VB.NET Retrieve Built-in Property / VB.NET Extract Built-in Property
Some differentiable information can be stored in a built-in property, for example, keywords in a Word document. The following VB.NET code uses System.Reflection members to get the Built-in property
The code needs the following directives
Imports Office = Microsoft.Office.Core
Imports Word = Microsoft.Office.Interop.Word
Imports System.Reflection
It also needs the following declarations
Dim oWA As Word.Application = New Word.Application
Dim oWD As Word.Document
The following code that extracts the value stored in ‘Subject’ property:
Sub GetBuiltInProp()
Try
Dim oBuiltProps As Object
oWA.Visible = True
oWD = oWA.Documents.Open("C:\ShasurData\DND_DEC_2008.doc")
oBuiltProps = oWD.BuiltInDocumentProperties
Dim oTypeBuiltProps As Type = oBuiltProps.GetType
Dim sPropertyName As String = "Subject"
Dim oProperty As Object = oTypeBuiltProps.InvokeMember("Item", BindingFlags.Default Or BindingFlags.GetProperty, Nothing, oBuiltProps, New [Object]() {1})
Dim oTypeProp As Type = oProperty.GetType
Dim sPropertyValue As String = oTypeProp.InvokeMember("Value", BindingFlags.Default Or BindingFlags.GetProperty, Nothing, oProperty, New [Object]() {})
Catch ex As Exception
Console.WriteLine(ex.Message)
Finally
oWD.Close(False)
oWA.Quit()
End Try
End Sub
Here we are retrieving the built-in property of the document using
oWD = oWA.Documents.Open("C:\ShasurData\DND_DEC_2008.doc")
oBuiltProps = oWD.BuiltInDocumentProperties
Then using the System.type class’s GetType and InvokeMethod to get to the built-in property
Dim oTypeBuiltProps As Type = oBuiltProps.GetType
Dim sPropertyName As String = "Subject"
Dim oProperty As Object = oTypeBuiltProps.InvokeMember("Item", BindingFlags.Default Or BindingFlags.GetProperty, Nothing, oBuiltProps, New [Object]() {1})
The builtindocument property collection has many Items. Hence we get the Item first through InvokeMember and then use the object to retrieve the value of that particular item
Dim oTypeProp As Type = oProperty.GetType
Dim sPropertyValue As String = oTypeProp.InvokeMember("Value", BindingFlags.Default Or BindingFlags.GetProperty, Nothing, oProperty, New [Object]() {})
The above method overcomes the "Unable to cast COM object of type 'System.__ComObject' to interface type 'Microsoft.Office.Core.DocumentProperties'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{2DF8D04D-5BFA-101B-BDE5-00AA0044DE52}' failed due to the following error: No such interface supported (Exception from HRESULT: 0x80004002 (E_NOINTERFACE))." error
Please feel free to modify and suggest improvements
See also How to Insert Document Properties in Word Document
work ONLY with office SP1 OR greater!
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