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



item
Handle to the item which represents the item having the property. You can retrieve this parameter by either calling the WiaSession.GetRootItem method to get the device’s root item itself or by enumerating the child items of the device through a call to EnumChildItems method.
propertyIdName

This string should contain the equivalent property Id string for the WIA property ID. Use the see GetPropertyIdString method to get this string for the property ID.

If you passed null for this parameter then the WIA toolkit will use the property ID passed through the third parameter propertyId; otherwise this parameters will be used whether or not you passed valid property ID through the propertyId parameter

propertyId

The property ID for the value being sought, for list of available property IDs see WiaPropertyId.

This parameter is required only if the second parameter "propertyIdName"is null; otherwise you can pass 0 for this parameter.

item
Handle to the item which represents the item having the property. You can retrieve this parameter by either calling the WiaSession.GetRootItem method to get the device’s root item itself or by enumerating the child items of the device through a call to EnumChildItems method.
propertyIdName

This string should contain the equivalent property Id string for the WIA property ID. Use the see GetPropertyIdString method to get this string for the property ID.

If you passed null for this parameter then the WIA toolkit will use the property ID passed through the third parameter propertyId; otherwise this parameters will be used whether or not you passed valid property ID through the propertyId parameter

propertyId

The property ID for the value being sought, for list of available property IDs see WiaPropertyId.

This parameter is required only if the second parameter "propertyIdName"is null; otherwise you can pass 0 for this parameter.

Retrieves the Guid structure for any WIA property of type WiaVariableTypes.Clsid .

Syntax

Visual Basic (Declaration) 
Public Sub GetPropertyGuid( _
   ByVal item As Object, _
   ByVal propertyIdName As String, _
   ByVal propertyId As WiaPropertyId _
)
Visual Basic (Usage)Copy Code
Dim instance As WiaSession
Dim item As Object
Dim propertyIdName As String
Dim propertyId As WiaPropertyId
 
instance.GetPropertyGuid(item, propertyIdName, propertyId)
C# 
public void GetPropertyGuid( 
   object item,
   string propertyIdName,
   WiaPropertyId propertyId
)
C++/CLI 
public:
void GetPropertyGuid( 
   Object^ item,
   String^ propertyIdName,
   WiaPropertyId propertyId
)

Parameters

item
Handle to the item which represents the item having the property. You can retrieve this parameter by either calling the WiaSession.GetRootItem method to get the device’s root item itself or by enumerating the child items of the device through a call to EnumChildItems method.
propertyIdName

This string should contain the equivalent property Id string for the WIA property ID. Use the see GetPropertyIdString method to get this string for the property ID.

If you passed null for this parameter then the WIA toolkit will use the property ID passed through the third parameter propertyId; otherwise this parameters will be used whether or not you passed valid property ID through the propertyId parameter

propertyId

The property ID for the value being sought, for list of available property IDs see WiaPropertyId.

This parameter is required only if the second parameter "propertyIdName"is null; otherwise you can pass 0 for this parameter.

Example

Visual BasicCopy Code
Dim mySession As WiaSession
Public Sub GetPropertyGuidExample(ByVal parent As IWin32Window)
   If (Not wiaSession.IsAvailable(WiaVersion.Version1)) Then
      MessageBox.Show("WIA version 1.0 not installed.")
      Return
   End If

   mySession = New WiaSession()
   mySession.Startup(WiaVersion.Version1)

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

   mySession.GetRootItem(Nothing)
   If Not mySession.RootItem Is Nothing Then
      AddHandler mySession.EnumItemsEvent, AddressOf session_EnumItemsEvent3

      mySession.EnumChildItems(mySession.RootItem)

      RemoveHandler mySession.EnumItemsEvent, AddressOf session_EnumItemsEvent3
   End If

   mySession.Shutdown()
End Sub

Private Sub session_EnumItemsEvent3(ByVal sender As Object, ByVal e As WiaEnumItemsEventArgs)
   Dim found As Boolean = False

   If Not e.Item Is Nothing Then
      ' Read the item category property (this property is only available for WIA 2.0).
      mySession.GetPropertyGuid(e.Item, Nothing, WiaPropertyId.ItemCategory)

      ' Find the related item category for the received Guid.
      WiaSession.GetCategoryGuid(WiaCategories.Feeder)
      If wiaSession.CategoryGuid = mySession.GuidValue Then ' the item is a Feeder.
         Console.WriteLine("Item category: Feeder")
         found = True
      End If

      If found = False Then
         WiaSession.GetCategoryGuid(WiaCategories.FeederBack)
         If WiaSession.CategoryGuid = mySession.GuidValue Then ' the item is a Feeder.
            Console.WriteLine("Item category: FeederBack")
            found = True
         End If
      End If

      If found = False Then
         WiaSession.GetCategoryGuid(WiaCategories.FeederFront)
         If wiaSession.CategoryGuid = mySession.GuidValue Then ' the item is a Feeder.
            Console.WriteLine("Item category: FeederFront")
            found = True
         End If
      End If

      If found = False Then
         WiaSession.GetCategoryGuid(WiaCategories.Film)
         If wiaSession.CategoryGuid = mySession.GuidValue Then ' the item is a Feeder.
            Console.WriteLine("Item category: Film")
            found = True
         End If
      End If

      If found = False Then
         WiaSession.GetCategoryGuid(WiaCategories.FinishedFile)
         If wiaSession.CategoryGuid = mySession.GuidValue Then ' the item is a Feeder.
            Console.WriteLine("Item category: FinishedFile")
            found = True
         End If
      End If

      If found = False Then
         WiaSession.GetCategoryGuid(WiaCategories.Flatbed)
         If wiaSession.CategoryGuid = mySession.GuidValue Then ' the item is a Feeder.
            Console.WriteLine("Item category: Flatbed")
            found = True
         End If
      End If

      If found = False Then
         WiaSession.GetCategoryGuid(WiaCategories.Folder)
         If wiaSession.CategoryGuid = mySession.GuidValue Then ' the item is a Feeder.
            Console.WriteLine("Item category: Folder")
            found = True
         End If
      End If

      If found = False Then
         WiaSession.GetCategoryGuid(WiaCategories.Root)
         If wiaSession.CategoryGuid = mySession.GuidValue Then ' the item is a Feeder.
            Console.WriteLine("Item category: Root")
            found = True
         End If
      End If

      session.FreeItem(e.Item)
   End If
End Sub
C#Copy Code
WiaSession mySession; 
public void GetPropertyGuidExample(IWin32Window parent) 
{ 
   if (!WiaSession.IsAvailable(WiaVersion.Version1)) 
   { 
      MessageBox.Show("WIA version 1.0 not installed."); 
      return; 
   } 
 
   mySession = new WiaSession(); 
   mySession.Startup(WiaVersion.Version1); 
 
   DialogResult res = mySession.SelectDeviceDlg(parent, WiaDeviceType.Default, WiaSelectSourceFlags.NoDefault); 
   if (res != DialogResult.OK) 
   { 
      MessageBox.Show("Error selecting WIA device."); 
      mySession.Shutdown(); 
      return; 
   } 
 
   mySession.GetRootItem(null); 
   if (mySession.RootItem != null) 
   { 
      mySession.EnumItemsEvent += new EventHandler<WiaEnumItemsEventArgs>(wiaSession_EnumItemsEvent3); 
 
      mySession.EnumChildItems(mySession.RootItem); 
 
      mySession.EnumItemsEvent -= new EventHandler<WiaEnumItemsEventArgs>(wiaSession_EnumItemsEvent3); 
   } 
 
   mySession.Shutdown(); 
} 
 
void wiaSession_EnumItemsEvent3(object sender, WiaEnumItemsEventArgs e) 
{ 
   bool found = false; 
 
   if (e.Item != null) 
   { 
      // Read the item category property (this property is only available for WIA 2.0). 
      mySession.GetPropertyGuid(e.Item, null, WiaPropertyId.ItemCategory); 
 
      // Find the related item category for the received Guid. 
      WiaSession.GetCategoryGuid(WiaCategories.Feeder); 
      if (WiaSession.CategoryGuid == mySession.GuidValue)   // the item is a Feeder. 
      { 
         Console.WriteLine("Item category: Feeder"); 
         found = true; 
      } 
 
      if (found == false) 
      { 
         WiaSession.GetCategoryGuid(WiaCategories.FeederBack); 
         if (WiaSession.CategoryGuid == mySession.GuidValue)   // the item is a Feeder. 
         { 
            Console.WriteLine("Item category: FeederBack"); 
            found = true; 
         } 
      } 
 
      if (found == false) 
      { 
         WiaSession.GetCategoryGuid(WiaCategories.FeederFront); 
         if (WiaSession.CategoryGuid == mySession.GuidValue)   // the item is a Feeder. 
         { 
            Console.WriteLine("Item category: FeederFront"); 
            found = true; 
         } 
      } 
 
      if (found == false) 
      { 
         WiaSession.GetCategoryGuid(WiaCategories.Film); 
         if (WiaSession.CategoryGuid == mySession.GuidValue)   // the item is a Feeder. 
         { 
            Console.WriteLine("Item category: Film"); 
            found = true; 
         } 
      } 
 
      if (found == false) 
      { 
         WiaSession.GetCategoryGuid(WiaCategories.FinishedFile); 
         if (WiaSession.CategoryGuid == mySession.GuidValue)   // the item is a Feeder. 
         { 
            Console.WriteLine("Item category: FinishedFile"); 
            found = true; 
         } 
      } 
 
      if (found == false) 
      { 
         WiaSession.GetCategoryGuid(WiaCategories.Flatbed); 
         if (WiaSession.CategoryGuid == mySession.GuidValue)   // the item is a Feeder. 
         { 
            Console.WriteLine("Item category: Flatbed"); 
            found = true; 
         } 
      } 
 
      if (found == false) 
      { 
         WiaSession.GetCategoryGuid(WiaCategories.Folder); 
         if (WiaSession.CategoryGuid == mySession.GuidValue)   // the item is a Feeder. 
         { 
            Console.WriteLine("Item category: Folder"); 
            found = true; 
         } 
      } 
 
      if (found == false) 
      { 
         WiaSession.GetCategoryGuid(WiaCategories.Root); 
         if (WiaSession.CategoryGuid == mySession.GuidValue)   // the item is a Feeder. 
         { 
            Console.WriteLine("Item category: Root"); 
            found = true; 
         } 
      } 
 
      mySession.FreeItem(e.Item); 
   } 
}

Remarks

Any WIA property of type WiaVariableTypes.Clsid (for example, WiaPropertyId.ItemFormat ) returns a Guid structure. In order to retrieve this type of properties you need to call the function GetPropertyGuid.

After calling this method the GuidValue property will become available for you to use to get the retrieved Guid structure.

For more information, refer to Managing WIA Sources.

Requirements

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

See Also