How to apply multiple colors to a single merge field in a 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 apply multiple colors to a single merge field in a Word document using C#.

To achieve this, split the field value and apply separate colors to each part using the MergeField event.

Steps to apply multiple colors to a single merge field in a 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.DLS;
using Syncfusion.DocIO; 

4. Use the following code example to apply multiple colors to a single merge field in a Word document.
   C#

using (FileStream fileStream = new FileStream(Path.GetFullPath(@"Data/Template.docx"), FileMode.Open, FileAccess.ReadWrite))
{
   //Loads an existing Word document into DocIO instance.
   using (WordDocument document = new WordDocument(fileStream, FormatType.Automatic))
   {
       string[] fieldNames = new string[] { "RedBlack", "RedBlackGreen" };
       string[] fieldValues = new string[] { "Red Black", "Red Black Green" };
       //Creates mail merge events handler to split the field value and applies the color
       document.MailMerge.MergeField += new MergeFieldEventHandler(MergeFieldEvent);
       //Performs the mail merge
       document.MailMerge.Execute(fieldNames, fieldValues);
       //Removes mail merge events handler
       document.MailMerge.MergeField -= new MergeFieldEventHandler(MergeFieldEvent);

       //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 code example to splits the field value and applies the color by using MergeFieldEventHandler.
   C#

public static void MergeFieldEvent(object sender, MergeFieldEventArgs args)
{
   if (args.FieldName == "RedBlack" || args.FieldName == "RedBlackGreen")
   {
       //Split the field result value based on space between the words.
       string[] splitText = args.FieldValue.ToString().Split(' ');

       //Modifies the field result text as "Red" and applies the color red.
       args.TextRange.Text = splitText[0];
       if (args.TextRange.Text == "Red")
           args.TextRange.CharacterFormat.TextColor = Color.Red;

       //Gets the merge field owner paragraph.
       WParagraph paragraph = args.CurrentMergeField.OwnerParagraph;
       //Gets the index of merge field
       int fieldIndex = paragraph.ChildEntities.IndexOf(args.CurrentMergeField);
       //Gets the index next to the merge field.
       int fieldNextIndex = GetFieldNextIndex(fieldIndex, paragraph);

       //Appends the remaining texts after the merge field and applies the color.
       for (int i = 1; i < splitText.Length; i++)
       {
           //Initialize new text range.
           WTextRange textRange = new WTextRange(paragraph.Document);
           //Specifies the text.
           textRange.Text = " " + splitText[i];
           //Applies the color based on the text
           if (textRange.Text == " " + "Black")
               textRange.CharacterFormat.TextColor = Color.Black;
           else if (textRange.Text == " " + "Green")
               textRange.CharacterFormat.TextColor = Color.Green;

           //Appends the text range after the merge field.
           if (fieldNextIndex != -1 && fieldNextIndex < paragraph.ChildEntities.Count)
               paragraph.ChildEntities.Insert(fieldNextIndex, textRange);
           else
               paragraph.ChildEntities.Add(textRange);
           fieldNextIndex++;
       }
   }
} 

6. Use the following code example to get the index next to the merge field.
   C#

public static int GetFieldNextIndex(int fieldIndex, WParagraph paragraph)
{
    for (int i = fieldIndex; i < paragraph.ChildEntities.Count; i++)
    {
        ParagraphItem item = paragraph.ChildEntities[i] as ParagraphItem;
        if (item != null && item is WFieldMark && (item as WFieldMark).Type == FieldMarkType.FieldEnd)
            return i + 1;
    }
    return -1;
} 

You can download a complete working sample to apply multiple colors to a single merge field in a Word document from the GitHub.

Take a moment to peruse the documentation where you can find basic Word document processing options along with the features like mail merge, merge, split, and compare Word documents, find and replace text in the Word document, protect the Word documents, and most importantly, the PDF and Image conversions with code examples.

See Also

• Mail merge events

Conclusion

I hope you enjoyed learning about how to apply multiple colors to a single merge field in a Word document in .NET Core 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.

For current customers, you can check out our components from the License and Downloads page. If you are new to Syncfusion®, you can try our 30-day free trial to check out our other controls.

If you have any queries or require clarifications, please let us know in the comments section below. You can also contact us through our support forums, Direct-Trac, or feedback portal. We are always happy to assist you!