记录器。我可以看到当我使用NSUTF8Stringencoding它显示在网络日志上，但是当我使用NSASCIIEncoding时，它不会发送。

我真的很喜欢一些帮助。我正在使用CocaoAsyncUDPSocket。如果anynone可以帮助再次获得数据，那将非常酷。

这里是我的代码：

NSString *ipString = @"192.168.0.116:7777"; 
NSArray *splitArray = [ipString componentsSeparatedByString:@":"]; 

NSString *ip = [splitArray objectAtIndex:0]; 
NSString *port = [splitArray objectAtIndex:1]; 

NSArray *ipArray = [ip componentsSeparatedByString:@"."]; 
char ipNumber1 = [self chr:[[ipArray objectAtIndex:0] intValue]]; 
char ipNumber2 = [self chr:[[ipArray objectAtIndex:1] intValue]]; 
char ipNumber3 = [self chr:[[ipArray objectAtIndex:2] intValue]]; 
char ipNumber4 = [self chr:[[ipArray objectAtIndex:3] intValue]]; 

char portByte1 = [self chr:[port intValue] & 0xFF]; 
char portByte2 = [self chr:[port intValue] >> 8 & 0xFF]; 
NSString *packetString = [NSString stringWithFormat:@"SAMP%c%c%c%c%c%cp4150", ipNumber1, ipNumber2, ipNumber3, ipNumber4, portByte1, portByte2]; 

GCDAsyncUdpSocket *socket = [[GCDAsyncUdpSocket alloc] initWithDelegate:self delegateQueue:dispatch_get_main_queue()]; 
NSError *err = nil; 
NSData *data = [packetString dataUsingEncoding:NSASCIIStringEncoding]; 
[socket sendData:data toHost:ip port:[port intValue] withTimeout:-1 tag:1]; 
NSLog(@"%@", packetString); 

这一个永远不会被调用：

-(void)udpSocket:(GCDAsyncUdpSocket *)sock didReceiveData:(NSData *)data fromAddress:(NSData *)address withFilterContext:(id)filterContext; { 

    NSLog(@"Received data"); 
} 

下面是用C＃编写相同的功能http://wiki.sa-mp.com/wiki/Query_Mechanism/Csharp

Answer 1

NSString是Unicode字符序列，并且不能用作您在此处具有的任意字节序列的容器。

你最好先创建一个字节的缓冲区的消息，并直接将其转换成 NSData：

unsigned char buffer[20]; // Choose a size that is large enough for your messages 
memcpy(&buffer[0], "SAMP", 4); 
buffer[4] = [[ipArray objectAtIndex:0] intValue]; 
buffer[5] = [[ipArray objectAtIndex:1] intValue]; 
buffer[6] = [[ipArray objectAtIndex:2] intValue]; 
buffer[7] = [[ipArray objectAtIndex:3] intValue]; 
buffer[8] = [port intValue] & 0xFF; 
buffer[9] = [port intValue] >> 8 & 0xFF; 
memcpy(&buffer[10], "p4150", 5); 
int messageSize = 15; 
NSData *data = [NSData dataWithBytes:buffer length:messageSize];