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IsAvailable Method
See Also  Example
Leadtools.Wia Namespace > WiaSession Class : IsAvailable Method



version
The WIA version to be used. Possible values are:

Value

Meaning

WiaVersion.Version1 Use WIA version 1.0.
WiaVersion.Version2 Use WIA version 2.0.
version
The WIA version to be used. Possible values are:

Value

Meaning

WiaVersion.Version1 Use WIA version 1.0.
WiaVersion.Version2 Use WIA version 2.0.
Determines which version of the WIA source is installed.

Syntax

Visual Basic (Declaration) 
Public Shared Function IsAvailable( _
   ByVal version As WiaVersion _
) As Boolean
Visual Basic (Usage)Copy Code
Dim version As WiaVersion
Dim value As Boolean
 
value = WiaSession.IsAvailable(version)
C# 
public static bool IsAvailable( 
   WiaVersion version
)
C++/CLI 
public:
static bool IsAvailable( 
   WiaVersion version
)

Parameters

version
The WIA version to be used. Possible values are:

Value

Meaning

WiaVersion.Version1 Use WIA version 1.0.
WiaVersion.Version2 Use WIA version 2.0.

Return Value

true if at least one WIA source of the specified version is installed, false if no WIA source is installed that supports the specified WIA version.

Example

Visual BasicCopy Code
<Test> _
Public Sub IsAvailableExample(ByVal parent As IWin32Window)
   If (Not WiaSession.IsAvailable(WiaVersion.Version1)) Then
      MessageBox.Show("WIA version 1.0 not installed.")
      Return
   End If
   Dim session As WiaSession = New WiaSession()
   session.Startup(WiaVersion.Version1)

   Dim res As DialogResult = session.SelectDeviceDlg(parent, WiaDeviceType.Default, WiaSelectSourceFlags.NoDefault)
   If res <> DialogResult.OK Then
      MessageBox.Show("Error selecting WIA device.")
      session.Shutdown()
      Return
   End If

   ' Initialize and fill the required fields from the WiaAcquireOptions structure
   Dim wiaAcquireOptions As WiaAcquireOptions = wiaAcquireOptions.Empty
   wiaAcquireOptions.MemoryBufferSize = 32 * 1024
   wiaAcquireOptions.DoubleBuffer = True
   session.AcquireOptions = wiaAcquireOptions

   AddHandler session.AcquireEvent, AddressOf session_AcquireEvent

   session.Acquire(parent, Nothing, WiaAcquireFlags.ShowUserInterface Or WiaAcquireFlags.UseCommonUI)

   RemoveHandler session.AcquireEvent, AddressOf session_AcquireEvent
   session.Shutdown()
End Sub

Public Sub session_AcquireEvent(ByVal sender As Object, ByVal e As WiaAcquireEventArgs)
   Application.DoEvents()

   If (e.Flags And WiaAcquiredPageFlags.StartOfPage) = WiaAcquiredPageFlags.StartOfPage Then
      Console.WriteLine("Beginning of data transfer.")
   ElseIf (e.Flags And WiaAcquiredPageFlags.EndOfPage) = WiaAcquiredPageFlags.EndOfPage Then
      Console.WriteLine("End of data transfer.")
   End If

   If Not e.Image Is Nothing Then
      ' You can load the image here.
   End If

   e.Cancel = False
End Sub
C#Copy Code
public void IsAvailableExample(IWin32Window parent) 
{ 
   if ( !WiaSession.IsAvailable(WiaVersion.Version1) ) 
   { 
      MessageBox.Show("WIA version 1.0 not installed."); 
      return; 
   } 
 
   WiaSession wiaSession = new WiaSession(); 
   wiaSession.Startup(WiaVersion.Version1); 
 
   DialogResult res = wiaSession.SelectDeviceDlg(parent, WiaDeviceType.Default, WiaSelectSourceFlags.NoDefault); 
   if(res != DialogResult.OK) 
   { 
      MessageBox.Show("Error selecting WIA device."); 
      wiaSession.Shutdown(); 
      return; 
   } 
 
   // Initialize and fill the required fields from the WiaAcquireOptions structure 
   WiaAcquireOptions wiaAcquireOptions = WiaAcquireOptions.Empty; 
   wiaAcquireOptions.MemoryBufferSize = 32 * 1024; 
   wiaAcquireOptions.DoubleBuffer = true; 
   wiaSession.AcquireOptions = wiaAcquireOptions; 
 
   wiaSession.AcquireEvent += new EventHandler<WiaAcquireEventArgs>(wiaSession_AcquireEvent); 
 
   wiaSession.Acquire(parent, null, WiaAcquireFlags.ShowUserInterface | WiaAcquireFlags.UseCommonUI); 
 
   wiaSession.AcquireEvent -= new EventHandler<WiaAcquireEventArgs>(wiaSession_AcquireEvent); 
   wiaSession.Shutdown(); 
} 
 
public void wiaSession_AcquireEvent(object sender, WiaAcquireEventArgs e) 
{ 
   Application.DoEvents(); 
 
   if ((e.Flags & WiaAcquiredPageFlags.StartOfPage) == WiaAcquiredPageFlags.StartOfPage) 
      Console.WriteLine("Beginning of data transfer."); 
   else if ((e.Flags & WiaAcquiredPageFlags.EndOfPage) == WiaAcquiredPageFlags.EndOfPage) 
      Console.WriteLine("End of data transfer."); 
 
   if (e.Image != null) 
   { 
      // You can load the image here. 
   } 
 
   e.Cancel = false; 
}

Remarks

Use this method to enable or disable WIA menu items.

Requirements

Target Platforms: Microsoft .NET Framework 3.0, Windows 2000, Windows XP, Windows Vista, Windows Server 2003 family, Windows Server 2008 family

See Also