IsAvailable Method

Visual Basic
C#
WinRT C#
WinRT JavaScript
C++

public static bool IsAvailable( 
   WiaVersion version
)

'Declaration
 
Public Shared Function IsAvailable( _
   ByVal version As WiaVersion _
) As Boolean

'Usage
 
Dim version As WiaVersion
Dim value As Boolean
 
value = WiaSession.IsAvailable(version)

public static bool IsAvailable( 
   WiaVersion version
)

 function Leadtools.Wia.WiaSession.IsAvailable( 
   version 
)

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.

Use this method to enable or disable WIA menu items.

Visual Basic
C#
WinRT C#
WinRT JavaScript
Silverlight C#
Silverlight VB

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

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;
}

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

WiaSession Class
WiaSession Members
Startup Method
Shutdown Method
SelectDevice Method
SelectDeviceDlg Method
Acquire Method
AcquireToFile Method
AcquireSimple Method