.net上传文件，利用npoi读取文件信息到datatable里

整理代码，.net上传文件，利用npoi读取文件到datatable里，使用了FileUpload控件，代码如下：

protected void Button1_Click(object sender, EventArgs e)
{
    try
    {
        #region 上传文件
        if (FileUpload1.HasFile)//判断是否存在上传文件
        FileUpload1.SaveAs(Server.MapPath("~/") + FileUpload1.FileName);
        else
        {
            ScriptManager.RegisterClientScriptBlock(this, GetType(), "aaa", "alert('上传文件不存在或上传文件为空，请检查文件');", true);
            return;
        }
        #endregion
        #region 读取文件
        DataTable dt = null;
        string fileEx = FileUpload1.FileName.Substring(FileUpload1.FileName.LastIndexOf(".") + 1);
        if (fileEx == "xls")
        {
            dt = IO.ImportExcelFile(Server.MapPath("~/") + FileUpload1.FileName);
        }
        else if (fileEx == "xlsx")
        {
            dt = IO.ImportExcelFilexlsx(Server.MapPath("~/") + FileUpload1.FileName);
        }
        if (dt.Rows.Count < 1)
        {
            ScriptManager.RegisterClientScriptBlock(this, GetType(), "aaa", "alert('上传文件为空，请检查文件内容');", true);
            return;
        }
        #endregion
    }
    catch (Exception ex)
    {
        ScriptManager.RegisterClientScriptBlock(this, GetType(), "aaa", "alert('系统异常，" + ex + "');", true);
    }
}

npoi读取文件的方法：

public static DataTable ImportExcelFile(string filePath)
{
    HSSFWorkbook hssfworkbook;
    #region//初始化信息
    try
    {
        using (FileStream file = new FileStream(filePath, FileMode.Open, FileAccess.Read))
        {
            hssfworkbook = new HSSFWorkbook(file);
        }
    }
    catch (Exception e)
    {
        throw e;
    }
    #endregion
    NPOI.SS.UserModel.ISheet sheet = hssfworkbook.GetSheetAt(0);
    System.Collections.IEnumerator rows = sheet.GetRowEnumerator();
    DataTable dt = new DataTable();
    for (int j = 0; j < (sheet.GetRow(0).LastCellNum); j++)
    {
        dt.Columns.Add(sheet.GetRow(0).GetCell(j).ToString());
    }
    while (rows.MoveNext())
    {
        HSSFRow row = (HSSFRow)rows.Current;
        if (row.RowNum != 0)
        {
            DataRow dr = dt.NewRow();
            for (int i = 0; i < row.LastCellNum; i++)
            {
                NPOI.SS.UserModel.ICell cell = row.GetCell(i);
                if (cell == null)
                {
                    dr[i] = null;
                }
                else
                {
                    dr[i] = cell.ToString();
                }
            }
            dt.Rows.Add(dr);
        }
    }
    return dt;
}
public static DataTable ImportExcelFilexlsx(string filePath)
{
    XSSFWorkbook hssfworkbook;
    #region//初始化信息
    try
    {
        using (FileStream file = new FileStream(filePath, FileMode.Open, FileAccess.Read))
        {
            hssfworkbook = new XSSFWorkbook(file);
        }
    }
    catch (Exception e)
    {
        throw e;
    }
    #endregion
    NPOI.SS.UserModel.ISheet sheet = hssfworkbook.GetSheetAt(0);
    System.Collections.IEnumerator rows = sheet.GetRowEnumerator();
    DataTable dt = new DataTable();
    for (int j = 0; j < (sheet.GetRow(0).LastCellNum); j++)
    {
        dt.Columns.Add(sheet.GetRow(0).GetCell(j).ToString());
    }
    while (rows.MoveNext())
    {
        XSSFRow row = (XSSFRow)rows.Current;
        if (row.RowNum != 0)
        {
            DataRow dr = dt.NewRow();
            for (int i = 0; i < row.LastCellNum; i++)
            {
                NPOI.SS.UserModel.ICell cell = row.GetCell(i);
                if (cell == null)
                {
                    dr[i] = null;
                }
                else
                {
                    dr[i] = cell.ToString();
                }
            }
            dt.Rows.Add(dr);
        }
    }
    return dt;
}