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如何用 C# 在 .NET 中写入 Excel 文件

Write Excel .NET Functions

Curtis Chau
Curtis Chau
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Many C# application projects require us to update files and write new data in Excel spreadsheets programmatically. Excel .NET capabilities can sometimes be complicated, but using the IronXL library, this task is quite simple and allows working with Excel spreadsheets in any format. No bulk lines of code, just access to the specific cells and the custom values you assign.

Quickstart: Write a Value to a Specific Cell

This example shows how effortlessly you can write a value into a single cell using IronXL and save the Excel file in just a couple of lines—get started without boilerplate or complexity.

Nuget IconGet started making PDFs with NuGet now:

  1. Install IronXL with NuGet Package Manager

    PM > Install-Package IronXL.Excel

  2. Copy and run this code snippet.

    worksheet["A1"].Value = "Hello, IronXL!";
workbook.SaveAs("output.xlsx");

  3. Deploy to test on your live environment

    Start using IronXL in your project today with a free trial
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Write Excel .NET Instructions

  • Download the Library for Excel .NET
  • Write values in specific cells
  • Write static values in multiple cells
  • Write dynamic values in cell range
  • Replace cell values in specific row, column, range, and more
How To Work related to Write Excel .NET Functions

Access Excel Files

Let's start by accessing the Excel file in which we want to write the data. Let's open the Excel file in our project, and then open its specific worksheet using the following code.

:path=/static-assets/excel/content-code-examples/how-to/write-excel-net-load-file.cs
// Load Excel file in the project
WorkBook workBook = WorkBook.Load("path");
' Load Excel file in the project
Dim workBook As WorkBook = WorkBook.Load("path")
$vbLabelText   $csharpLabel

The above will open the specified Excel file. Next, access the worksheet.

:path=/static-assets/excel/content-code-examples/how-to/write-excel-net-get-sheet.cs
// Open Excel WorkSheet
WorkSheet workSheet = workBook.GetWorkSheet("Sheet1");
' Open Excel WorkSheet
Dim workSheet As WorkSheet = workBook.GetWorkSheet("Sheet1")
$vbLabelText   $csharpLabel

The Excel worksheet will open in worksheet and we can use it to write any type of data in the Excel file. Learn more about how to load Excel files and access worksheets in different ways through the examples in the link.

Note: Don't forget to add the reference to IronXL in your project and import the library by using using IronXL.

Write Value in Specific Cell

We can write in an Excel file using many different methods, but the basic approach is using ExcelCell. For this purpose, any cell of the opened Excel worksheet can be accessed and a value written in it as follows:

:path=/static-assets/excel/content-code-examples/how-to/write-excel-net-assign-cell.cs
workSheet["Cell Address"].Value="Assign the Value";
workSheet("Cell Address").Value="Assign the Value"
$vbLabelText   $csharpLabel

Here's an example of how to use the above function to write in an Excel Cell in our C# project.

:path=/static-assets/excel/content-code-examples/how-to/write-excel-net-assign-cell-full.cs
using IronXL;

// Load Excel file
WorkBook workBook = WorkBook.Load("sample.xlsx");

// Open WorkSheet of sample.xlsx
WorkSheet workSheet = workBook.GetWorkSheet("Sheet1");

// Access A1 cell and write the value
workSheet["A1"].Value = "new value";

// Save changes
workBook.SaveAs("sample.xlsx");
Imports IronXL

' Load Excel file
Private workBook As WorkBook = WorkBook.Load("sample.xlsx")

' Open WorkSheet of sample.xlsx
Private workSheet As WorkSheet = workBook.GetWorkSheet("Sheet1")

' Access A1 cell and write the value
Private workSheet("A1").Value = "new value"

' Save changes
workBook.SaveAs("sample.xlsx")
$vbLabelText   $csharpLabel

This code will write new value in cell A1 of the worksheet Sheet1 in the Excel file sample.xlsx. In the same way, we can insert values in any cell address of an Excel file.

Note: Don't forget to save the Excel file after writing new values in the worksheet, as shown in the example above.

Force Assign the Exact Value

When setting the Value property, IronXL will try to convert it to its corresponding value type. Sometimes, this evaluation is undesirable since the user wants to force assign the exact value to the cell without conversion. To do this, assign the value as a string. In IronXL, simply use StringValue instead of Value to achieve the same effect.

:path=/static-assets/excel/content-code-examples/how-to/write-excel-net-assign-stringvalue.cs
// Assign value as string
workSheet["A1"].StringValue = "4402-12";
' Assign value as string
workSheet("A1").StringValue = "4402-12"
$vbLabelText   $csharpLabel

Write Static Values in a Range

We can write new values in multiple cells, called a range, as follows:

// Assign a static value to a range of cells
worksheet["B2:C5"].Value = "static value";
// Assign a static value to a range of cells
worksheet["B2:C5"].Value = "static value";
' Assign a static value to a range of cells
worksheet("B2:C5").Value = "static value"
$vbLabelText   $csharpLabel

In this way, we specify the range of cells From to To where the data will be written. The new value will be written in all the cells which lie in this range. To understand more about C# Excel Range, check out the examples here.

Let's see how to write a range in action using the example below.

:path=/static-assets/excel/content-code-examples/how-to/write-excel-net-assign-cell-range-full.cs
using IronXL;

// Load Excel file
WorkBook workBook = WorkBook.Load("sample.xlsx");

// Open WorkSheet of sample.xlsx
WorkSheet workSheet = workBook.GetWorkSheet("Sheet1");

// Specify range row wise and write new value
workSheet["B2:B9"].Value = "new value";

// Specify range column wise and write new value
workSheet["C3:C7"].Value = "new value";

// Save changes
workBook.SaveAs("sample.xlsx");
Imports IronXL

' Load Excel file
Private workBook As WorkBook = WorkBook.Load("sample.xlsx")

' Open WorkSheet of sample.xlsx
Private workSheet As WorkSheet = workBook.GetWorkSheet("Sheet1")

' Specify range row wise and write new value
Private workSheet("B2:B9").Value = "new value"

' Specify range column wise and write new value
Private workSheet("C3:C7").Value = "new value"

' Save changes
workBook.SaveAs("sample.xlsx")
$vbLabelText   $csharpLabel

This code will write new value from B2 to C5 in the worksheet Sheet1 of the Excel file sample.xlsx. It uses static values for the Excel cells.

Write Dynamic Values in a Range

We can also add dynamic values to a range, as seen below.

:path=/static-assets/excel/content-code-examples/how-to/write-excel-net-assign-dynamic-value.cs
using IronXL;

// Load Excel file
WorkBook workBook = WorkBook.Load("sample.xlsx");

// Open WorkSheet of sample.xlsx
WorkSheet workSheet = workBook.GetWorkSheet("Sheet1");

// Specify range in which we want to write the values
for (int i = 2; i <= 7; i++)
{
    // Write the Dynamic value in one row
    workSheet["B" + i].Value = "Value" + i;

    // Write the Dynamic value in another row
    workSheet["D" + i].Value = "Value" + i;
}

// Save changes
workBook.SaveAs("sample.xlsx");
Imports IronXL

' Load Excel file
Private workBook As WorkBook = WorkBook.Load("sample.xlsx")

' Open WorkSheet of sample.xlsx
Private workSheet As WorkSheet = workBook.GetWorkSheet("Sheet1")

' Specify range in which we want to write the values
For i As Integer = 2 To 7
	' Write the Dynamic value in one row
	workSheet("B" & i).Value = "Value" & i

	' Write the Dynamic value in another row
	workSheet("D" & i).Value = "Value" & i
Next i

' Save changes
workBook.SaveAs("sample.xlsx")
$vbLabelText   $csharpLabel

The above code will write dynamic values in columns B from 2 to 7 in the Excel file sample.xlsx. We can see the result of the code on sample.xlsx.

1excel related to Write Dynamic Values in a Range

Replace Excel Cell Value

Using IronXL, we can easily write a new value to replace the old value, using the Replace() function as follows:

:path=/static-assets/excel/content-code-examples/how-to/write-excel-net-replace.cs
workSheet.Replace("old value", "new value");
workSheet.Replace("old value", "new value")
$vbLabelText   $csharpLabel

The above function will write new value overwriting the old value in the complete Excel worksheet.

Replace Cell Value in Specific Row

If we want to write a new value only in one specific row, do as follows:

:path=/static-assets/excel/content-code-examples/how-to/write-excel-net-replace-row.cs
workSheet.Rows[RowIndex].Replace("old value", "new value");
workSheet.Rows(RowIndex).Replace("old value", "new value")
$vbLabelText   $csharpLabel

This will write new value over the old value in only the specified row index.

Replace Cell Value in Specific Column

Similarly, if we want to write new value over the old value within a specific column, do as follows:

:path=/static-assets/excel/content-code-examples/how-to/write-excel-net-replace-column.cs
workSheet.Columns[ColumnIndex].Replace("old value", "new Value");
workSheet.Columns(ColumnIndex).Replace("old value", "new Value")
$vbLabelText   $csharpLabel

The above code will write new value to replace the old value, but only in the specified column index. The rest of the worksheet remains the same.

Replace Cell Value in Specific Range

IronXL also provides a way to write a new value replacing the old value, only in a specified range.

:path=/static-assets/excel/content-code-examples/how-to/write-excel-net-replace-range.cs
workSheet["From Cell Address : To Cell Address"].Replace("old value", "new value");
workSheet("From Cell Address : To Cell Address").Replace("old value", "new value")
$vbLabelText   $csharpLabel

This will write new value above old value, just in the cells which lie in the specified range.

Let's see the example of how to use all of the above functions to write new values to replace old values in an Excel worksheet.

Example of all Functions

:path=/static-assets/excel/content-code-examples/how-to/write-excel-net-replace-full.cs
using IronXL;

WorkBook workBook = WorkBook.Load("sample.xlsx");
WorkSheet workSheet = workBook.GetWorkSheet("Sheet1");

// Write new above old in complete WorkSheet
workSheet.Replace("old", "new");

// Write new above old just in row no 6 of WorkSheet
workSheet.Rows[5].Replace("old", "new");

// Write new above old just in column no 5 of WorkSheet
workSheet.Columns[4].Replace("old", "new");

// Write new above old just from A5 to H5 of WorkSheet
workSheet["A5:H5"].Replace("old", "new");

workBook.SaveAs("sample.xlsx");
Imports IronXL

Private workBook As WorkBook = WorkBook.Load("sample.xlsx")
Private workSheet As WorkSheet = workBook.GetWorkSheet("Sheet1")

' Write new above old in complete WorkSheet
workSheet.Replace("old", "new")

' Write new above old just in row no 6 of WorkSheet
workSheet.Rows(5).Replace("old", "new")

' Write new above old just in column no 5 of WorkSheet
workSheet.Columns(4).Replace("old", "new")

' Write new above old just from A5 to H5 of WorkSheet
workSheet("A5:H5").Replace("old", "new")

workBook.SaveAs("sample.xlsx")
$vbLabelText   $csharpLabel

For more information about how to write Excel .NET applications and more, check out our full tutorial on how to Open and Write Excel Files C#.

Tutorial Quick Access

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常见问题解答

如何开始在 .NET 中编写 Excel 文件？

要开始使用 IronXL，请下载库并在项目中包含它。在 C# 代码中通过使用 using IronXL 导入库。

如何在 Excel 工作表中的特定单元格中写入值？

要使用 IronXL 在特定单元格中写入值，使用其地址访问单元格，如 worksheet['A1']，然后使用 .Value 属性分配值。

如何在 Excel 中将固定值分配给单元格范围？

要使用 IronXL 将固定值分配给范围，请使用单元格地址指定范围，如 worksheet['B2:C5']，并将 .Value 属性设置为所需的固定值。

我可以在 Excel 中向单元格范围写入动态值吗？

可以，使用 IronXL，您可以通过循环或自定义逻辑向范围写入动态值。例如，您可以迭代单元格地址并根据要求分配动态值。

如何在 Excel 工作表中替换现有单元格值？

使用 IronXL，您可以使用Replace()方法在工作表、行、列或指定范围上将“旧值”替换为“新值”。

使用 Value 和 StringValue 有什么区别？

在 IronXL 中，.Value 属性可能会将分配的值转换为特定类型格式，而 .StringValue 则将值分配为字符串，以避免转换。

如何打开并访问 Excel 文件中的特定工作表？

使用 IronXL 的 WorkBook.Load('path/to/your/excel-file.xlsx') 加载文件，并使用 workbook.GetWorkSheet('SheetName') 访问特定的工作表。

在写入新值后是否有必要保存 Excel 文件？

是的，使用 IronXL 时，在进行更改后必须使用 workbook.SaveAs('filename.xlsx') 方法保存 Excel 文件以持久化更改。

如何写入新值以替换特定行中的旧值？

使用 IronXL，通过 worksheet.Rows[index] 访问行，然后使用旧值和新值调用 Replace() 方法。

我可以替换特定列中的值吗？

是的，使用 IronXL，通过 worksheet.Columns['A'] 访问列，并使用 Replace() 方法将旧值替换为该列中的新值。

如何确保我的 C# 项目可以与 Excel 文件交互？

确保您的 C# 项目引用了 IronXL 库，通过下载它并将其添加到项目的引用中。这样可以促进与 Excel 文件的交互。

在 .NET 中写入 Excel 文件时的一些常见问题是什么？

常见问题包括未正确引用 IronXL 库、单元格地址格式不正确以及忘记保存更改。确保正确设置和语法。

Curtis Chau
Curtis Chau
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技术作家

Curtis Chau 拥有卡尔顿大学的计算机科学学士学位，专注于前端开发，精通 Node.js、TypeScript、JavaScript 和 React。他热衷于打造直观且美观的用户界面，喜欢使用现代框架并创建结构良好、视觉吸引力强的手册。

除了开发之外，Curtis 对物联网 (IoT) 有浓厚的兴趣，探索将硬件和软件集成的新方法。在空闲时间，他喜欢玩游戏和构建 Discord 机器人，将他对技术的热爱与创造力相结合。

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