<div class="content" name="AddKey" uuid="0ebc0707-0fa4-4093-b9d3-e30302e8f1d9"><p>The AddKey method creates a node and adds it to the <a href="1243ba70-74ca-44f9-be0b-dfd6697010b4#gt_086b13f2-2715-4000-a16c-6acc3d59cc19" data-linktype="relative-path">metabase</a> as a subnode of an
existing node at the specified path.</p><dl>
<dd>
<div><pre> HRESULT AddKey(
   [in] METADATA_HANDLE hMDHandle,
   [unique, in, string] LPCWSTR pszMDPath
 );
</pre></div>
</dd></dl><p><b>hMDHandle: </b>An unsigned 32-bit integer value
containing an open metabase handle specifying the node in the metabase where
the new key is to be added.</p><p><b>pszMDPath: </b>A pointer to a Unicode string that
contains the new node&#39;s path, relative to the path of the <i>hMDHandle</i>
parameter.</p><p><b>Return Values: </b>A signed 32-bit value that
indicates return status. If the method returns a negative value, it failed. If
the 12-bit facility code (bits 16–27) is set to 0x007, the value contains a
Win32 error code in the lower 16 bits. Zero or positive values indicate
success, with the lower 16 bits in positive nonzero values containing warnings
or flags defined in the method implementation. For more information about Win32
error codes and <a href="../ms-dtyp/a9046ed2-bfb2-4d56-a719-2824afce59ac" data-linktype="relative-path">HRESULT</a>
values, see <a href="../ms-erref/1bc92ddf-b79e-413c-bbaa-99a5281a6c90" data-linktype="relative-path">[MS-ERREF]</a>.</p><dl>
<dd>
<table><thead>
  <tr>
   <th>
   <p>Return value/code</p>
   </th>
   <th>
   <p>Description</p>
   </th>
  </tr>
 </thead><tbody><tr>
  <td>0x00000000 S_OK</td>
  <td>The call was successful.</td>
 </tr><tr>
  <td>0x80070005 E_ACCESSDENIED</td>
  <td>General access denied error.</td>
 </tr><tr>
  <td>0x80070006 ERROR_INVALID_HANDLE</td>
  <td>The handle is invalid.</td>
 </tr><tr>
  <td>0x80070057 E_INVALIDARG</td>
  <td>One or more arguments are invalid.</td>
 </tr><tr>
  <td>0x800700B7 ERROR_ALREADY_EXISTS</td>
  <td>Cannot create a file because that file already exists.</td>
 </tr></tbody></table>
</dd></dl><p>The <a href="1243ba70-74ca-44f9-be0b-dfd6697010b4#gt_e127848e-c66d-427d-b3aa-9f904fa4ada7" data-linktype="relative-path">opnum</a>
field value for this method is 3.</p><p>When processing this call, the <a href="1243ba70-74ca-44f9-be0b-dfd6697010b4#gt_434b0234-e970-4e8c-bdfa-e16a30d96703" data-linktype="relative-path">server</a> MUST do the
following:</p><ul><li><p><span><span> 
</span></span>Check the handle parameter. This handle is valid if it is either
the master root handle or a handle returned from a previous <a href="a54be1d0-009a-493d-a53e-e2f7fbe87293" data-linktype="relative-path">OpenKey</a> call. If the
handle is invalid, return ERROR_INVALID_HANDLE error.</p>
</li><li><p><span><span> 
</span></span>The server SHOULD check whether the parent handle, <i>hMDHandle</i>,
was opened for write access. If not, return E_ACCESSDENIED<a id="Appendix_A_Target_4"></a><a aria-label="Product behavior note 4" href="88fd1df0-e63e-41ca-9bf3-bedcab57cd86#Appendix_A_4" data-linktype="relative-path">&lt;4&gt;</a>.</p>
</li><li><p><span><span> 
</span></span>Check whether the relative path has the right syntax and length.
If not, return an error.</p>
</li><li><p><span><span> 
</span></span>Check whether the relative path refers to an existing node. If
so, return ERROR_ALREADY_EXISTS.</p>
</li><li><p><span><span> 
</span></span>Add a new node to the tree that has the resultant path as a
combined path of the parent node specified by the <i>hMDHandle</i> parameter
and the relative path specified by the <i>pszMDPath</i> parameter. If any
intermediate nodes are required, the server creates these nodes.</p>
</li></ul></div>