Dotnet Core Excel Overview

In this modern era, we need a better way to work with Excel Spreadsheets in our .Net Core applications. In the following tutorial, we will learn how to access spreadsheets in dotnet Core Excel projects and modify their values using C#.

Load WorkSheet
using IronXL;
static void Main(string[] args)
{          
    WorkBook wb = WorkBook.Load("sample.xlsx"); //load Excel file 
    WorkSheet ws = wb.GetWorkSheet("Sheet1"); //Get sheet1 of sample.xlsx
    ws["A1"].Value = "new value"; //access A1 cell and edit the value
    wb.SaveAs("sample.xlsx");   //save changes        
}
Imports IronXL
Shared Sub Main(ByVal args() As String)
	Dim wb As WorkBook = WorkBook.Load("sample.xlsx") 'load Excel file
	Dim ws As WorkSheet = wb.GetWorkSheet("Sheet1") 'Get sheet1 of sample.xlsx
	ws("A1").Value = "new value" 'access A1 cell and edit the value
	wb.SaveAs("sample.xlsx") 'save changes
End Sub
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Assign Value Multi Cells
using IronXL;
static void Main(string[] args)
{          
    WorkBook wb = WorkBook.Load("sample.xlsx");
    WorkSheet ws = wb.GetWorkSheet("Sheet1");
    ws["A1:A9"].Value = "new value";
    wb.SaveAs("sample.xlsx");  
}
Imports IronXL
Shared Sub Main(ByVal args() As String)
	Dim wb As WorkBook = WorkBook.Load("sample.xlsx")
	Dim ws As WorkSheet = wb.GetWorkSheet("Sheet1")
	ws("A1:A9").Value = "new value"
	wb.SaveAs("sample.xlsx")
End Sub
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Edit Cells User Input
using IronXL;
static void Main(string[] args)
{
string _from, _to,NewValue ;

Console.Write("Enter Starting Cell :");
_from = Console.ReadLine();

Console.Write("Enter Last Cell :");
_to = Console.ReadLine();

Console.Write("Enter value:");
NewValue = Console.ReadLine();

WorkBook wb = WorkBook.Load("sample.xlsx");
WorkSheet ws = wb.GetWorkSheet("Sheet1");
ws[_from + ":" + _to].Value = NewValue;
wb.SaveAs("sample.xlsx"); 
Console.WriteLine("Successfully Changed...!");
Console.ReadKey();
}
Imports IronXL
Shared Sub Main(ByVal args() As String)
Dim _from, _to, NewValue As String

Console.Write("Enter Starting Cell :")
_from = Console.ReadLine()

Console.Write("Enter Last Cell :")
_to = Console.ReadLine()

Console.Write("Enter value:")
NewValue = Console.ReadLine()

Dim wb As WorkBook = WorkBook.Load("sample.xlsx")
Dim ws As WorkSheet = wb.GetWorkSheet("Sheet1")
ws(_from & ":" & _to).Value = NewValue
wb.SaveAs("sample.xlsx")
Console.WriteLine("Successfully Changed...!")
Console.ReadKey()
End Sub
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Edit Multi Cells Static Value
using IronXL;
static void Main(string[] args)
{
    WorkBook wb = WorkBook.Load("sample.xlsx");
    WorkSheet ws = wb.GetWorkSheet("Sheet1");
    for (int i = From; i <= To; i++) //Set cell range of column A to be edit.
    {
        ws["A" + i].Value = "Value"+i;
    }
    wb.SaveAs("sample.xlsx");  
}
Imports IronXL
Shared Sub Main(ByVal args() As String)
	Dim wb As WorkBook = WorkBook.Load("sample.xlsx")
	Dim ws As WorkSheet = wb.GetWorkSheet("Sheet1")
	For i As Integer = From To [To] 'Set cell range of column A to be edit.
		ws("A" & i).Value = "Value" & i
	Next i
	wb.SaveAs("sample.xlsx")
End Sub
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Try IronXL free for development


Step 1

1. Download IronXL Library

For an easy way to work with Excel files in .NET Core, try IronXL. Download IronXL DLL or install with NuGet for free use in development projects.

 PM > Install-Package IronXL.Excel


How to Tutorial

2. .NET Core Excel Editing Project

Now that you've downloaded IronXL, let's get started. Load an Excel file in the project and access the WorkSheet where data needs to be edited and have changes made.


3. Edit Specific Cell Value

For editing Excel files, add the reference IronXL to your project and import the library by Using IronXL.

3.1. Load a Sample File

In the following case, our Excel file name is sample.xlsx and it exists in the bin> Debug> netcoreapp3.1 folder of the project. We will use this code to edit the value new value in cell A1 of sample.xlsx.

using IronXL;
static void Main(string[] args)
{          
    WorkBook wb = WorkBook.Load("sample.xlsx"); //load Excel file 
    WorkSheet ws = wb.GetWorkSheet("Sheet1"); //Get sheet1 of sample.xlsx
    ws["A1"].Value = "new value"; //access A1 cell and edit the value
    wb.SaveAs("sample.xlsx");   //save changes        
} 
using IronXL;
static void Main(string[] args)
{          
    WorkBook wb = WorkBook.Load("sample.xlsx"); //load Excel file 
    WorkSheet ws = wb.GetWorkSheet("Sheet1"); //Get sheet1 of sample.xlsx
    ws["A1"].Value = "new value"; //access A1 cell and edit the value
    wb.SaveAs("sample.xlsx");   //save changes        
} 
Imports IronXL
Shared Sub Main(ByVal args() As String)
	Dim wb As WorkBook = WorkBook.Load("sample.xlsx") 'load Excel file
	Dim ws As WorkSheet = wb.GetWorkSheet("Sheet1") 'Get sheet1 of sample.xlsx
	ws("A1").Value = "new value" 'access A1 cell and edit the value
	wb.SaveAs("sample.xlsx") 'save changes
End Sub
VB   C#


4. Assign Value to Multiple Cells

It is very easy to edit multiple cells and assign static value at a time by using (colon :). Its left side indicates starting cell, and the right side indicates the last cell of a specific column.

sheet[From:To]

This will edit new value from cell A1 to A9 of column A.

using IronXL;
static void Main(string[] args)
{          
    WorkBook wb = WorkBook.Load("sample.xlsx");
    WorkSheet ws = wb.GetWorkSheet("Sheet1");
    ws["A1:A9"].Value = "new value";
    wb.SaveAs("sample.xlsx");  
}          
using IronXL;
static void Main(string[] args)
{          
    WorkBook wb = WorkBook.Load("sample.xlsx");
    WorkSheet ws = wb.GetWorkSheet("Sheet1");
    ws["A1:A9"].Value = "new value";
    wb.SaveAs("sample.xlsx");  
}          
Imports IronXL
Shared Sub Main(ByVal args() As String)
	Dim wb As WorkBook = WorkBook.Load("sample.xlsx")
	Dim ws As WorkSheet = wb.GetWorkSheet("Sheet1")
	ws("A1:A9").Value = "new value"
	wb.SaveAs("sample.xlsx")
End Sub
VB   C#


5. Edit Cells with User Inputs

Here is an alternative case where we can take the values from the users and edit the Excel file.

using IronXL;
static void Main(string[] args)
{
string _from, _to,NewValue ;

Console.Write("Enter Starting Cell :");
_from = Console.ReadLine();

Console.Write("Enter Last Cell :");
_to = Console.ReadLine();

Console.Write("Enter value:");
NewValue = Console.ReadLine();

WorkBook wb = WorkBook.Load("sample.xlsx");
WorkSheet ws = wb.GetWorkSheet("Sheet1");
ws[_from + ":" + _to].Value = NewValue;
wb.SaveAs("sample.xlsx"); 
Console.WriteLine("Successfully Changed...!");
Console.ReadKey();
}
using IronXL;
static void Main(string[] args)
{
string _from, _to,NewValue ;

Console.Write("Enter Starting Cell :");
_from = Console.ReadLine();

Console.Write("Enter Last Cell :");
_to = Console.ReadLine();

Console.Write("Enter value:");
NewValue = Console.ReadLine();

WorkBook wb = WorkBook.Load("sample.xlsx");
WorkSheet ws = wb.GetWorkSheet("Sheet1");
ws[_from + ":" + _to].Value = NewValue;
wb.SaveAs("sample.xlsx"); 
Console.WriteLine("Successfully Changed...!");
Console.ReadKey();
}
Imports IronXL
Shared Sub Main(ByVal args() As String)
Dim _from, _to, NewValue As String

Console.Write("Enter Starting Cell :")
_from = Console.ReadLine()

Console.Write("Enter Last Cell :")
_to = Console.ReadLine()

Console.Write("Enter value:")
NewValue = Console.ReadLine()

Dim wb As WorkBook = WorkBook.Load("sample.xlsx")
Dim ws As WorkSheet = wb.GetWorkSheet("Sheet1")
ws(_from & ":" & _to).Value = NewValue
wb.SaveAs("sample.xlsx")
Console.WriteLine("Successfully Changed...!")
Console.ReadKey()
End Sub
VB   C#

The above code will display the following output and take inputs from user:

Values changed from B4 to B9 in ExcelSheet, we can see:


6. Edit Multiple Cells with Static Value

It is very easy to edit multiple cells and assign dynamic values. Let's see the following example:

using IronXL;
static void Main(string[] args)
{
    WorkBook wb = WorkBook.Load("sample.xlsx");
    WorkSheet ws = wb.GetWorkSheet("Sheet1");
    for (int i = From; i <= To; i++) //Set cell range of column A to be edit.
    {
        ws["A" + i].Value = "Value"+i;
    }
    wb.SaveAs("sample.xlsx");  
}
using IronXL;
static void Main(string[] args)
{
    WorkBook wb = WorkBook.Load("sample.xlsx");
    WorkSheet ws = wb.GetWorkSheet("Sheet1");
    for (int i = From; i <= To; i++) //Set cell range of column A to be edit.
    {
        ws["A" + i].Value = "Value"+i;
    }
    wb.SaveAs("sample.xlsx");  
}
Imports IronXL
Shared Sub Main(ByVal args() As String)
	Dim wb As WorkBook = WorkBook.Load("sample.xlsx")
	Dim ws As WorkSheet = wb.GetWorkSheet("Sheet1")
	For i As Integer = From To [To] 'Set cell range of column A to be edit.
		ws("A" & i).Value = "Value" & i
	Next i
	wb.SaveAs("sample.xlsx")
End Sub
VB   C#


7. Read Excel Files In-Depth Tutorial

Dive in with further details and multiple projects and code examples if you want to learn more about how to Read Excel Files C# with this tutorial.


Tutorial Quick Access

Investigate the Object Reference

Documentation is provided for IronXL, featuring all namespaces, feature sets, methods fields, classes, and enums.

Object Reference