How to Read CSV File in C# - Simple Guide

To read a CSV file in C#, use System.IO.File.ReadAllLines to get all lines, then split each line by commas with string.Split(','). This lets you process each row and column easily in your program.

Syntax

Use File.ReadAllLines(path) to read all lines from a CSV file into a string array. Then, use line.Split(',') to separate each line into columns.

• path: The file path to your CSV file.
• ReadAllLines: Reads all lines at once.
• Split: Divides each line into parts by commas.

csharp

string[] lines = File.ReadAllLines("file.csv");
foreach (string line in lines)
{
    string[] columns = line.Split(',');
    // Process columns
}

Example

This example reads a CSV file named data.csv with two columns: Name and Age. It prints each row's values to the console.

csharp

using System;
using System.IO;

class Program
{
    static void Main()
    {
        string path = "data.csv";
        string[] lines = File.ReadAllLines(path);

        foreach (string line in lines)
        {
            string[] columns = line.Split(',');
            string name = columns[0];
            string age = columns[1];
            Console.WriteLine($"Name: {name}, Age: {age}");
        }
    }
}

Output

Name: Alice, Age: 30
Name: Bob, Age: 25
Name: Charlie, Age: 35

Common Pitfalls

Common mistakes when reading CSV files include:

• Not handling empty lines or missing columns, which can cause errors.
• Assuming commas are the only separator; some CSVs use semicolons or tabs.
• Not trimming spaces around values, leading to unexpected whitespace.
• Ignoring quoted fields that contain commas inside them.

For simple CSVs, Split(',') works, but for complex files, consider using a CSV parsing library.

csharp

/* Wrong way: Not checking columns length */
string[] columns = line.Split(',');
string name = columns[0];
string age = columns[1]; // May throw error if columns missing

/* Right way: Check columns length */
string[] columns = line.Split(',');
if (columns.Length >= 2)
{
    string name = columns[0].Trim();
    string age = columns[1].Trim();
    // Use values safely
}

Quick Reference

Tips for reading CSV files in C#:

• Use File.ReadAllLines for small files.
• Use Split(',') to separate columns.
• Trim values to remove extra spaces.
• Check array length before accessing columns.
• For complex CSVs, use libraries like CsvHelper.

Key Takeaways

Use File.ReadAllLines to read all lines from a CSV file at once.

Split each line by commas to get individual columns.

Always check the number of columns before accessing to avoid errors.

Trim column values to clean extra spaces.

For complex CSV formats, use a dedicated CSV parsing library.