GetPropertyGuid Method

Summary

Retrieves the Guid structure for any WiaVariableTypes.Clsid property.

Syntax
C#
VB
C++
public Guid GetPropertyGuid( 
   object item, 
   string propertyIdName, 
   WiaPropertyId propertyId 
) 
  
Public Function GetPropertyGuid( _ 
   ByVal item As Object, _ 
   ByVal propertyIdName As String, _ 
   ByVal propertyId As WiaPropertyId _ 
) As Guid 
public: 
Guid 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 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 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 parameter 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 a 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.

Return Value

The WIA GUID value.

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.

For more information, refer to Managing WIA Sources.

Example
C#
VB
using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Wia; 
 
WiaSession mySession; 
public void GetPropertyGuidExample(IntPtr 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; 
   } 
 
   object rootItem = mySession.GetRootItem(null); 
   if (rootItem != null) 
   { 
      mySession.EnumItemsEvent += new EventHandler<WiaEnumItemsEventArgs>(wiaSession_EnumItemsEvent3); 
 
      mySession.EnumChildItems(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). 
      Guid sessionCategoryGuid = mySession.GetPropertyGuid(e.Item, null, WiaPropertyId.ItemCategory); 
 
      // Find the related item category for the received Guid. 
      Guid categoryGuid = WiaSession.GetCategoryGuid(WiaCategories.Feeder); 
      if (categoryGuid == sessionCategoryGuid)   // the item is a Feeder. 
      { 
         Console.WriteLine("Item category: Feeder"); 
         found = true; 
      } 
 
      if (found == false) 
      { 
         categoryGuid = WiaSession.GetCategoryGuid(WiaCategories.FeederBack); 
         if (categoryGuid == sessionCategoryGuid)   // the item is a Feeder. 
         { 
            Console.WriteLine("Item category: FeederBack"); 
            found = true; 
         } 
      } 
 
      if (found == false) 
      { 
         categoryGuid = WiaSession.GetCategoryGuid(WiaCategories.FeederFront); 
         if (categoryGuid == sessionCategoryGuid)   // the item is a Feeder. 
         { 
            Console.WriteLine("Item category: FeederFront"); 
            found = true; 
         } 
      } 
 
      if (found == false) 
      { 
         categoryGuid = WiaSession.GetCategoryGuid(WiaCategories.Film); 
         if (categoryGuid == sessionCategoryGuid)   // the item is a Feeder. 
         { 
            Console.WriteLine("Item category: Film"); 
            found = true; 
         } 
      } 
 
      if (found == false) 
      { 
         categoryGuid = WiaSession.GetCategoryGuid(WiaCategories.FinishedFile); 
         if (categoryGuid == sessionCategoryGuid)   // the item is a Feeder. 
         { 
            Console.WriteLine("Item category: FinishedFile"); 
            found = true; 
         } 
      } 
 
      if (found == false) 
      { 
         categoryGuid = WiaSession.GetCategoryGuid(WiaCategories.Flatbed); 
         if (categoryGuid == sessionCategoryGuid)   // the item is a Feeder. 
         { 
            Console.WriteLine("Item category: Flatbed"); 
            found = true; 
         } 
      } 
 
      if (found == false) 
      { 
         categoryGuid = WiaSession.GetCategoryGuid(WiaCategories.Folder); 
         if (categoryGuid == sessionCategoryGuid)   // the item is a Feeder. 
         { 
            Console.WriteLine("Item category: Folder"); 
            found = true; 
         } 
      } 
 
      if (found == false) 
      { 
         categoryGuid = WiaSession.GetCategoryGuid(WiaCategories.Root); 
         if (categoryGuid == sessionCategoryGuid)   // the item is a Feeder. 
         { 
            Console.WriteLine("Item category: Root"); 
            found = true; 
         } 
      } 
 
      mySession.FreeItem(e.Item); 
   } 
} 
Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.Wia 
 
Dim mySession As WiaSession 
<TestMethod()> _ 
Public Sub GetPropertyGuidExample(ByVal parent As IntPtr) 
   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 
 
   Dim rootItem As Object = mySession.GetRootItem(Nothing) 
   If Not rootItem Is Nothing Then 
      AddHandler mySession.EnumItemsEvent, AddressOf session_EnumItemsEvent3 
 
      mySession.EnumChildItems(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). 
      Dim sessionCategoryGuid As Guid = mySession.GetPropertyGuid(e.Item, Nothing, WiaPropertyId.ItemCategory) 
 
      ' Find the related item category for the received GUID. 
      Dim categoryGuid As Guid = wiaSession.GetCategoryGuid(WiaCategories.Feeder) 
      If categoryGuid = sessionCategoryGuid Then ' the item is a Feeder. 
         Console.WriteLine("Item category: Feeder") 
         found = True 
      End If 
 
      If found = False Then 
         categoryGuid = wiaSession.GetCategoryGuid(WiaCategories.FeederBack) 
         If categoryGuid = sessionCategoryGuid Then ' the item is a Feeder. 
            Console.WriteLine("Item category: FeederBack") 
            found = True 
         End If 
      End If 
 
      If found = False Then 
         categoryGuid = wiaSession.GetCategoryGuid(WiaCategories.FeederFront) 
         If categoryGuid = sessionCategoryGuid Then ' the item is a Feeder. 
            Console.WriteLine("Item category: FeederFront") 
            found = True 
         End If 
      End If 
 
      If found = False Then 
         categoryGuid = wiaSession.GetCategoryGuid(WiaCategories.Film) 
         If categoryGuid = sessionCategoryGuid Then ' the item is a Feeder. 
            Console.WriteLine("Item category: Film") 
            found = True 
         End If 
      End If 
 
      If found = False Then 
         categoryGuid = wiaSession.GetCategoryGuid(WiaCategories.FinishedFile) 
         If categoryGuid = sessionCategoryGuid Then ' the item is a Feeder. 
            Console.WriteLine("Item category: FinishedFile") 
            found = True 
         End If 
      End If 
 
      If found = False Then 
         categoryGuid = wiaSession.GetCategoryGuid(WiaCategories.Flatbed) 
         If categoryGuid = sessionCategoryGuid Then ' the item is a Feeder. 
            Console.WriteLine("Item category: Flatbed") 
            found = True 
         End If 
      End If 
 
      If found = False Then 
         categoryGuid = wiaSession.GetCategoryGuid(WiaCategories.Folder) 
         If categoryGuid = sessionCategoryGuid Then ' the item is a Feeder. 
            Console.WriteLine("Item category: Folder") 
            found = True 
         End If 
      End If 
 
      If found = False Then 
         categoryGuid = wiaSession.GetCategoryGuid(WiaCategories.Root) 
         If categoryGuid = sessionCategoryGuid 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 

Requirements

Target Platforms

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