how to import excel file in csharp

main.cs
using Microsoft.Office.Interop.Excel;

// ...

Application excel = new Application();
Workbook workbook = excel.Workbooks.Open(@"C:\path\to\file.xlsx");

Worksheet worksheet = workbook.ActiveSheet;

int rowCount = worksheet.UsedRange.Rows.Count;
int colCount = worksheet.UsedRange.Columns.Count;

for (int i = 1; i <= rowCount; i++)
{
    for (int j = 1; j <= colCount; j++)
    {
        Range range = worksheet.Cells[i, j];
        Console.Write(range.Value2 + "\t");
    }
    Console.WriteLine();
}

workbook.Close();
excel.Quit();
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