Word Document Generation with Mail Merge in C#

Wordize for .NET is a professional solution for automated creation of personalized Word documents using Mail Merge technology. The MailMerger class enables C# developers to merge ready-made document templates with data from various sources for bulk generation of personalized Word invoices, contracts, reports, and letters.

Wordize for .NET provides the ability to use Mail Merge technology with templates in any supported formats. This allows creating personalized Word documents regardless of the original template format.

Functional Capabilities:

Simple document population - the Execute() method generates personalized Word documents by merging ready-made templates with external data sources
Dynamic content generation - the ExecuteWithRegions() method processes repeating template elements to create tables and lists of variable length in Word format
Integration with various data sources - support for DataRow, DataTable, DataSet types, value arrays
Advanced settings - the MailMergeOptions class manages document generation parameters: removing empty paragraphs, unused regions and fields, trimming excess spaces, merging duplicate regions, and other parameters
Export to graphic format capability - the ExecuteToImages() method returns results as a set of images
Fluent API support for launching generation through MailMergerContext and method chaining, adding clarity to C# code

Use Case Scenarios:

Bulk mailing of personalized letters and notifications with individual recipient data
Creating personalized Word invoices, contracts, and proposals with information specific to each client
Generating Word documents from ready-made forms: certificates, references, invitations with personal data
Automated creation of uniform Word documents with different content based on databases

Test the capabilities of programmatic generation of personalized documents using Mail Merge technology in the interactive online demo presented on this page. Upload a document template, a text file with data (CSV, JSON, XML), run the operation, and download the generated result for verification. The provided C# code snippet is fully ready for use in your .NET project.

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Upload document template

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Select output format from the list

 
				
				
		
using System.Data;
using Newtonsoft.Json;
using Wordize.MailMerging;

string json = File.ReadAllText("DataSource.json");
DataTable dataTable = JsonConvert.DeserializeObject(json);
MailMerger.Execute("Input.docx", "Output.docx", SaveFormat.Docx, dataTable);

										using System.Data;
using Newtonsoft.Json;
using Wordize.MailMerging;

string json = File.ReadAllText("DataSource.json");
DataTable dataTable = JsonConvert.DeserializeObject(json);
MailMerger.Execute("Input.docx", "Output.docx", SaveFormat.Docx, dataTable);

										using System.Data;
using Newtonsoft.Json;
using Wordize.MailMerging;
using Wordize.Saving;

string json = File.ReadAllText("DataSource.json");
DataTable dataTable = JsonConvert.DeserializeObject(json);
var imageStreams = MailMerger.Execute("Input.docx", new ImageSaveOptions(SaveFormat.Docx),  dataTable);

foreach (var (stream, page) in imageStreams.Select((s, i) => (s, i)))
{
    using var _ = stream;
    stream.Position = 0;
    
    using var file = File.Create($"Output_{page + 1}.docx");
    stream.CopyTo(file);
}

					
using System.Data;
using Wordize.MailMerging;

DataSet dataSet = new DataSet();
dataSet.ReadXml("DataSource.xml");
MailMerger.Execute("Input.docx", "Output.docx", SaveFormat.Docx, dataSet.Tables[0]);

										using System.Data;
using Wordize.MailMerging;

DataSet dataSet = new DataSet();
dataSet.ReadXml("DataSource.xml");
MailMerger.Execute("Input.docx", "Output.docx", SaveFormat.Docx, dataSet.Tables[0]);

										using System.Data;
using Wordize.MailMerging;
using Wordize.Saving;

DataSet dataSet = new DataSet();
dataSet.ReadXml("DataSource.xml");
var imageStreams = MailMerger.Execute("Input.docx", new ImageSaveOptions(SaveFormat.Docx),  dataSet.Tables[0]);

foreach (var (stream, page) in imageStreams.Select((s, i) => (s, i)))
{
    using var _ = stream;
    stream.Position = 0;
    
    using var file = File.Create($"Output_{page + 1}.docx");
    stream.CopyTo(file);
}

					

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How to generate Word files in C#

Connect the Wordize SDK to your .NET project
Read the data file, deserialize it into DataTable and call Execute(), specifying the Word template, output file, save format and data source
Get the generated Word documents