C# NPOI读取.xls

您可以使用C#的NPOI库来读取.xls文件。首先，您需要使用`ReadFromExcelFile`方法来读取文件并将数据存储在一个DataTable中。该方法使用`IWorkbook`接口来打开文件，并根据文件的扩展名选择适当的工作簿类型。然后，它遍历每一行和每一列，将单元格的值存储在DataTable中。最后，您可以使用`DataTableToExcel`方法将DataTable中的数据写入到.xls文件中。

以下是一个示例代码，演示了如何使用NPOI库读取.xls文件：

public void ReadFromExcelFile(string filePath)
{
    IWorkbook wk = null;
    string extension = System.IO.Path.GetExtension(filePath);
    try
    {
        FileStream fs = File.OpenRead(filePath);
        if (extension.Equals(".xls"))
        {
            wk = new HSSFWorkbook(fs);
        }
        else
        {
            wk = new XSSFWorkbook(fs);
        }
        fs.Close();

        ISheet sheet = wk.GetSheetAt(0);
        IRow row = sheet.GetRow(0);
        int offset = 0;
        for (int i = 0; i <= sheet.LastRowNum; i++)
        {
            row = sheet.GetRow(i);
            if (row != null)
            {
                for (int j = 0; j < row.LastCellNum; j++)
                {
                    string value = row.GetCell(j).ToString();
                    Console.Write(value.ToString() + " ");
                }
                Console.WriteLine("\n");
            }
        }
    }
    catch (Exception e)
    {
        Console.WriteLine(e.Message);
    }
}

您还可以使用`OpenFileDialog`来选择要读取的.xls文件。以下是一个示例代码，演示了如何使用`OpenFileDialog`选择.xls文件：

private void Button_SelcetFile_Click(object sender, EventArgs e)
{
    OpenFileDialog OFD = new OpenFileDialog();
    OFD.Filter = "xls files (*.xls)|*.xls|All files (*.*)|*.*";
    OFD.RestoreDirectory = true;
    if (OFD.ShowDialog() == DialogResult.OK)
    {
        string filePath = OFD.FileName;
        ReadFromExcelFile(filePath);
    }
}

希望这可以帮助到您！
#### 引用[.reference_title]
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