How to change group name of merge fields in the Word document

Syncfusion® Essential® DocIO is a .NET Word library used to create, read, edit, and convert Word documents programmatically without Microsoft Word or interop dependencies. Using this library, you can change group name of merge fields in the Word document using C#.

By using GetMergeGroupNames() to get all merge group names present in the document. Then iterate through merge group names. Use FindAllItemsByProperty() to locate the merge field with the matching FieldName. Modify the FieldName of merge field as needed.

Steps to change group name of merge fields in the Word document:

1. Create a new .NET Core console application project.
2. Install the Syncfusion.DocIO.Net.Core NuGet package as a reference to your project from NuGet.org.
   
   

3. Include the following namespaces in Program.cs file
   C#

using Syncfusion.DocIO;
using Syncfusion.DocIO.DLS;

4. Use the following code example to modify the font during a mail merge.
   C#

using (FileStream fileStream = new FileStream(Path.GetFullPath(@"Data/Template.docx"), FileMode.Open, FileAccess.ReadWrite))
{
   //Opens the template document.
   using (WordDocument document = new WordDocument(fileStream, FormatType.Docx))
   {
       // Retrieve all merge field group names present in the document.
       string[] mergeGroupNames = document.MailMerge.GetMergeGroupNames();
       //Modify group names in the document
       ModifyGroupName(document, mergeGroupNames);
       //Creates file stream.
       using (FileStream outputStream = new FileStream(Path.GetFullPath(@"Output/Result.docx"), FileMode.Create, FileAccess.ReadWrite))
       {
           //Saves the Word document to file stream.
           document.Save(outputStream, FormatType.Docx);
       }
   }
}

5. Use the following Helper method to change group name of merge fields in the Word document.
   C#

private static void ModifyGroupName(WordDocument document, string[] mergeGroupNames)
{
   // Iterate through each merge group name.
   foreach (string mergeGroupName in mergeGroupNames)
   {
       // Find the merge field in the document that matches the current group name (Contains begin and end group).
       // The "FieldName" property is used to locate the specific merge field.
       List<Entity> mergeFieldsWithFieldName = document.FindAllItemsByProperty(EntityType.MergeField, "FieldName", mergeGroupName);
       foreach (Entity entity in mergeFieldsWithFieldName)
       {
           WMergeField currentMergeField = entity as WMergeField;
           // You can modify the field name as needed.
           // Example: Modify the field name by appending "_123" to it.
           currentMergeField.FieldName = mergeGroupName + "_123";
       }
   }
}

You can download a complete working sample to change group name of merge fields in the Word document from GitHub.

By executing the program, you will get the Word document as follows.

Conclusion
I hope you enjoyed learning about how to change group name of merge fields in the Word document.

You can refer to our ASP.NET Core DocIO feature tour page to know about its other groundbreaking feature representations and documentation, and how to quickly get started for configuration specifications. You can also explore our ASP.NET Core DocIO example to understand how to create and manipulate data.

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