PROPID_M_EXTENSION (Windows CE 5.0)
This property provides a place to put additional application-defined information that is associated with the message.
- Type Indicator
VT_UI1 | VT_VECTOR - PROPVARIANT Field
caub - Property Values
Array of bytes
Remarks
The PROPID_M_EXTENSION property is typically used by applications that need to specify or read non-MSMQ message properties when working with foreign queues.
The application is responsible to understand the content of this property.
To send extension information, specify PROPID_M_EXTENSION in the MQMSGPROPS structure and call MQSendMessage.
To retrieve extension information, specify PROPID_M_EXTENSION and PROPID_M_EXTENSION_LEN in the MQMSGPROPS structure. Then call MQReceiveMessage and examine the returned values.
Before using the returned value of PROPID_M_EXTENSION, inspect the returned value of PROPID_M_EXTENSION_LEN to see if extension information was sent.
A returned value of 0 indicates that no information was sent by the sending application.
A nonzero returned value indicates the extension information was returned by PROPID_M_EXTENSION.
This property is not available when you use COM components.
Examples
The following examples show how PROPID_M_EXTENSION is specified in the MQMSGPROPS structure for sending and retrieving extension information.
To send extension information
aMsgPropId[i] = PROPID_M_EXTENSION; // Property ID
aMsgPropVar[i].vt = VT_UI1 | VT_VECTOR; // Type indicator
aMsgPropVar[i].caub.pElems = ExtensionInformation;
aMsgPropVar[i].caub.cElems = sizeof(ExtensionInformation);
i++;
To retrieve extension information
aMsgPropId[i] = PROPID_M_EXTENSION_LEN; // Property ID
aMsgPropVar[i].vt = VT_UI4; // Type indicator
i++;
aMsgPropId[i] = PROPID_M_EXTENSION; // Property ID
aMsgPropVar[i].vt = VT_UI1 | VT_VECTOR; // Type indicator
i++;
Requirements
OS Versions: Windows CE 2.0 and later. Versions prior to 2.12 require the MSMQ add-on pack.
Header: Mq.h.
See Also
MQReceiveMessage | PROPID_M_EXTENSION_LEN | MQMSGPROPS
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