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GetPropertyString Method
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Leadtools.Wia Namespace > WiaSession Class : GetPropertyString 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 a string buffer for any WIA property of type WiaVariableTypes.Bstr.

Syntax

Visual Basic (Declaration) 
Public Sub GetPropertyString( _
   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.GetPropertyString(item, propertyIdName, propertyId)
C# 
public void GetPropertyString( 
   object item,
   string propertyIdName,
   WiaPropertyId propertyId
)
C++/CLI 
public:
void GetPropertyString( 
   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
Public Sub GetPropertyStringExample(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.DigitalCamera, WiaSelectSourceFlags.NoDefault)
   If res <> DialogResult.OK Then
      MessageBox.Show("Error selecting WIA device.")
      session.Shutdown()
      Return
   End If

   session.GetRootItem(Nothing)
   If Not session.RootItem Is Nothing Then
      ' if you have a digital camera device that supports EXIF format, then you
      ' can populate the artist field in every EXIF image that it captures.
      session.GetPropertyString(session.RootItem, Nothing, WiaPropertyId.CameraDeviceArtist)
      Console.WriteLine("Old Device Artist: {0}", session.StringValue)

      ' You can also change the artist if you like to.
      session.StringValue = "I am the new artist."
      session.SetPropertyString(session.RootItem, Nothing, WiaPropertyId.CameraDeviceArtist)
      Console.WriteLine("New Device Artist: {0}", session.StringValue)
   End If

   session.Shutdown()
End Sub
C#Copy Code
public void GetPropertyStringExample(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.DigitalCamera, WiaSelectSourceFlags.NoDefault); 
   if (res != DialogResult.OK) 
   { 
      MessageBox.Show("Error selecting WIA device."); 
      wiaSession.Shutdown(); 
      return; 
   } 
 
   wiaSession.GetRootItem(null); 
   if (wiaSession.RootItem != null) 
   { 
      // if you have a digital camera device that supports EXIF format, then you  
      // can populate the artist field in every EXIF image that it captures. 
      wiaSession.GetPropertyString(wiaSession.RootItem, null, WiaPropertyId.CameraDeviceArtist); 
      Console.WriteLine("Old Device Artist: {0}", wiaSession.StringValue); 
 
      // You can also change the artist if you like to. 
      wiaSession.StringValue = "I am the new artist."; 
      wiaSession.SetPropertyString(wiaSession.RootItem, null, WiaPropertyId.CameraDeviceArtist); 
      Console.WriteLine("New Device Artist: {0}", wiaSession.StringValue); 
   } 
 
   wiaSession.Shutdown(); 
}

Remarks

Call this function to retrieve the string buffer value for any WIA property of type WiaVariableTypes.Bstr (for instance, WiaPropertyId.DeviceInfoDevName , WiaPropertyId.ItemFullItemName , ...etc).

After calling this method the StringValue property will become available for you to use to get the retrieved String.

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