<div class="content" name="Activity_Context_Property" uuid="c89181b4-a06f-4265-8860-0088df619382"><p>To indicate to the server that the client is running within
an <a href="482ab606-0b55-4821-8b6d-d453351406c5#gt_40358b87-f131-4ea9-8e87-51912d97d3cf" data-linktype="relative-path">activity</a>, the client
MUST include an activity context property as part of the client context in an
object activation request. </p><p>The <b>policyId</b> field of the <a href="../ms-dcom/6865a1c4-f094-486e-990a-436257db57e5" data-linktype="relative-path">PROPMARSHALHEADER</a>
instance (<a href="../ms-dcom/4a893f3d-bd29-48cd-9f43-d9777a4415b0" data-linktype="relative-path">[MS-DCOM]</a>
section 2.2.20.1) for the activity context property MUST be set to
guidActivityProperty, as specified in section <a href="738db53c-1600-432e-b288-63679b581471" data-linktype="relative-path">1.9</a>. The <b>CLSID</b>
field of the PROPMARSHALHEADER instance ([MS-DCOM] section 2.2.20.1) for the
activity context property MUST be set to GUID_NULL. The activity context
property MUST be marshaled using the <a href="../ms-dcom/88fdb261-7c9a-41ea-bfac-31583bdc65e6" data-linktype="relative-path">OBJREF_CUSTOM</a>
format ([MS-DCOM] section 2.2.18.6), and the <b>CLSID</b> field of the
OBJREF_CUSTOM instance MUST be set to CLSID_ActivityUnmarshal, as specified in
section 1.9.</p><p>The format of the OBJREF_CUSTOM.pObjectData buffer for
CLSID_ActivityUnmarshal MUST be specified as follows.</p><table>
 <tbody><tr>
  <th><p><br/>0</p></th>
  <th><p><br/>1</p></th>
  <th><p><br/>2</p></th>
  <th><p><br/>3</p></th>
  <th><p><br/>4</p></th>
  <th><p><br/>5</p></th>
  <th><p><br/>6</p></th>
  <th><p><br/>7</p></th>
  <th><p><br/>8</p></th>
  <th><p><br/>9</p></th>
  <th><p>1<br/>0</p></th>
  <th><p><br/>1</p></th>
  <th><p><br/>2</p></th>
  <th><p><br/>3</p></th>
  <th><p><br/>4</p></th>
  <th><p><br/>5</p></th>
  <th><p><br/>6</p></th>
  <th><p><br/>7</p></th>
  <th><p><br/>8</p></th>
  <th><p><br/>9</p></th>
  <th><p>2<br/>0</p></th>
  <th><p><br/>1</p></th>
  <th><p><br/>2</p></th>
  <th><p><br/>3</p></th>
  <th><p><br/>4</p></th>
  <th><p><br/>5</p></th>
  <th><p><br/>6</p></th>
  <th><p><br/>7</p></th>
  <th><p><br/>8</p></th>
  <th><p><br/>9</p></th>
  <th><p>3<br/>0</p></th>
  <th><p><br/>1</p></th>
 </tr>
 <tr>
  <td colspan="16">MaxVersion</td>
  <td colspan="16">MinVersion</td>
 </tr>
 <tr>
  <td colspan="32">ActivityID (16 bytes)</td>
 </tr>
 <tr>
  <td colspan="32">...</td>
 </tr>
 <tr>
  <td colspan="32">...</td>
 </tr>
 <tr>
  <td colspan="32">Timeout</td>
 </tr>
</tbody></table><p><b>MaxVersion (2 bytes): </b>The major version number
for this activity context property format. This field MUST be set to 0x0001.</p><p><b>MinVersion (2 bytes): </b>The minor version number
for this activity context property format. This field MUST be set to 0x0001.</p><p><b>ActivityID (16 bytes): </b>A <a href="482ab606-0b55-4821-8b6d-d453351406c5#gt_f49694cc-c350-462d-ab8e-816f0103c6c1" data-linktype="relative-path">GUID</a> that MUST specify the <a href="482ab606-0b55-4821-8b6d-d453351406c5#gt_4df8c10b-a8c7-456b-87b8-2999db34734a" data-linktype="relative-path">activity ID</a>.</p><p><b>Timeout (4 bytes): </b>An unsigned long that MUST
specify the activity time-out in milliseconds. A value of 0xFFFFFFFF MUST be
interpreted to specify an INFINITE time-out.</p></div>