IFeatureSupport.GetVersionPresent 方法

检索指定功能的版本。

**命名空间:**System.Windows.Forms
**程序集:**System.Windows.Forms（在 system.windows.forms.dll 中）

语法

声明
Function GetVersionPresent ( _
    feature As Object _
) As Version
用法
Dim instance As IFeatureSupport
Dim feature As Object
Dim returnValue As Version

returnValue = instance.GetVersionPresent(feature)

Version GetVersionPresent (
    Object feature
)

Version^ GetVersionPresent (
    Object^ feature
)

Version GetVersionPresent (
    Object feature
)

function GetVersionPresent (
    feature : Object
) : Version

参数

• feature
  所要求版本的功能。

返回值

表示指定功能的版本号的 Version；如果该功能未安装，则为 空引用（在 Visual Basic 中为 Nothing）。

备注

有关此方法的实现，请参见 GetVersionPresent。

示例

下面的示例使用 IFeatureSupport 的 OSFeature 实现并查询 LayeredWindows 功能。检查版本是否为 空引用（在 Visual Basic 中为 Nothing），以确定该功能是否存在。结果显示在文本框内。此代码假定已经创建 textBox1 并将其放置在窗体上。

Private Sub LayeredWindows()
    ' Gets the version of the layered windows feature.
    Dim myVersion As Version = _
       OSFeature.Feature.GetVersionPresent(OSFeature.LayeredWindows)
       
    ' Prints whether the feature is available.
    If Not (myVersion Is Nothing) Then
        textBox1.Text = "Layered windows feature is installed." & _
           ControlChars.CrLf
    Else
        textBox1.Text = "Layered windows feature is not installed." & _
           ControlChars.CrLf
    End If 
    'This is an alternate way to check whether a feature is present.
    If OSFeature.Feature.IsPresent(OSFeature.LayeredWindows) Then
        textBox1.Text &= "Again, layered windows feature is installed."
    Else
        textBox1.Text &= "Again, layered windows feature is not installed."
    End If
End Sub

private void LayeredWindows() {
   // Gets the version of the layered windows feature.
   Version myVersion = OSFeature.Feature.GetVersionPresent(OSFeature.LayeredWindows);

   // Prints whether the feature is available.
   if (myVersion != null)
      textBox1.Text = "Layered windows feature is installed." + '\n';
   else
      textBox1.Text = "Layered windows feature is not installed." + '\n';

   // This is an alternate way to check whether a feature is present.
   if (OSFeature.Feature.IsPresent(OSFeature.LayeredWindows))
      textBox1.Text += "Again, layered windows feature is installed.";
   else
      textBox1.Text += "Again, layered windows feature is not installed.";
}

private:
   void LayeredWindows()
   {
      // Gets the version of the layered windows feature.
      Version^ myVersion = OSFeature::Feature->GetVersionPresent(
         OSFeature::LayeredWindows );
      
      // Prints whether the feature is available.
      if ( myVersion != nullptr )
      {
         textBox1->Text = "Layered windows feature is installed.\n";
      }
      else
      {
         textBox1->Text = "Layered windows feature is not installed.\n";
      }

      
      // This is an alternate way to check whether a feature is present.
      if ( OSFeature::Feature->IsPresent( OSFeature::LayeredWindows ) )
      {
         textBox1->Text = String::Concat( textBox1->Text,
            "Again, layered windows feature is installed." );
      }
      else
      {
         textBox1->Text = String::Concat( textBox1->Text,
            "Again, layered windows feature is not installed." );
      }
   }

private void LayeredWindows()
{
    // Gets the version of the layered windows feature.
    Version myVersion = OSFeature.get_Feature().GetVersionPresent
        (OSFeature.LayeredWindows);

    // Prints whether the feature is available.
    if (myVersion != null) {
        textBox1.set_Text("Layered windows feature is installed." 
            + '\n');
    }
    else {
        textBox1.set_Text("Layered windows feature is not installed." 
            + '\n');
    }

    // This is an alternate way to check whether a feature is present.
    if (OSFeature.get_Feature().IsPresent(OSFeature.LayeredWindows)) {
        textBox1.set_Text(textBox1.get_Text()
            + "Again, layered windows feature is installed.");
    }
    else {
        textBox1.set_Text(textBox1.get_Text() 
            + "Again, layered windows feature is not installed.");
    }
} //LayeredWindows 

平台

Windows 98、Windows 2000 SP4、Windows CE、Windows Millennium Edition、Windows Mobile for Pocket PC、Windows Mobile for Smartphone、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition

.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。

版本信息

.NET Framework

受以下版本支持：2.0、1.1、1.0

请参见

参考

IFeatureSupport 接口
IFeatureSupport 成员
System.Windows.Forms 命名空间
GetVersionPresent
OSFeature
FeatureSupport 类