PROPID_Q_LABEL

  • Article

Optional. This property specifies a description of the queue.

  • Type Indicator
    VT_LPWSTR
  • PROPVARIANT Field
    pwszVal
  • Property Value
    String (default is ""). The maximum length of the string is MQ_MAX_Q_LABEL_LEN (124 Unicode characters).

Remarks

The label of a queue is used to identify the queue.

For public queues, the label can be used as the search criteria for a query. By using the same label for several queues, the application can later run a query on the queue label and locate all the queues. A query can also be used to retrieve the label of a public queue.

To specify the label of a queue when creating a queue, specify PROPID_Q_LABEL in the MQQUEUEPROPS structure and call MQCreateQueue.

To change the label of a queue, specify PROPID_Q_LABEL in the MQQUEUEPROPS structure and call MQSetQueueProperties.

To retrieve the label of a queue, specify PROPID_Q_LABEL in the MQQUEUEPROPS structure and call MQGetQueueProperties and examine its returned value. When specifying PROPID_Q_LABEL, set the type indicator for PROPID_Q_LABEL to VT_NULL so that MSMQ will allocate the memory needed for the label. Later, the allocated memory must be freed using MQFreeMemory.

Examples

The following examples show how PROPID_Q_LABEL is specified in the MQQUEUEPROPS structure for setting and retrieving the label of a queue. Note that when retrieving the label, the type indicator is set to VT_NULL.

To set the label of a queue

LPWSTR wszQueueLabel = L"Test Queue";
aPropID[i] = PROPID_Q_LABEL;                // Property identifier
aVariant[i].vt = VT_LPWSTR;                 // Type indicator
aVariant[i].pwszVal = wszQueueLabel ;       // Label of queue

To retrieve the label of a queue

aPropID[i] = PROPID_Q_AUTHENTICATE;         // Property identifier
aVariant[i].vt = VT_NULL;                   // Type indicator
i++;

Requirements

Runs on Versions Defined in Include Link to
Windows CE OS 2.0 and later. Versions prior to 2.12 require the MSMQ add-on pack. Mq.h    

Note   This API is part of the complete Windows CE OS package as provided by Microsoft. The functionality of a particular platform is determined by the original equipment manufacturer (OEM) and some devices may not support this API.

See Also

MQCreateQueue, MQFreeMemory, MQGetQueueProperties, MQSetQueueProperties, MQQUEUEPROPS

 Last updated on Tuesday, July 13, 2004

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