IWMSPlaylistParser.ReadPlaylistFromDirectory (C#)

The ReadPlaylistFromDirectory method retrieves a playlist from an IWMSDirectoryIWMSDirectory Object (C#).

void IWMSPlaylistParser.ReadPlaylistFromDirectory(
  IWMSDirectory pDirectory,
  string pszwFilePattern,
  IXMLDOMDocument pPlaylist,
  IWMSPlaylistParserCallback pCallback,
  ulong qwContext
);

Arguments

	IWMSDirectory object containing the directory to read.
	string containing the file pattern to read.
	IXMLDOMDocumentIXMLDOMDocument Object (C#) in which to store the interpreted playlist that can be read by the server.
	IWMSPlaylistParserCallbackIWMSPlaylistParserCallback Object (C#) that is used by the plug-in to report the result of the ReadPlaylistFromDirectory method call back to the server.
	ulong containing a value defined by the server to identify which call to ReadPlaylistFromDirectory the plug-in is responding to when it calls IWMSPlaylistParserCallback.OnReadPlaylist. You must pass this value back unaltered when you call OnReadPlaylist.

Return Value

This method does not return a value. To report an error, the plug-in can throw a COMException object to the server. If the plug-in uses the IWMSEventLogIWMSEventLog Object (C#) to log error information, it is recommended that it throw NS_E_PLUGIN_ERROR_REPORTED (0xC00D157D). Typically, the server attempts to make plug-in error information available to the server object model, the Windows Event Viewer, and the troubleshooting list in the details pane of the Windows Media Services MMC. However, if the plug-in uses the IWMSEventLog object to send custom error information to the Windows Event Viewer, throwing NS_E_PLUGIN_ERROR_REPORTED stops the server from also logging to the event viewer. For more information about plug-in error information, see Identifying Plug-in Errors.

Remarks

The ReadPlaylistFromDirectory method interprets the playlist contained in a directory and populates the IXMLDOMDocument object. This method is implemented by the plug-in and called by the server.

In order to register a custom directory playlist parser plug-in you must specify a value of "{7408CEB0-3A5A-41b6-A5EC-9A4E811C9673}" for the "Input Format" property in the plug-in's registry settings. The following example shows how to register a directory playlist parser plug-in.

public const string strClassId = "E2D2CA7B-0B32-460f-95B3-11BD535C709B";
public const string strPlgName = "CSharp Playlist Parser Plugin";
public const string strSubKey1 = "SOFTWARE\\Microsoft\\Windows Media\\Server\\RegisteredPlugins\\Playlist Parser\\{" + strClassId + "}";
public const string strSubKey2 = "CLSID\\{" + strClassId + "}\\Properties";

[ComRegisterFunctionAttribute]
public static void RegisterFunction(Type t)
{
    try
    {
        RegistryKey regHKLM = Registry.LocalMachine;
        regHKLM = regHKLM.CreateSubKey(strSubKey1);
        regHKLM.SetValue(null, strPlgName);

        RegistryKey regHKCR = Registry.ClassesRoot;
        regHKCR = regHKCR.CreateSubKey(strSubKey2);
        regHKCR.SetValue("Name", strPlgName);
        regHKCR.SetValue("Author", "Plugin Author");
        regHKCR.SetValue("CopyRight", "Copyright (c).");
        regHKCR.SetValue("URL Suffix", ".dj");
        regHKCR.SetValue("Description", "This plugin parses .dj files.");
        regHKCR.SetValue("Input Format", "{7408CEB0-3A5A-41b6-A5EC-9A4E811C9673}");
    }
    catch
    {
        // TODO: Handle exceptions.
    }
}

Example

void IWMSPlaylistParser.ReadPlaylistFromDirectory(
    IWMSDirectory pDirectory,
    string pszwFilePattern,
    IXMLDOMDocument pPlaylist,
    IWMSPlaylistParserCallback pCallback,
    ulong qwContext)
{
    WMSDirectoryEntryInfo EntryInfo;
    IXMLDOMNode pNode;
    IXMLDOMElement pSMIL;
    IXMLDOMElement pElement;
    int i = 0;

    try
    {
        pNode = pPlaylist.createNode(
                   tagDOMNodeType.NODE_PROCESSING_INSTRUCTION, "wsx", "");
        pPlaylist.appendChild(pNode);
        pNode.text = "version='1.0'";

        pSMIL = pPlaylist.createElement("smil");
        pPlaylist.appendChild(pSMIL);

        pDirectory.GetChildInfo(Convert.ToUInt32(i), out EntryInfo);
        while( !EntryInfo.pstrName.Equals("") )
        {
            if( (Convert.ToInt32(EntryInfo.dwFlags) &
   (int)WMS_DIRECTORY_ENTRY_FLAGS.WMS_DIRECTORY_ENTRY_IS_DIRECTORY) == 0 )
            {
                pElement = pPlaylist.createElement("media");
                pElement.setAttribute("src", EntryInfo.pstrName);
                pSMIL.appendChild(pElement);
            }

            i++;
            pDirectory.GetChildInfo(Convert.ToUInt32(i), out EntryInfo);
        }

        pCallback.OnReadPlaylist(S_OK, qwContext);
    }
    catch
    {
        pCallback.OnReadPlaylist(E_FAIL, qwContext);
    }
}

Requirements

Reference: Add a reference to Microsoft.WindowsMediaServices.

Namespace: Microsoft.WindowsMediaServices.Interop.

Assembly: Microsoft.WindowsMediaServices.dll.

Library: WMSServerTypeLib.dll.

Platform: Windows Server 2003, Enterprise Edition; Windows Server 2003, Datacenter Edition; Windows Server 2008.

See Also

Concepts

IWMSPlaylistParser Object (C#)