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WiaException Class

Summary

The exception that is thrown when a WIA error occurs.

Syntax

C++

[SerializableAttribute()] 
public class WiaException : Leadtools.LeadtoolsException, System.Runtime.InteropServices._Exception, System.Runtime.Serialization.ISerializable

<SerializableAttribute()> 
Public Class WiaException  
   Inherits Leadtools.LeadtoolsException 
   Implements System.Runtime.InteropServices._Exception, System.Runtime.Serialization.ISerializable

[SerializableAttribute()] 
public ref class WiaException : public Leadtools.LeadtoolsException, System.Runtime.InteropServices._Exception, System.Runtime.Serialization.ISerializable

Remarks

The WiaException class defines a Code property that you can examine to determine what caused the error.

Default messages are implemented for each Code. You can, however, modify any message by using the GetCodeMessage and SetCodeMessage methods.

Example

                                                                                                                                               
id="CSharpExampleTab" onclick="$.selectCodeContainer(this)">C#
 id="VBExampleTab" onclick="$.selectCodeContainer(this)">VB

 codeContainer VBExample hide">Imports Leadtools  Imports Leadtools.Wia   <Test> _  style="color:Blue;">#If Not LEADTOOLS_V19_OR_LATER Then  Public Sub WiaExceptionExample(ByVal parent As IWin32Window)  style="color:Blue;">#Else  Public Sub WiaExceptionExample(ByVal parent As IntPtr)  style="color:Blue;">#End If ' #If LEADTOOLS_V19_OR_LATER Then  Dim wiaSession As WiaSession = Nothing  Try  If (Not WiaSession.IsAvailable(WiaVersion.Version1)) Then  MessageBox.Show("WIA version 1.0 not installed.")  Return  End If   ' initialize a new WIA wiaSession  wiaSession = New WiaSession()  wiaSession.Startup(WiaVersion.Version1)   Dim res As DialogResult = wiaSession.SelectDeviceDlg(parent, WiaDeviceType.Default, WiaSelectSourceFlags.NoDefault)  If res <> DialogResult.OK Then  MessageBox.Show("Error selecting WIA device.")  wiaSession.Shutdown()  Return  End If   ' acquire a page, if paper jam, allow the user to retry  Dim done As Boolean = False  Do While Not done  Try  AddHandler wiaSession.AcquireEvent, AddressOf wiaSession_AcquireEvent2   res = wiaSession.Acquire(parent, Nothing, WiaAcquireFlags.ShowUserInterface Or WiaAcquireFlags.UseCommonUI)  MessageBox.Show("Success")  done = True   RemoveHandler wiaSession.AcquireEvent, AddressOf wiaSession_AcquireEvent2  Catch ex As WiaException  If ex.Code = WiaExceptionCode.PaperJam Then  If MessageBox.Show("Paper jam.  Fix and retry?", "WIA", MessageBoxButtons.YesNo) = DialogResult.No Then  done = True  End If  Else  ' other error, propagate  Throw ex  End If  End Try  Loop  Catch ex As WiaException  MessageBox.Show(String.Format("WIA error:{0}Code: {1}{0}Message: {2}", Environment.NewLine, ex.Code, ex.Message))  Catch ex As Exception  MessageBox.Show(String.Format("Other error: Message:{0}", ex.Message))  Finally  If Not wiaSession Is Nothing Then  wiaSession.Shutdown()  End If  End Try  End Sub   Private Sub wiaSession_AcquireEvent2(ByVal sender As Object, ByVal e As WiaAcquireEventArgs)  Application.DoEvents()   If Not e.Image Is Nothing Then  e.Image.Dispose()  End If   e.Cancel = False  End Sub

codeContainer CSharpExample hide">

using Leadtools;  using Leadtools.Wia;   [TestMethod]  style="color:Blue;">#if !LEADTOOLS_V19_OR_LATER  public void WiaExceptionExample(IWin32Window parent)  style="color:Blue;">#else  public void WiaExceptionExample(IntPtr parent)  style="color:Blue;">#endif // #if !LEADTOOLS_V19_OR_LATER  {  WiaSession wiaSession = null;  try  {  if (!WiaSession.IsAvailable(WiaVersion.Version1))  {  MessageBox.Show("WIA version 1.0 not installed.");  return;  }   // initialize a new WIA 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;  }   // acquire a page, if paper jam, allow the user to retry  bool done = false;  while(!done)  {  try  {  wiaSession.AcquireEvent += new EventHandler<WiaAcquireEventArgs>(wiaSession_AcquireEvent2);   res = wiaSession.Acquire(parent, null, WiaAcquireFlags.ShowUserInterface |   WiaAcquireFlags.UseCommonUI);  MessageBox.Show("Success");  done = true;   wiaSession.AcquireEvent -= new EventHandler<WiaAcquireEventArgs>(wiaSession_AcquireEvent2);  }  catch(WiaException ex)  {  if(ex.Code == WiaExceptionCode.PaperJam)  {  if(MessageBox.Show("Paper jam.  Fix and retry?", "WIA", MessageBoxButtons.YesNo) == DialogResult.No)  done = true;  }  else  {  // other error, propagate  throw ex;  }  }  }  }  catch(WiaException ex)  {  MessageBox.Show(string.Format("WIA error:{0}Code: {1}{0}Message: {2}", Environment.NewLine, ex.Code, ex.Message));  }  catch(Exception ex)  {  MessageBox.Show(string.Format("Other error: Message:{0}", ex.Message));  }  finally  {  if(wiaSession != null)  wiaSession.Shutdown();  }  }   void wiaSession_AcquireEvent2(object sender, WiaAcquireEventArgs e)  {  Application.DoEvents();   if (e.Image != null)  e.Image.Dispose();   e.Cancel = false;  }