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Inserting Playlist Entries

  • Articolo

The following examples illustrate how to create a playlist and add multiple elements and attributes to it. You must create a new IXMLDOMElement object for every new element added. Note that the server adds attributes to the playlist object in the reverse of the order in which they appear in the code.

Visual Basic .NET Example

Imports Microsoft.WindowsMediaServices.Interop
Imports interop_msxml

Private Sub InsertEntry()

  ' Declare variables.
  Dim Server As WMSServer
  Dim Playlist As IXMLDOMDocument
  Dim ElementSmil As IXMLDOMElement
  Dim ElementMedia As IXMLDOMElement
  Dim ProcInst As IXMLDOMNode
  Dim Root As IXMLDOMNode
  Dim Node As IXMLDOMNode

  Try
    ' Create new WMSServer and IWMSPlaylist objects.
    Server = New WMSServer()
    Playlist = Server.CreatePlaylist

    ' Create the processing instruction node.
    ProcInst = Playlist.createNode( _
                       DOMNodeType.NODE_PROCESSING_INSTRUCTION, _
                       "wsx", _
                       "")

    ' Add the processing instruction to the file structure.
    Playlist.appendChild(ProcInst)
    ProcInst.text = "version = '1.0'"

    ' Create and add the root node of the playlist.
    ElementSmil = Playlist.createElement("smil")
    Root = Playlist.appendChild(ElementSmil)

    ' Create a media element for the playlist and add a 
    ' src attribute to it.
    ElementMedia = Playlist.createElement("media")
    ElementMedia.setAttribute("src", "c:\wmpub\wmroot\ad1.wmv")
    Node = Root.appendChild(ElementMedia)

    ' Create another media element and add multiple attributes to it.
    ' The server adds attributes to an element in the reverse of the
    ' order in which they appear in the code.
    ElementMedia = Playlist.createElement("media")
    ElementMedia.setAttribute("dur", "+.5min")
    ElementMedia.setAttribute("clipBegin", "0:00")
    ElementMedia.setAttribute("src", "c:\wmpub\wmroot\movie.wmv")
    Node = Root.appendChild(ElementMedia)

    ' Create another media element and add a src attribute to it.
    ElementMedia = Playlist.createElement("media")
    ElementMedia.setAttribute("src", "c:\wmpub\wmroot\ad2.wmv")
    Node = Root.appendChild(ElementMedia)

    ' Save the playlist.
    Playlist.save("c:\wmpub\wmroot\playlist.wsx")

  Catch Err As Exception
    ' TODO: Exception handler goes here.

  Finally
    ' TODO: Clean-up code goes here.

  End Try

End Sub

C# Example

using Microsoft.WindowsMediaServices.Interop;
using interop_msxml;

try
{
  // Declare the playlist, element, and node variables.
  IXMLDOMDocument playlist;
  IXMLDOMElement element_smil, element_media;
  IXMLDOMNode proc_inst, root, node;
    
  // Create new server and playlist objects.
  WMSServer server = new WMSServerClass();
  playlist = (IXMLDOMDocument)server.CreatePlaylist();
    
  // Create the processing instruction node.
  proc_inst = playlist.createNode(DOMNodeType.NODE_PROCESSING_INSTRUCTION,
                                  "wsx", "");
   
  // Add the processing instruction to the file structure.
  playlist.appendChild(proc_inst);
  proc_inst.text = "version = 1.0";
    
  // Create and add the root node of the playlist.
  element_smil = playlist.createElement("smil");
  root = playlist.appendChild(element_smil);
    
  // Create a media element and assign a src attribute.
  element_media = playlist.createElement("media");
  element_media.setAttribute("src", "c:\\wmpub\\wmroot\\ad1.wmv");

  node = root.appendChild(element_media);
    
  // Create another media element and add multiple attributes to
  // it. The server adds attributes to an element in the reverse
  // of the order in which they appear in the code.
  element_media = playlist.createElement("media");
  element_media.setAttribute("dur", "+.5min");
  element_media.setAttribute("clipBegin", "0:00");
  element_media.setAttribute("src", "c:\\wmpub\\wmroot\\movie.wmv");
  node = root.appendChild(element_media);
    
  // Create another media element and assign a src attribute.
  element_media = playlist.createElement("media");
  element_media.setAttribute("src", "c:\\wmpub\\wmroot\\ad2.wmv");
  node = root.appendChild(element_media);
    
  // Save the playlist.
  playlist.save("c:\\wmpub\\wmroot\\playlist.wsx");
}

catch (Exception)
{
  // TODO: Exception handler goes here.
}

finally
{
  // TODO: Clean-up code goes here.
}

C++ Example

// Include header files.
#include <windows.h>
#include <atlbase.h>    // Includes CComBSTR and CComVariant.
#include "wmsserver.h"

// Declare variables and interfaces.
IWMSServer       *pServer;
IXMLDOMDocument  *pPlaylist;
IXMLDOMElement   *pElement_Smil, *pElement_Media;
IXMLDOMNode      *pProc_Inst, *pRoot, *pNode;
CComBSTR         bstrName, bstrNamespaceURI, bstrVersion;
CComVariant      varPath, varBegin, varDuration;
HRESULT         hr;
    
// Initialize the COM library and retrieve a pointer
// to an IWMSServer interface.
hr = CoInitialize(NULL);
if (FAILED(hr))goto EXIT;

hr = CoCreateInstance(CLSID_WMSServer,
                      NULL,
                      CLSCTX_ALL,
                      IID_IWMSServer,
                      (void **)&pServer);
if (FAILED(hr))goto EXIT;

// Create the playlist object.
hr = pServer->CreatePlaylist(&pPlaylist);
if (FAILED(hr))goto EXIT;

// Create the processing instruction node.
bstrName  = "wsx";
bstrNamespaceURI = "";
hr = pPlaylist->createNode((CComVariant)NODE_PROCESSING_INSTRUCTION,
                           bstrName,
                           bstrNamespaceURI,
                           &pProc_Inst);
if (FAILED(hr))goto EXIT;

// Add the processing instruction to the file structure.
hr = pPlaylist->appendChild(pProc_Inst, &pNode);
if (FAILED(hr))goto EXIT;

bstrVersion = "version = 1.0";
pProc_Inst->put_text(bstrVersion);
    
// Create and add the root node of the playlist.
bstrName = "smil";
hr = pPlaylist->createElement(bstrName, &pElement_Smil);
if (FAILED(hr))goto EXIT;

hr = pPlaylist->appendChild(pElement_Smil, &pRoot);
if (FAILED(hr))goto EXIT;

// Create a media element and add a src attribute.
bstrName = "media";
hr = pPlaylist->createElement(bstrName, &pElement_Media);
if (FAILED(hr))goto EXIT;

bstrName = "src";
varPath = "c:\\wmput\\wmroot\\moview.wmv";
hr = pElement_Media->setAttribute(bstrName, varPath);
if (FAILED(hr))goto EXIT;

// Add the media element to the root node.
hr = pRoot->appendChild(pElement_Media, &pNode);
if (FAILED(hr))goto EXIT;

// Create a second media element and assign multiple
// attributes. Note that the server reverses the order
// of the attributes (from how they appear in the code).
bstrName = "media";
hr = pPlaylist->createElement(bstrName, &pElement_Media);
if (FAILED(hr))goto EXIT;

bstrName = "dur";
varDuration = "+.5min";
hr = pElement_Media->setAttribute(bstrName, varDuration);
if (FAILED(hr))goto EXIT;

bstrName = "clipBegin";
varBegin = "0:00";
hr = pElement_Media->setAttribute(bstrName, varBegin);
if (FAILED(hr))goto EXIT;

bstrName = "src";
varPath = "c:\\wmput\\wmroot\\movie.wmv";
hr = pElement_Media->setAttribute(bstrName, varPath);
if (FAILED(hr))goto EXIT;

// Add the media element to the root node.
hr = pRoot->appendChild(pElement_Media, &pNode);
if (FAILED(hr))goto EXIT;

// Create a third media element and add a src attribute.
bstrName = "media";
hr = pPlaylist->createElement(bstrName, &pElement_Media);
if (FAILED(hr))goto EXIT;

bstrName = "src";
varPath = "c:\\wmput\\wmroot\\ad2.wmv";
hr = pElement_Media->setAttribute(bstrName, varPath);
if (FAILED(hr))goto EXIT;

// Add the media element to the root node.
hr = pRoot->appendChild(pElement_Media, &pNode);
if (FAILED(hr))goto EXIT;

// Save the playlist.
varPath = "c:\\wmpub\\wmroot\\playlist.wsx";
hr = pPlaylist->save(varPath);
if (FAILED(hr))goto EXIT;

EXIT:
// TODO: Release temporary objects and uninitialize COM.

The preceding examples create the following playlist.

<?wsx version = '1.0' ?>
<smil>
    <media src="c:\wmpub\wmroot\ad1.wmv"/>
    <media src="c:\wmpub\wmroot\movie.wmv" clipBegin="0:00" dur="+.5min" />
    <media src="c:\wmpub\wmroot\ad2.wmv"/>
</smil>

See Also (General)

See Also (Visual Basic .NET)

See Also (C#)

See Also (C++)