自从发布了关于枚举多个设备的original question之后,我已经发现了多个枚举没有出现的原因;这些设备都具有相同的deviceID。有了这个发现,我想提出一个新的问题,满怀希望地引出一个关于.
编辑
新问题:
当所有设备使用相同的deviceID时,是否有唯一枚举以外的方法可用于为每个设备获取专用套接字?
场景和规则:
我正在Windows 7上开发一个应用程序,使用Microsoft和ANSI C编译器。应用程序设计要求它检测范围内的任何IrDA设备,使用套接字进行连接,并进行通信。通信将通过多个IrDA连接器(每个设备一根)与多个设备通信,每个设备通过USB连接到PC上。注意:避免使用虚拟COM端口。
的目标:将每个设备连接到自己的套接字上,在它和应用软件之间提供一个专用的通信通道。
下面是示例和源代码(用于枚举IrDA设备)。
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演示1:总体场景:

演示2:来自设备管理器:

演示3:每个“找到的”IrDA设备的属性:

这里是枚举两个或多个唯一的IrDA设备的代码:(测试和工作良好)
//Adapted from: http://msdn.microsoft.com/en-us/library/windows/desktop/ms738544(v=vs.85).aspx
#include <winsock2.h>
#include <ws2tcpip.h>
#include <af_irda.h>
#include <stdio.h>
#include <windows.h>
// link with Ws2_32.lib
char* iGetLastErrorText(DWORD nErrorCode);
int __cdecl main(void)
{
//-----------------------------------------
// Declare and initialize variables
WSADATA wsaData;
int iResult;
int i, tries = 0;
DWORD dwError;
SOCKET Sock = INVALID_SOCKET;
#define DEVICE_LIST_LEN 10
SOCKADDR_IRDA DestSockAddr = { AF_IRDA, 0, 0, 0, 0, "SampleIrDAService" };
unsigned char DevListBuff[sizeof (DEVICELIST) -
sizeof (IRDA_DEVICE_INFO) +
(sizeof (IRDA_DEVICE_INFO) * DEVICE_LIST_LEN)];
int DevListLen = sizeof (DevListBuff);
PDEVICELIST pDevList;
pDevList = (PDEVICELIST) & DevListBuff;
// Initialize Winsock
iResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
if (iResult != 0) {
printf("WSAStartup failed: %d\n", iResult);
return 1;
}
Sock = socket(AF_IRDA, SOCK_STREAM, 0);
if (Sock == INVALID_SOCKET) {
dwError = WSAGetLastError();
printf
("socket failed trying to create an AF_IRDA socket with error %d\n",
dwError);
if (dwError == WSAEAFNOSUPPORT) {
printf("Check that the local computer has an infrared device\n");
printf
("and a device driver is installed for the infrared device\n");
}
WSACleanup();
return 1;
}
pDevList->numDevice = 0;
while((pDevList->numDevice < 2)&&( tries++ < 3 ))
{
// Sock is not in connected state
iResult = getsockopt(Sock, SOL_IRLMP, IRLMP_ENUMDEVICES,
(char *) pDevList, &DevListLen);
if (iResult == SOCKET_ERROR) {
printf("getsockopt failed with error %d - %s\n", WSAGetLastError(), iGetLastErrorText(WSAGetLastError()));
iResult = closesocket(Sock);
if(iResult == SOCKET_ERROR)
{
printf("closesocket failed with error %d - %s\n", WSAGetLastError(), iGetLastErrorText(WSAGetLastError()));
WSACleanup();
getchar();
return 1;
}
WSACleanup();
getchar();
return 1;
}
if (pDevList->numDevice == 0) {
// no devices discovered or cached
// not a bad idea to run a couple of times
printf("No IRDA devices were discovered or cached\n");
} else {
// one per discovered device
printf("pDevList->numDevice = %d\n", pDevList->numDevice);
for (i = 0; i < (int) pDevList->numDevice; i++) {
printf( "irdaCharSet: %d\nHints1: %d\nHints2: %d\nDeviceID: %x\nDeviceName: %s\n\n",
pDevList->Device[i].irdaCharSet,
pDevList->Device[i].irdaDeviceHints1,
pDevList->Device[i].irdaDeviceHints2,
pDevList->Device[i].irdaDeviceID,
pDevList->Device[i].irdaDeviceName);
// typedef struct _IRDA_DEVICE_INFO
// {
// u_char irdaDeviceID[4];
// char irdaDeviceName[22];
// u_char irdaDeviceHints1;
// u_char irdaDeviceHints2;
// u_char irdaCharSet;
// } _IRDA_DEVICE_INFO;
// pDevList->Device[i]. see _IRDA_DEVICE_INFO for fields
// display the device names and let the user select one
}
}
}
// assume the user selected the first device [0]
memcpy(&DestSockAddr.irdaDeviceID[0], &pDevList->Device[0].irdaDeviceID[0],4);
iResult = connect(Sock, (const struct sockaddr *) &DestSockAddr, sizeof (SOCKADDR_IRDA));
if (iResult == SOCKET_ERROR)
{
if (iResult == SOCKET_ERROR) {
printf("connect failed with error %d - %s\n", WSAGetLastError(), iGetLastErrorText(WSAGetLastError()));
iResult = closesocket(Sock);
if(iResult == SOCKET_ERROR)
{
printf("closesocket failed with error %d - %s\n", WSAGetLastError(), iGetLastErrorText(WSAGetLastError()));
WSACleanup();
getchar();
return 1;
}
WSACleanup();
getchar();
return 1;
}
}
else
{
printf("connect to first IRDA device was successful\n");
}
getchar();
WSACleanup();
return 0;
}
char* iGetLastErrorText(DWORD nErrorCode)
{
char* msg;
// Ask Windows to prepare a standard message for a GetLastError() code:
FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, nErrorCode, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPSTR)&msg, 0, NULL);
// Return the message
if (!msg)
return("Unknown error");
else
return(msg);
}发布于 2014-02-05 21:06:56
结束了这个老问题的循环:简短的回答是不,没有其他的方法。
IrDA套接字是创建的,在我的例子中,在Windows7中,是基于对任何和所有IrDA信号在活动和范围内的询问而枚举的。枚举过程为存储它找到的每个唯一的设备ID (特别是IrDA Dev id)的数据。如果它看到3个唯一的设备it,则可以存储每个it的数据,并使连接可用以完成连接。随后,对于每个连接,可以与每个设备进行单独的对话。但是,如果相同的三个设备处于活动状态,并且在范围内,具有相同的设备ID ,则Windows将只存储与该一个ID相对应的数据,并且只能进行一个连接。
https://stackoverflow.com/questions/17928852
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