创建与服务器的输入输出流

 1 - (void)GetStreamsToHost:(NSString *)aHost Port:(NSInteger)aPort InputStream:(NSInputStream **)aInputStream OutputStream:(NSOutputStream **)aOutputStream
 2 {
 3     CFReadStreamRef bRead;
 4     CFWriteStreamRef bWrite;
 5     
 6     bRead = NULL;
 7     bWrite = NULL;
 8     
 9     CFStreamCreatePairWithSocketToHost(NULL, (CFStringRef)aHost, aPort, 
10                                        ((aInputStream != nil) ? &bRead : NULL), 
11                                        ((aOutputStream != nil) ? &bWrite : NULL));
12     
13     if (aInputStream != NULL) {
14         *aInputStream = [NSMakeCollectable(bRead) autorelease];
15     }
16     if (aOutputStream!= NULL) {
17         *aOutputStream = [NSMakeCollectable(bWrite) autorelease];
18     }
19 }