IWMPMediaCollection2::createQuery 方法

该方法 createQuery 返回一个表示新查询的 IWMPQuery 接口。

语法

public IWMPQuery createQuery();

Public Function createQuery() As IWMPQuery
Implements IWMPMediaCollection2.createQuery

parameters

此方法没有任何参数。

返回值

一个 WMPLib.IWMPQuery 接口,表示新的空查询。

注解

创建新查询是创建复合查询的第一步。

示例

以下示例用于 createQuery 获取初始化为 null 的 IWMPQuery 接口。 由于此查询未添加任何条件,因此当它用作 getStringCollectionByQuery 方法中的参数时,该方法将返回包含指定媒体类型的所有媒体项的字符串集合。 然后,字符串集合将显示在列表框中。

// Get an IWMPMediaCollection2 interface so that you can access the createQuery and
// getStringCollectionByQuery methods.
WMPLib.IWMPMediaCollection2 mc = (WMPLib.IWMPMediaCollection2)player.mediaCollection;

// Create an IWMPQuery interface with no conditions added to it.
WMPLib.IWMPQuery nullQuery = mc.createQuery();

// Get a string collection that contains the titles of all the audio items in the media
// collection.
WMPLib.IWMPStringCollection2 allTitles = (WMPLib.IWMPStringCollection2)mc.getStringCollectionByQuery("Title", nullQuery, "audio", "", false);

// Display the titles by adding them to a list box.
for (int i = 0; i < allTitles.count; i++)
{
    queryResults.Items.Add(allTitles.Item(i));
}

' Get an IWMPMediaCollection2 interface so that you can access
&#39; the createQuery and getStringCollectionByQuery methods.
Dim mc As WMPLib.IWMPMediaCollection2 = player.mediaCollection

&#39; Create an IWMPQuery interface with no conditions added to it.
Dim nullQuery As WMPLib.IWMPQuery = mc.createQuery()

&#39; Get a string collection that contains the titles of all the audio items in the media
&#39; collection
Dim allTitles As WMPLib.IWMPStringCollection2 = mc.getStringCollectionByQuery(&quot;Title&quot;, nullQuery, &quot;audio&quot;, &quot;&quot;, False)

&#39; Display the titles by adding them to a ListBox
For i As Integer = 0 To (allTitles.count - 1)

    queryResults.Items.Add(allTitles.Item(i))

Next i

要求

要求
版本
Windows 媒体播放器 11.
命名空间
WMPLib
Assembly
Interop.WMPLib.dll (Interop.WMPLib.dll.dll)

另请参阅

IWMPMediaCollection2 接口 (VB和 C#)

IWMPQuery 接口 (VB和 C#)