Create Fields in Word documents using C# and VB.NET

Field elements in Word documents are dynamic elements, placeholders for dynamic data, or changing aspects of the document. For instance, a field can be a page reference, property reference, or date and time value.

With the GemBox.Document library you can create fields in your Word files programmatically in C# and VB.NET.

You can define fields with the Field.FieldType class and optionally with Field.InstructionInlines, which may contain additional field arguments and switches, or even other nested fields. The field's instructions (the field's code) define how Field.ResultInlines (the field's value) should be updated or calculated.

The following example shows how to create fields of different types with various arguments and switches.

using GemBox.Document;

class Program
{
    static void Main()
    {
        // If using Professional version, put your serial key below.
        ComponentInfo.SetLicense("FREE-LIMITED-KEY");

        var document = new DocumentModel();

        var section = new Section(document);
        document.Sections.Add(section);

        // Add '{ AUTHOR }' field.
        section.Blocks.Add(
            new Paragraph(document,
                new Run(document, "Author: "),
                new Field(document, FieldType.Author, null, "Mario at GemBox")));

        // Add '{ DATE }' field.
        section.Blocks.Add(
            new Paragraph(document,
                new Run(document, "Date: "),
                new Field(document, FieldType.Date)));

        // Add '{ DATE \@ "dddd, MMMM dd, yyyy" }' field.
        section.Blocks.Add(
            new Paragraph(document,
                new Run(document, "Date with specified format: "),
                new Field(document, FieldType.Date, "\\@ \"dddd, MMMM dd, yyyy\"")));

        document.Save("Fields.%OutputFileType%");
    }
}

Imports GemBox.Document

Module Program

    Sub Main()

        ' If using Professional version, put your serial key below.
        ComponentInfo.SetLicense("FREE-LIMITED-KEY")

        Dim document As New DocumentModel()

        Dim section As New Section(document)
        document.Sections.Add(section)

        ' Add '{ AUTHOR }' field.
        section.Blocks.Add(
            New Paragraph(document,
                New Run(document, "Author: "),
                New Field(document, FieldType.Author, Nothing, "Mario at GemBox")))

        ' Add '{ DATE }' field.
        section.Blocks.Add(
            New Paragraph(document,
                New Run(document, "Date: "),
                New Field(document, FieldType.Date)))

        ' Add '{ DATE \@ "dddd, MMMM dd, yyyy" }' field.
        section.Blocks.Add(
            New Paragraph(document,
                New Run(document, "Date with specified format: "),
                New Field(document, FieldType.Date, "\@ ""dddd, MMMM dd, yyyy""")))

        document.Save("Fields.%OutputFileType%")

    End Sub
End Module

On the following page, you can find a list of field codes supported by Microsoft Word. It also contains a description of each field, its syntax, and available switches.

By default, when viewing a Word document in the Microsoft Word application, the field's value is displayed, and the field's instructions are not visible. However, by pressing ALT + F9, you can toggle between the field's code and its result.

Interactive form fields are a particular type of Field elements that contain Field.FormData objects. With these types of fields you can create, read, and update fillable forms in your Word documents.