IWMPPlaylist：：attributeCount 属性

[与此页面关联的功能（Windows 媒体播放器 SDK）是旧版功能。 它已被 MediaPlayer 取代。 MediaPlayer 已针对Windows 10和Windows 11进行了优化。 如果可能，Microsoft 强烈建议新代码使用 MediaPlayer 而不是 Windows 媒体播放器 SDK。 如果可能，Microsoft 建议重写使用旧 API 的现有代码以使用新 API。]

attributeCount 属性获取与播放列表关联的属性数。

语法

public System.Int32 attributeCount {get; set;}

Public ReadOnly Property attributeCount As System.Int32

属性值

System.Int32，表示与播放列表关联的属性数。

备注

由于播放列表可能来自许多不同的源，因此它们可以具有多个不同的属性集。 此属性获取与特定播放列表关联的属性总数，以便 IWMPPlaylist 接口的其他成员可以访问它们。

在使用此属性之前，必须具有对库的读取访问权限。 有关详细信息，请参阅 库访问。

有关Windows 媒体播放器支持的属性的详细信息，请参阅属性参考。

示例

下面的示例演示了如何使用 IWMPPlaylist 和 IWMPMedia 接口的各种属性和方法，方法是使用当前播放列表的节点、播放列表属性、播放列表中的媒体项和媒体项属性填充树视图控件。 AxWMPLib.AxWindowsMediaPlayer 对象由名为 player 的变量表示。

WMPLib.IWMPPlaylist playlist = player.currentPlaylist;
WMPLib.IWMPMedia media;
string name;

// Demonstrates setItemInfo()
playlist.setItemInfo("custom playlist attribute", "changed");
playlist.get_Item(0).setItemInfo("new custom attribute", "5");

// Create a tree node for each playlist attribute and a subnode for the item info of that attribute.
System.Windows.Forms.TreeNode playlistRootNode = new System.Windows.Forms.TreeNode("Playlist Attributes");

for (int i = 0; i < playlist.attributeCount; ++i)
{
    // Add a tree node for each playlist attribute.
    string attribute = playlist.get_attributeName(i);
    playlistRootNode.Nodes.Add(new System.Windows.Forms.TreeNode(attribute));

    // Add a subnode for the item info for that attribute.
    string info = playlist.getItemInfo(attribute);
    playlistRootNode.Nodes[i].Nodes.Add(new System.Windows.Forms.TreeNode(info));
}

// Add the playlist root node to the tree
displayAttributes.Nodes.Add(playlistRootNode);

// Add nodes for each media item and subnodes for each attribute of that item.
System.Windows.Forms.TreeNode mediaRootNode = new System.Windows.Forms.TreeNode("Media Items in the Playlist");
for(int i = 0; i < playlist.count; i++)
{
    // Get the media item
    media = playlist.get_Item(i);

    // Add a tree node for each media item in the playlist.
    mediaRootNode.Nodes.Add(new System.Windows.Forms.TreeNode(media.name));

    // Add a child node for each attribute of the media item
    for(int j = 0; j < media.attributeCount; j++)
    {
        name = media.getAttributeName(j);
        mediaRootNode.Nodes[i].Nodes.Add(new System.Windows.Forms.TreeNode(name + ": " + media.getItemInfo(name)));
    }
}

// Add the media root node to the tree
displayAttributes.Nodes.Add(mediaRootNode);

Dim playlist As WMPLib.IWMPPlaylist = player.currentPlaylist
Dim Media As WMPLib.IWMPMedia
Dim name As String

' Demonstrates setItemInfo()
playlist.setItemInfo("custom playlist attribute", "changed")
playlist.Item(0).setItemInfo("new custom attribute", "5")

' Create a tree node for each playlist attribute and a subnode for the item info of that attribute.
Dim playlistRootNode As System.Windows.Forms.TreeNode = New System.Windows.Forms.TreeNode("Playlist Attributes")

For i As Integer = 0 To (playlist.attributeCount - 1) Step 1

    ' Add a tree node for each playlist attribute.
    Dim attribute As String = playlist.attributeName(i)
    playlistRootNode.Nodes.Add(New System.Windows.Forms.TreeNode(attribute))

    ' Add a subnode for the item info for that attribute.
    Dim info As String = playlist.getItemInfo(attribute)
    playlistRootNode.Nodes(i).Nodes.Add(New System.Windows.Forms.TreeNode(info))

Next i

' Add the playlist root node to the tree
displayAttributes.Nodes.Add(playlistRootNode)

' Add nodes for each media item and subnodes for each attribute of that item.
Dim mediaRootNode As System.Windows.Forms.TreeNode = New System.Windows.Forms.TreeNode("Media Items in the Playlist")

For i As Integer = 0 To (playlist.count - 1) Step 1

    ' Get the media item
    Media = playlist.Item(i)

    ' Add a tree node for each media item in the playlist.
    mediaRootNode.Nodes.Add(New System.Windows.Forms.TreeNode(Media.name))

    ' Add a child node for each attribute of the media item
    For j As Integer = 0 To (Media.attributeCount - 1) Step 1

        name = Media.getAttributeName(j)
        mediaRootNode.Nodes(i).Nodes.Add(New System.Windows.Forms.TreeNode(name + ": " + Media.getItemInfo(name)))

    Next j

Next i

' Add the media root node to the tree
displayAttributes.Nodes.Add(mediaRootNode)

要求

要求	值
版本	Windows 媒体播放器 9 系列或更高版本
命名空间	WMPLib
程序集	Interop.WMPLib.dll (Interop.WMPLib.dll.dll)

另请参阅

IWMPPlaylist 接口 (VB 和 C#)