Write to existing Excel in C#, VB.NET
Syncfusion Excel (XlsIO) library is a .NET Excel library used to create, read, and edit Excel documents. Using this library, you can write data into an existing Excel worksheet in C# and VB.NET.
Steps to write data into an Excel file programmatically:
Step 1: Create a new C# console application project.
Create a new C# console application
Step 2: Install Syncfusion.XlsIO.WinForms NuGet package as a reference to your .NET Framework applications from the NuGet.org.
Install NuGet package
Step 3: Include the following namespaces in the Program.cs file.
C#
using Syncfusion.XlsIO; using System.IO; using System.Reflection;
VB.NET
Imports Syncfusion.XlsIO Imports System.IO Imports System.Reflection
Step 4: Add the following code snippet to write data into an existing Excel file.
C#
//Create an instance of ExcelEngine using (ExcelEngine excelEngine = new ExcelEngine()) { //Set the default application version as Excel 2016 excelEngine.Excel.DefaultVersion = ExcelVersion.Excel2016; //Open existing workbook with data entered Assembly assembly = typeof(Program).GetTypeInfo().Assembly; Stream fileStream = assembly.GetManifestResourceStream("WriteData.Sample.xlsx"); IWorkbook workbook = application.Workbooks.Open(fileStream); //Access first worksheet from the workbook instance IWorksheet worksheet = workbook.Worksheets[0]; //Insert sample text into cell “A1” worksheet.Range["A1"].Text = "Syncfusion Essential XlsIO"; //Save the workbook to disk in xlsx format workbook.SaveAs("Output.xlsx"); }
VB.NET
'Create an instance of ExcelEngine Using excelEngine As ExcelEngine = New ExcelEngine 'Set the default application version as Excel 2016 excelEngine.Excel.DefaultVersion = ExcelVersion.Excel2016 'Open an existing workbook with data entered Dim assembly As Assembly = GetType(Program).GetTypeInfo.Assembly Dim fileStream As Stream = assembly.GetManifestResourceStream("WriteData.Sample.xlsx") Dim workbook As IWorkbook = application.Workbooks.Open(fileStream) 'Access first worksheet from the workbook instance Dim worksheet As IWorksheet = workbook.Worksheets(0) 'Insert sample text into cell “A1” worksheet.Range("A1").Text = "Syncfusion Essential XlsIO" 'Save the workbook to disk in xlsx format workbook.SaveAs("Output.xlsx") End Using
A complete working example to write data to an existing Excel file along with input file used can be downloaded from Write Data to Existing Excel file.zip
By executing the program, you will get the output Excel file as shown below.
Output Excel document
Take a moment to peruse the documentation, where you can find basic worksheet data manipulation options along with features like Conditional Formatting, worksheet calculations through Formulas, adding Charts in worksheet or workbook, organizing and analyzing data through Tables and Pivot Tables, appending multiple records to worksheet using Template Markers, and most importantly PDF and Image conversions with code examples.
Refer here to explore the rich set of Syncfusion Excel (XlsIO) library features.
An online sample link to generate Excel file.
See Also:
Read Excel from Code in C#, VB.NET
Starting with v16.2.0.x, if you reference Syncfusion assemblies from trial setup or from the NuGet feed, include a license key in your projects. Refer the link to learn about generating and registering Syncfusion license key in your application to use the components without trail message.