Read a CSV File in C#

Updated: 2026年6月4日

IronXL提供了一行程式碼來使用LoadCSV方法讀取C#中的CSV文件。它支持自定義分隔符並直接轉換為Excel格式，以便在.NET應用程式中無縫處理資料。

快速入門：使用IronXL在一行中載入並轉換CSV文件

此範例顯示如何使用IronXL的LoadCSV方法讀取CSV文件並以最少的程式碼將其保存為Excel工作簿。

1Install IronXL with NuGet Package Manager
PM > Install-Package IronXL.Excel
```
Install-Package IronXL.Excel
```

2複製並運行這段程式碼片段。

WorkBook wb = WorkBook.LoadCSV("data.csv", ExcelFileFormat.XLSX, listDelimiter: ","); wb.SaveAs("output.xlsx");

WorkBook wb = WorkBook.LoadCSV("data.csv", ExcelFileFormat.XLSX, listDelimiter: ","); wb.SaveAs("output.xlsx");

3部署以在您的實時環境中測試

今天就開始在您的專案中使用IronXL，透過免費試用

最小工作流（5步）

下載並安裝C# CSV讀取程式庫
建立一個C#或VB專案
將此頁面的程式碼範例新增到您的專案中
指定CSV路徑和輸出名稱&格式
運行專案以查看文件

在.NET應用程式中讀取CSV文件

安裝一個C#程式庫來讀取CSV文件（IronXL）
在C#中讀取CSV文件
指定文件格式和分隔符

第1步

如何安裝IronXL程式庫？

在使用IronXL在MVC、ASP或.NET Core中讀取CSV文件之前，您需要安裝它。這裡有一個快速指南。

為什麼我應該使用NuGet Package Manager？

在Visual Studio中，選擇專案選單
管理NuGet包
搜索IronXL.Excel
安裝

Visual Studio NuGet包管理器正在安裝IronXL.Excel程式庫，帶有包詳細資訊和控制台輸出

Figure 1

IronXL.Excel NuGet Package

有哪些替代安裝方法？

Or download from the Iron Software website: https://ironsoftware.com/csharp/excel/packages/IronXL.zip

對於使用Docker容器進行工作的.NET開發人員，IronXL可在您的Docker環境中配置。該程式庫還支持在Azure Functions和AWS Lambda上部署以進行基於雲的CSV處理。

教程指南

我如何以程式化方式讀取CSV文件？

現在該進入專案了！

我需要導入什麼名稱空間？

新增IronXL名稱空間：

// This namespace is required to access the IronXL functionalities
using IronXL;

// This namespace is required to access the IronXL functionalities
using IronXL;

Imports IronXL

Imports IronXL

如何載入並轉換CSV文件？

新增程式碼以使用IronXL和C#以程式化方式讀取CSV文件：

// Load the CSV file into a WorkBook object, specifying the file path, format, and delimiter
WorkBook workbook = WorkBook.LoadCSV("Read_CSV_Ex.csv", fileFormat: ExcelFileFormat.XLSX, listDelimiter: ",");

// Access the default worksheet within the loaded workbook
WorkSheet ws = workbook.DefaultWorkSheet;

// Save the workbook as an Excel file with a specified name
workbook.SaveAs("Csv_To_Excel.xlsx");

// Load the CSV file into a WorkBook object, specifying the file path, format, and delimiter
WorkBook workbook = WorkBook.LoadCSV("Read_CSV_Ex.csv", fileFormat: ExcelFileFormat.XLSX, listDelimiter: ",");

// Access the default worksheet within the loaded workbook
WorkSheet ws = workbook.DefaultWorkSheet;

// Save the workbook as an Excel file with a specified name
workbook.SaveAs("Csv_To_Excel.xlsx");

' Load the CSV file into a WorkBook object, specifying the file path, format, and delimiter
Dim workbook As WorkBook = WorkBook.LoadCSV("Read_CSV_Ex.csv", fileFormat:=ExcelFileFormat.XLSX, listDelimiter:=",")

' Access the default worksheet within the loaded workbook
Dim ws As WorkSheet = workbook.DefaultWorkSheet

' Save the workbook as an Excel file with a specified name
workbook.SaveAs("Csv_To_Excel.xlsx")

' Load the CSV file into a WorkBook object, specifying the file path, format, and delimiter
Dim workbook As WorkBook = WorkBook.LoadCSV("Read_CSV_Ex.csv", fileFormat:=ExcelFileFormat.XLSX, listDelimiter:=",")

' Access the default worksheet within the loaded workbook
Dim ws As WorkSheet = workbook.DefaultWorkSheet

' Save the workbook as an Excel file with a specified name
workbook.SaveAs("Csv_To_Excel.xlsx")

有哪些進階CSV讀取選項可用？

IronXL提供了一些功能來處理具有多種配置的CSV文件。您可以指定不同的分隔符（分號、制表符、管道符）並處理具有不同編碼的文件：

// Example: Reading CSV with custom delimiter
WorkBook workbook = WorkBook.LoadCSV("data.csv",
    fileFormat: ExcelFileFormat.XLSX,
    listDelimiter: ";");  // Using semicolon as delimiter

// Access specific cells after loading
var cellValue = workbook.DefaultWorkSheet["A1"].Value;

// Iterate through rows
foreach (var row in workbook.DefaultWorkSheet.Rows)
{
    // Process each row
    foreach (var cell in row)
    {
        Console.WriteLine(cell.Value);
    }
}

// Example: Reading CSV with custom delimiter
WorkBook workbook = WorkBook.LoadCSV("data.csv",
    fileFormat: ExcelFileFormat.XLSX,
    listDelimiter: ";");  // Using semicolon as delimiter

// Access specific cells after loading
var cellValue = workbook.DefaultWorkSheet["A1"].Value;

// Iterate through rows
foreach (var row in workbook.DefaultWorkSheet.Rows)
{
    // Process each row
    foreach (var cell in row)
    {
        Console.WriteLine(cell.Value);
    }
}

在處理之前CSV文件看起來怎麼樣？

記事本中的CSV文件顯示動物資料，包括月份、長頸鹿、大象、犀牛欄以及6個月的資料

Figure 2

A CSV file opened in Notepad

LoadCSV方法如何運作？

建立一個Workbook物件。 Workbook物件指定要讀取的CSV文件、要讀取的格式和分隔符。在這種情況下，逗號用作分隔符。

建立一個Worksheet物件，放置CSV內容。然後將文件保存為新名稱和格式。當您需要在不同的試算表格式之間轉換時，此過程非常有用。

Excel試算表顯示CSV資料，包含月份、長頸鹿、大象和犀牛欄以及6個月的動物數量資料

Figure 3

The CSV file opened in Excel

我可以有效地處理大型CSV文件嗎？

IronXL針對性能進行了優化，有效地處理大型CSV文件。對於處理大量資料集的開發人員，該程式庫在近期版本中提供了顯著的性能提升。處理大文件時，請考慮這些最佳實踐：

// Reading large CSV files with memory optimization
WorkBook workbook = WorkBook.LoadCSV("large_dataset.csv", 
    fileFormat: ExcelFileFormat.XLSX, 
    listDelimiter: ",");

// Process data in chunks
var worksheet = workbook.DefaultWorkSheet;
int rowCount = worksheet.RowCount;
int batchSize = 1000;

for (int i = 0; i < rowCount; i += batchSize)
{
    // Process rows in batches
    var endIndex = Math.Min(i + batchSize, rowCount);
    for (int j = i; j < endIndex; j++)
    {
        var row = worksheet.GetRow(j);
        // Process individual row
    }
}

// Reading large CSV files with memory optimization
WorkBook workbook = WorkBook.LoadCSV("large_dataset.csv", 
    fileFormat: ExcelFileFormat.XLSX, 
    listDelimiter: ",");

// Process data in chunks
var worksheet = workbook.DefaultWorkSheet;
int rowCount = worksheet.RowCount;
int batchSize = 1000;

for (int i = 0; i < rowCount; i += batchSize)
{
    // Process rows in batches
    var endIndex = Math.Min(i + batchSize, rowCount);
    for (int j = i; j < endIndex; j++)
    {
        var row = worksheet.GetRow(j);
        // Process individual row
    }
}

Imports System
Imports IronXL

' Reading large CSV files with memory optimization
Dim workbook As WorkBook = WorkBook.LoadCSV("large_dataset.csv", 
                                            fileFormat:=ExcelFileFormat.XLSX, 
                                            listDelimiter:=",")

' Process data in chunks
Dim worksheet = workbook.DefaultWorkSheet
Dim rowCount As Integer = worksheet.RowCount
Dim batchSize As Integer = 1000

For i As Integer = 0 To rowCount - 1 Step batchSize
    ' Process rows in batches
    Dim endIndex As Integer = Math.Min(i + batchSize, rowCount)
    For j As Integer = i To endIndex - 1
        Dim row = worksheet.GetRow(j)
        ' Process individual row
    Next
Next

Imports System
Imports IronXL

' Reading large CSV files with memory optimization
Dim workbook As WorkBook = WorkBook.LoadCSV("large_dataset.csv", 
                                            fileFormat:=ExcelFileFormat.XLSX, 
                                            listDelimiter:=",")

' Process data in chunks
Dim worksheet = workbook.DefaultWorkSheet
Dim rowCount As Integer = worksheet.RowCount
Dim batchSize As Integer = 1000

For i As Integer = 0 To rowCount - 1 Step batchSize
    ' Process rows in batches
    Dim endIndex As Integer = Math.Min(i + batchSize, rowCount)
    For j As Integer = i To endIndex - 1
        Dim row = worksheet.GetRow(j)
        ' Process individual row
    Next
Next

我如何將CSV資料導出到其他格式？

讀取CSV文件後，您可能需要將資料導出到多種格式。 IronXL支持多種導出選項，包括XLSX到CSV轉換、JSON、XML和HTML。以下是如何導出到不同格式：

// Load CSV and export to multiple formats
WorkBook workbook = WorkBook.LoadCSV("input.csv", ExcelFileFormat.XLSX, ",");

// Export to different formats
workbook.SaveAs("output.xlsx"); // Excel format
workbook.SaveAsJson("output.json"); // JSON format
workbook.SaveAsXml("output.xml"); // XML format

// Export specific worksheet to CSV with custom delimiter
workbook.DefaultWorkSheet.SaveAsCsv("output_custom.csv", ";");

// Load CSV and export to multiple formats
WorkBook workbook = WorkBook.LoadCSV("input.csv", ExcelFileFormat.XLSX, ",");

// Export to different formats
workbook.SaveAs("output.xlsx"); // Excel format
workbook.SaveAsJson("output.json"); // JSON format
workbook.SaveAsXml("output.xml"); // XML format

// Export specific worksheet to CSV with custom delimiter
workbook.DefaultWorkSheet.SaveAsCsv("output_custom.csv", ";");

在Web應用程式中處理CSV資料如何？

對於ASP.NET開發人員，IronXL提供在Web應用程式中讀取CSV文件的無縫整合。您可以在您的MVC或Web API專案中上傳並處理CSV文件：

// Example: Processing uploaded CSV file in ASP.NET
public ActionResult UploadCSV(HttpPostedFileBase file)
{
    if (file != null && file.ContentLength > 0)
    {
        // Save uploaded file temporarily
        var fileName = Path.GetFileName(file.FileName);
        var path = Path.Combine(Server.MapPath("~/App_Data/"), fileName);
        file.SaveAs(path);
        
        // Load and process CSV
        WorkBook workbook = WorkBook.LoadCSV(path, ExcelFileFormat.XLSX, ",");
        
        // Convert to DataTable for easy display
        var dataTable = workbook.DefaultWorkSheet.ToDataTable();
        
        // Clean up temporary file
        System.IO.File.Delete(path);
        
        return View(dataTable);
    }
    return RedirectToAction("Index");
}

// Example: Processing uploaded CSV file in ASP.NET
public ActionResult UploadCSV(HttpPostedFileBase file)
{
    if (file != null && file.ContentLength > 0)
    {
        // Save uploaded file temporarily
        var fileName = Path.GetFileName(file.FileName);
        var path = Path.Combine(Server.MapPath("~/App_Data/"), fileName);
        file.SaveAs(path);
        
        // Load and process CSV
        WorkBook workbook = WorkBook.LoadCSV(path, ExcelFileFormat.XLSX, ",");
        
        // Convert to DataTable for easy display
        var dataTable = workbook.DefaultWorkSheet.ToDataTable();
        
        // Clean up temporary file
        System.IO.File.Delete(path);
        
        return View(dataTable);
    }
    return RedirectToAction("Index");
}

' Example: Processing uploaded CSV file in ASP.NET
Public Function UploadCSV(file As HttpPostedFileBase) As ActionResult
    If file IsNot Nothing AndAlso file.ContentLength > 0 Then
        ' Save uploaded file temporarily
        Dim fileName = Path.GetFileName(file.FileName)
        Dim path = Path.Combine(Server.MapPath("~/App_Data/"), fileName)
        file.SaveAs(path)
        
        ' Load and process CSV
        Dim workbook As WorkBook = WorkBook.LoadCSV(path, ExcelFileFormat.XLSX, ",")
        
        ' Convert to DataTable for easy display
        Dim dataTable = workbook.DefaultWorkSheet.ToDataTable()
        
        ' Clean up temporary file
        System.IO.File.Delete(path)
        
        Return View(dataTable)
    End If
    Return RedirectToAction("Index")
End Function

' Example: Processing uploaded CSV file in ASP.NET
Public Function UploadCSV(file As HttpPostedFileBase) As ActionResult
    If file IsNot Nothing AndAlso file.ContentLength > 0 Then
        ' Save uploaded file temporarily
        Dim fileName = Path.GetFileName(file.FileName)
        Dim path = Path.Combine(Server.MapPath("~/App_Data/"), fileName)
        file.SaveAs(path)
        
        ' Load and process CSV
        Dim workbook As WorkBook = WorkBook.LoadCSV(path, ExcelFileFormat.XLSX, ",")
        
        ' Convert to DataTable for easy display
        Dim dataTable = workbook.DefaultWorkSheet.ToDataTable()
        
        ' Clean up temporary file
        System.IO.File.Delete(path)
        
        Return View(dataTable)
    End If
    Return RedirectToAction("Index")
End Function

我如何處理具有複雜資料的CSV文件？

處理包含公式、特殊字元或混合資料型別的CSV文件時，IronXL提供了強大的處理能力。您可以處理公式，並適當地格式化單元格資料：

// Handle CSV with special requirements
WorkBook workbook = WorkBook.LoadCSV("complex_data.csv", 
    ExcelFileFormat.XLSX, 
    listDelimiter: ",");

var worksheet = workbook.DefaultWorkSheet;

// Apply formatting to cells
worksheet["A1:A10"].Style.Font.Bold = true;
worksheet["B1:B10"].FormatString = "$#,##0.00"; // Currency format

// Add formulas after loading CSV data
worksheet["D1"].Formula = "=SUM(B1:B10)";

// Handle CSV with special requirements
WorkBook workbook = WorkBook.LoadCSV("complex_data.csv", 
    ExcelFileFormat.XLSX, 
    listDelimiter: ",");

var worksheet = workbook.DefaultWorkSheet;

// Apply formatting to cells
worksheet["A1:A10"].Style.Font.Bold = true;
worksheet["B1:B10"].FormatString = "$#,##0.00"; // Currency format

// Add formulas after loading CSV data
worksheet["D1"].Formula = "=SUM(B1:B10)";

Imports IronXL

' Handle CSV with special requirements
Dim workbook As WorkBook = WorkBook.LoadCSV("complex_data.csv", ExcelFileFormat.XLSX, listDelimiter:=",")

Dim worksheet = workbook.DefaultWorkSheet

' Apply formatting to cells
worksheet("A1:A10").Style.Font.Bold = True
worksheet("B1:B10").FormatString = "$#,##0.00" ' Currency format

' Add formulas after loading CSV data
worksheet("D1").Formula = "=SUM(B1:B10)"

Imports IronXL

' Handle CSV with special requirements
Dim workbook As WorkBook = WorkBook.LoadCSV("complex_data.csv", ExcelFileFormat.XLSX, listDelimiter:=",")

Dim worksheet = workbook.DefaultWorkSheet

' Apply formatting to cells
worksheet("A1:A10").Style.Font.Bold = True
worksheet("B1:B10").FormatString = "$#,##0.00" ' Currency format

' Add formulas after loading CSV data
worksheet("D1").Formula = "=SUM(B1:B10)"

程式庫快速存取

IronXL API參考文件

了解更多並分享如何合併、取消合併和使用IronXL API參考文件處理Excel試算表中的單元格。

IronXL API參考文件

常見問題

如何快速使用 C# 讀取 CSV 檔案？

IronXL 提供一行解決方案來使用 C# 讀取 CSV 檔案，使用 LoadCSV 方法。簡單使用：WorkBook wb = WorkBook.LoadCSV("data.csv", ExcelFileFormat.XLSX, listDelimiter: ","); 這樣便載入您的 CSV 檔案，並允許您將其保存為 Excel 活頁簿，使用 wb.SaveAs("output.xlsx")。

有哪些安裝方法可用於 CSV 讀取程式庫？

您可以通過 Visual Studio 的 NuGet Package Manager 安裝 IronXL，搜索 'IronXL.Excel'，或直接從 Iron Software 網站下載。該程式庫還支持 Docker 容器、Azure Functions 和 AWS Lambda 用於基於雲端的 CSV 處理。