VC下如何获得可使用的COM口?

[mandysss]

如何获得目前可使用的COM口.除了电脑自带的COM1外,比如通过USB连接的手机,虚拟成的COM口.怎么得到这些?

[fengrx]

看下这个：
点击：
CSerialPort v1.03 - Serial Port Wrapper

[huohuo777777]

谢谢楼上的

[z888c]

HANDLE CreateFile(
LPCTSTR lpFileName,

The following reserved device names cannot be used as the name of a file: CON, PRN, AUX, NUL, COM1, COM2, COM3, COM4, COM5, COM6, COM7, COM8, COM9, LPT1, LPT2, LPT3, LPT4, LPT5, LPT6, LPT7, LPT8, and LPT9.

[Conry]

HKEY_LOCAL_MACHINE\\HARDWARE\\DEVICEMAP\\SERIALCOMM\\

[用户 昵称]

就是读注册表。

[一条晚起的虫]

//可以通过遍历注册表项
//HKEY_LOCAL_MACHINE\\HARDWARE\\DEVICEMAP\\SERIALCOMM\\

	HKEY hKey;  
	int rtn;

	m_cmbComm.ResetContent();
	rtn = RegOpenKeyEx( HKEY_LOCAL_MACHINE, "Hardware\\DeviceMap\\SerialComm",   
	  NULL, KEY_READ, &hKey);
	if( rtn == ERROR_SUCCESS)   //   打开串口注册表   
	{   
		int   i=0;   
		char   portName[256],commName[256];   
		DWORD   dwLong,dwSize;   
		while(1)   
		{   
			dwSize =   sizeof(portName);   
			dwLong   =   dwSize;
			rtn = RegEnumValue( hKey, i, portName, &dwLong,   
			  NULL, NULL, (PUCHAR)commName, &dwSize );
			if( rtn == ERROR_NO_MORE_ITEMS )   //   枚举串口   
				break;   //   commName就是串口名字   
			i++;   
		}   
		RegCloseKey(hKey);   
	}  

[swb986]

吼吼，不错啊

[hawking81]

可以打开文件（就是串口了） 看返回值正常就可用

[sanguomi]

读注册表就可以了，

[killbug2004]

我的程序就是用5楼的代码，遍历注册表

bool SerialEnum::query()
{
	HKEY hKey = NULL;
	
	// try to open target registry key
	if (ERROR_SUCCESS != RegOpenKeyEx( HKEY_LOCAL_MACHINE,
		TEXT("HARDWARE\\DEVICEMAP\\SERIALCOMM"),
		0,
		KEY_READ,
		&hKey))
	{
		return false;
	}

	bool     bResult = false;
	TCHAR    achClass[MAX_PATH] = TEXT("");		// buffer for class name 
	DWORD    cchClassName = MAX_PATH;			// size of class string 
	DWORD    cSubKeys=0;						// number of subkeys 
	DWORD    cbMaxSubKey;						// longest subkey size 
	DWORD    cchMaxClass;						// longest class string 
	DWORD    cValues;							// number of values for key 
	DWORD    cchMaxValue;						// longest value name 
	DWORD    cbMaxValueData;					// longest value data 
	DWORD    cbSecurityDescriptor;				// size of security descriptor 
	FILETIME ftLastWriteTime;					// last write time 
	
	DWORD    DataType;							//key data type
	unsigned char     KeyData[MAX_VALUE_DATA];	//key data buffer
	DWORD    DataSize = MAX_VALUE_DATA;			//key data size
	TCHAR	achValue[MAX_VALUE_NAME]; 
	DWORD	cchValue = MAX_VALUE_NAME; 
	char	tempstr[8];

	LONG retCode = 0;
	
	// Get the class name and the value count. 
	retCode = RegQueryInfoKey(
		hKey,                    // key handle 
		achClass,                // buffer for class name 
		&cchClassName,           // size of class string 
		NULL,                    // reserved 
		&cSubKeys,               // number of subkeys 
		&cbMaxSubKey,            // longest subkey size 
		&cchMaxClass,            // longest class string 
		&cValues,                // number of values for this key 
		&cchMaxValue,            // longest value name 
		&cbMaxValueData,         // longest value data 
		&cbSecurityDescriptor,   // security descriptor 
		&ftLastWriteTime);       // last write time 
	if (retCode != ERROR_SUCCESS)
	{
		bResult = false;
		goto _query_end;
	}

	// Enumerate the key values. 
	if (cValues == 0)
	{
		bResult = false;
		goto _query_end;
	}
	
	for (int i=0; i<cValues; i++) 
	{
		cchValue = MAX_VALUE_NAME; 
		achValue[0] = '\0'; 
		DataType=0;
		DataSize = MAX_VALUE_DATA;
		KeyData[0]='\0';
		
		retCode = RegEnumValue(
			hKey, i,
			achValue, 
			&cchValue, 
			NULL, 
			&DataType,
			KeyData,
			&DataSize);
		
		if (retCode == ERROR_SUCCESS ) 
		{
			if (strstr(achValue,"USBSER") != NULL)
			{
				int k, j;
				for (k=0,j=0; k<(int)DataSize; k++)
				{
					if ((KeyData[k]>'0' || KeyData[k]=='0') && (KeyData[k]<'9' || KeyData[k]=='9'))
					{
						tempstr[j] = KeyData[k];
						j++;
					}
				}
				tempstr[j]='\0';

				m_arrItem[m_nCount] = atoi(tempstr);
				m_nCount++;
			}
		}
	}
	bResult = (m_nCount > 0);

_query_end:
	RegCloseKey(hKey);
	return bResult;
}

[hfcarrey]

哈哈,最简单就是逐个打开试试

[fanlibing1984]

看不懂，深奥

[codelast.com]

我就是直接读注册表的。逐一打开进行测试的方法有个不可避免的问题：当前串口正在使用中的时候，就无法打开了

[zaodt]

注册表也不见得好在哪里；


一些 USB 转串口的，就会出现乱七八糟的东西！

[tcp8587]

不建议直接读注册表。还是逐一打开试试，代码如下：
CString strCom;
int nCom = 0;
int count = 0;
HANDLE hCom;
do {
nCom++;
strCom.Format("COM%d", nCom);
hCom = CreateFile(strCom, GENERIC_READ | GENERIC_WRITE, 0, NULL,
OPEN_EXISTING, FILE_FLAG_OVERLAPPED, 0);
m_ctrlPort.AddString( strCom );

GetDlgItem(IDC_CLOSEPORT)->EnableWindow();

if(INVALID_HANDLE_VALUE == hCom )
{
DWORD error=::GetLastError();//取得错误信息


break;
}
count++;
} while(1);

[fly2106]

///////////////////////////////////////////////////////////////////////////////////////读注册表
void CMyDlg::ShowComm()
{
long lReg;
HKEY hKey;
DWORD MaxValueLength;
DWORD dwValueNumber;

lReg=RegOpenKeyExA(HKEY_LOCAL_MACHINE, "HARDWARE\\DEVICEMAP\\SERIALCOMM", 0, KEY_QUERY_VALUE, &hKey);
if(lReg!=ERROR_SUCCESS)
{
AfxMessageBox(_T("Open Registry Error!\n"));
return;
}

lReg=RegQueryInfoKeyA(hKey,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
&dwValueNumber, //返回和hKey关联的值
&MaxValueLength,
NULL,
NULL,
NULL);
if(lReg!=ERROR_SUCCESS) //没有成功
{
AfxMessageBox(_T("Getting Info Error!\n"));
return;
}

LPSTR pValueName,pCOMNumber;
DWORD cchValueName,dwValueSize=6;

for(DWORD i=0;i < dwValueNumber;i++)
{
cchValueName=MaxValueLength+1;
dwValueSize=6;
pValueName=(LPSTR)VirtualAlloc(NULL,cchValueName,MEM_COMMIT,PAGE_READWRITE);
lReg=RegEnumValueA(hKey,
i,
pValueName,
&cchValueName,
NULL,
NULL,
NULL,
NULL);

if((lReg!=ERROR_SUCCESS)&&(lReg!=ERROR_NO_MORE_ITEMS))
{
AfxMessageBox(_T("Enum Registry Error or No More Items!\n"));
continue;
}

pCOMNumber=(LPSTR)VirtualAlloc(NULL,6,MEM_COMMIT,PAGE_READWRITE);
lReg=RegQueryValueExA(hKey,
pValueName,
NULL,
NULL,
(LPBYTE)pCOMNumber,
&dwValueSize);

if(lReg!=ERROR_SUCCESS)
{
AfxMessageBox(_T("Can not get the name of the port"));
continue;
}

CString strCommList(pCOMNumber);

BOOL m_bInsert=0;

if(((CComboBox*)GetDlgItem(IDC_COM_PORT))->GetCount()==0)
{
((CComboBox*)GetDlgItem(IDC_COM_PORT))->AddString(strCommList);
}
else
{
CString strTemp=strCommList;
strCommList.TrimLeft("COM");
for(int icurrent=0;icurrent<((CComboBox*)GetDlgItem(IDC_COM_PORT))->GetCount();icurrent++)
{
CString strCurrent;
((CComboBox*)GetDlgItem(IDC_COM_PORT))->GetLBText(icurrent,strCurrent);
strCurrent.TrimLeft("COM");
if(_ttol(strCurrent)>_ttol(strCommList))
{
((CComboBox*)GetDlgItem(IDC_COM_PORT))->InsertString(icurrent,strTemp);
m_bInsert = 1;
break;
}
}
if(!m_bInsert)
((CComboBox*)GetDlgItem(IDC_COM_PORT))->InsertString(icurrent,strTemp);
}

VirtualFree(pValueName,0,MEM_RELEASE);
VirtualFree(pCOMNumber,0,MEM_RELEASE);
}
}