C-C++ Code Example: Retrieving PROPID_Q_PATHNAME

 

Applies To: Windows 10, Windows 7, Windows 8, Windows 8.1, Windows Server 2008, Windows Server 2008 R2, Windows Server 2012, Windows Server 2012 R2, Windows Server Technical Preview, Windows Vista

This example provides an application-defined function that retrieves the PROPID_Q_PATHNAME property of an existing queue and returns the path name to the caller.

This function must retrieve information stored in the directory service to return the path name of an existing public queue.

To retrieve PROPID_Q_PATHNAME

1. Define the maximum number of queue properties to be specified and the queue property counter.

2. Define the MQQUEUEPROPS structure.

3. Specify PROPID_Q_PATHNAME.

4. Initialize the MQQUEUEPROPS structure.

5. Validate the input parameters provided by the caller.

6. Call MQGetQueueProperties to retrieve the path name of the queue. If the call fails the returned error code is returned to the caller.

7. Pass a pointer to the string containing the retrieved path name to the caller on return.

Note

After your application no longer needs the path name buffer, the caller must free the memory allocated for it using MQFreeMemory.

Code Example

The following code example can be run on all versions of Message Queuing.

HRESULT GetQueuePathnameProp(  
                             LPCWSTR wszQueueFormatName,   
                             LPWSTR *pwszValue  
                             )  
{  
  
  // Define the maximum number of queue properties and a property counter.  
  const int NUMBEROFPROPERTIES = 1;  
  DWORD cPropId=0;  
  
  // Define a queue property structure.  
  MQQUEUEPROPS   QueueProps;  
  QUEUEPROPID    aQueuePropId[NUMBEROFPROPERTIES];  
  MQPROPVARIANT  aQueuePropVar[NUMBEROFPROPERTIES];  
  HRESULT        aQueuePropStatus[NUMBEROFPROPERTIES];  
  HRESULT hr = MQ_OK;  
  
  // Specify the PROPID_Q_PATHNAME property.  
  aQueuePropId[cPropId] = PROPID_Q_PATHNAME;       // Property ID  
  aQueuePropVar[cPropId].vt = VT_NULL;            // Type indicator  
  cPropId++;  
  
  // Initialize the MQQUEUEPROPS structure.  
  QueueProps.cProp = cPropId;  
  QueueProps.aPropID = aQueuePropId;  
  QueueProps.aPropVar = aQueuePropVar;  
  QueueProps.aStatus = aQueuePropStatus;  
  
  // Validate the input string.  
  if (wszQueueFormatName == NULL)  
  {  
    return MQ_ERROR_INVALID_PARAMETER;  
  }  
  
  // Get the queue properties.  
  hr = MQGetQueueProperties(wszQueueFormatName, &QueueProps);  
  if (FAILED(hr))  
  {  
    return hr;  
  }  
  
  // Set the *pwszValue parameter to the pointer to the string containing  
  // the path name of the queue returned by MQGetQueueProperties.  
  *pwszValue = aQueuePropVar[0].pwszVal;  
  return hr;  
}