How to use OpenXML SDK in a vb.net project to change custom properties of .docx files?

Question

I'm working on a vb.net project that is supposed to use OpenXML SDK to alter custom file properties of a .docx file. Once I have the document open as a 'WordprocessingDocument`, how do I access the custom file properties?

Answer 1

Hi @Aaron Gerber ,

The custom file properties are stored in the CustomFilePropertiesPart of the document. You can access this part through the MainDocumentPart.

If the CustomFilePropertiesPart does not exist, you will need to create it before you can add or modify properties.

Imports DocumentFormat.OpenXml.Packaging
Imports DocumentFormat.OpenXml.CustomProperties
Imports DocumentFormat.OpenXml.VariantTypes

    Sub ModifyCustomProperties(docPath As String)
        Using wordDoc As WordprocessingDocument = WordprocessingDocument.Open(docPath, True)
            Dim customPropsPart As CustomFilePropertiesPart = wordDoc.CustomFilePropertiesPart

            If customPropsPart Is Nothing Then
                customPropsPart = wordDoc.AddCustomFilePropertiesPart()
                ' Add initial properties if needed
                customPropsPart.Properties = New Properties()
            End If

            Dim properties = customPropsPart.Properties

            ' Check if a property exists by name
            Dim existingProp = properties.OfType(Of CustomDocumentProperty)().
                               FirstOrDefault(Function(p) p.Name.Value = "YourPropertyName")

            If existingProp IsNot Nothing Then
                existingProp.VTLPWSTR.Text = "NewValue"
            Else
                Dim newPropId = If(properties.Elements(Of CustomDocumentProperty).Any(),
                                    properties.Elements(Of CustomDocumentProperty).Max(Function(p) CInt(p.PropertyId.Value)) + 1,
                                    1)
                Dim newProp = New CustomDocumentProperty() With {
                    .Name = "YourPropertyName",
                    .PropertyId = newPropId,
                    .VTLPWSTR = New VTLPWSTR("YourValue")
                }
                properties.AppendChild(newProp)
            End If

            customPropsPart.Properties.Save()
        End Using
    End Sub

Best Regards.

Jiachen Li

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