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IsAvailable Method

Summary

Determines which version of the WIA source is installed.

Syntax

C++

public static bool IsAvailable( 
   WiaVersion version 
)

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

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.

Remarks

Use this method to enable or disable WIA menu items.

Example

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Wia; 
 
public void IsAvailableExample(IntPtr 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; 
}

Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.Wia 
 
 
<TestMethod()> _ 
Public Sub IsAvailableExample(ByVal parent As IntPtr) 
   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