C-C++ Code Example: Setting PROPID_Q_PRIV_LEVEL


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 sets the PROPID_Q_PRIV_LEVEL property of an existing queue based on a given privacy level provided by the caller.

Setting this property for an existing queue changes how the queue will handle new messages sent to the queue, however, setting this property has no effect on messages already in the queue.

A direct format name can be passed to this function only for a local private queue.

For information on how Message Queuing encrypts messages, see Message Encryption.


  1. Validate the input parameters provided by the caller.

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

  3. Define the MQQUEUEPROPS structure.


  5. Initialize the MQQUEUEPROPS structure.

  6. Call MQSetQueueProperties to set the privacy level of the queue. If the call fails the returned error code is returned to the caller.

Code Example

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

HRESULT SetQueuePrivlevelProp(  
                              LPCWSTR wszQueueFormatName,   
                              int iValue  
  // Validate the input string.  
  if (wszQueueFormatName == NULL)  
  // 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;  
  HRESULT        aQueuePropStatus[NUMBEROFPROPERTIES];  
  HRESULT hr = MQ_OK;  
  // Specify the PROPID_Q_PRIVACY_LEVEL property.  
  aQueuePropId[cPropId] = PROPID_Q_PRIVACY_LEVEL;  // Property ID  
  aQueuePropVar[cPropId].vt = VT_UI4;              // Type indicator  
  aQueuePropVar[cPropId].ulVal= iValue;            // Privacy level  
  // Initialize the MQQUEUEPROPS structure.  
  QueueProps.cProp = cPropId;  
  QueueProps.aPropID = aQueuePropId;  
  QueueProps.aPropVar = aQueuePropVar;  
  QueueProps.aStatus = aQueuePropStatus;  
  // Set the queue properties.  
  hr = MQSetQueueProperties(wszQueueFormatName, &QueueProps);  
  return hr;