C# Excel到DataGridView而不使用硬代码

我正在尝试将Excel读取到数据网格视图，而不使用硬编码方式。我在尝试这样做时遇到了错误。有人能帮我吗

Excel.Workbook workbook;
        Excel.Worksheet NwSheet;
        Excel.Range ShtRange;
        Microsoft.Office.Interop.Excel.Application ExcelObj = null;
        OpenFileDialog filedlgExcel = new OpenFileDialog();
        filedlgExcel.Title = "Select file";
        filedlgExcel.InitialDirectory = @"c:\";
        filedlgExcel.FileName = txtFileName.Text;
        filedlgExcel.Filter = "Excel Sheet(*.xlsx)|*.xlsx|All Files(*.*)|*.*";
        filedlgExcel.FilterIndex = 1;
        filedlgExcel.RestoreDirectory = true;
        if (filedlgExcel.ShowDialog() == DialogResult.OK)
        {
            //Excel.Workbook theWorkbook = ExcelObj.Workbooks.Open(
            //   filedlgExcel.FileName, 0, true, 5,
            //    "", "", true, Excel.XlPlatform.xlWindows, "\t", false, false,
            //    0, true);
           workbook = ExcelObj.Workbooks.Open(filedlgExcel.FileName , Missing.Value, Missing.Value,
                Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value,
                Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value);
            NwSheet = (Excel.Worksheet)workbook.Sheets.get_Item(1);
        ShtRange = NwSheet.UsedRange; //gives the used cells in sheet
        //Reading Excel file.
        //Creating dataTable to read the containt of the Sheet in File.

        //Set header name
        for (int Cnum = 1; Cnum <= ShtRange.Columns.Count; Cnum++)
        {
            dt.Columns.Add(new DataColumn((ShtRange.Cells[1, Cnum] as Excel.Range).Value2.ToString()));
        }
        dt.AcceptChanges();
        //store coumn names to array
        string[] columnNames = (from dc in dt.Columns.Cast<DataColumn>() select dc.ColumnName).ToArray();

        //populate fields
        for (int Rnum = 2; Rnum <= ShtRange.Rows.Count; Rnum++)
        {
            DataRow dr = dt.NewRow();
            for (int Cnum = 1; Cnum <= ShtRange.Columns.Count; Cnum++)
            {
                dr[Cnum - 1] = (ShtRange.Cells[Rnum, Cnum] as Excel.Range).Value2.ToString();
            }
            dt.Rows.Add(dr);
            dt.AcceptChanges();
        }
        workbook.Close(true, Missing.Value, Missing.Value);
        ExcelObj.Quit();

        foreach (DataRow dr in dt.Rows)
        {
            string strEmployee = dr["Employee Name"].ToString();
            obj1 = new List<employeeschedule>();
            for (int i = 1; i < dt.Columns.Count; i++)
            {
                string period = dr[i].ToString();
                string[] split = period.Split('–');
                employeeschedule es = new employeeschedule();
                string day = columnNames[i];
                if (split[0] == "Rest Day")
                {
                    es.day = day;
                    es.startTime = split[0];
                    es.endTime = split[0];
                    es.restDay = "Yes";
                }
                else
                {
                    es.day = day;
                    es.startTime = split[0];
                    es.endTime = split[1];
                    es.restDay = "No";
                }
                obj1.Add(es);
            }

            dict.Add(strEmployee, obj1);
            dgvEmployeeShift.DataSource = dt;
        }
            }
        }

---

任何帮助都将不胜感激。

您在开始时将ExcelObj设置为null，然后再也不初始化它

Microsoft.Office.Interop.Excel.Application ExcelObj = null;

---

尝试使其

=新建Microsoft.Office.Interop.Excel.Application（）
或者，您可以使用
OleDb
提供程序读取Excel工作表

OleDb是ADO.NET（.NET framework的数据库集成API）的提供程序API，它公开来自不同数据源的数据，包括Microsoft Access数据库或Microsoft Excel电子表格等

查看MSDN文章/教程的链接：



此外，您不需要所有缺少的.Value字段，它们是可选的，您可以将它们省略。正在声明ExcelObj，不能为=new ExcelObj（）；还有其他的方法吗？是的，对不起，请看我上面的编辑。应为=新建Excel.Application（）；如果您这样做：使用Excel=Microsoft.Office.Interop.Excel；然后你可以在你的代码中使用Excel.Application等，而不是microsoft.office.interop.Excel…我不太熟悉OleDb，因此我使用工作簿，因为我建议使用。如何在查询字符串中包含特定范围？
Microsoft.Office.Interop.Excel.Application ExcelObj = null;

string cnStr=@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=c:\myFolder\myExcel2007file.xlsx;Extended Properties=" + "\"Excel 12.0 Xml;HDR=YES;IMEX=1\"";
DataTable dt=new DataTable();
string sql="Select * From [Sheet1$]";
using(OleDbConnection cn=new OleDbConnection(cnstr))
{
  using(OleDbDataAdapter adapter=new OleDbDataAdapter(sql,cn))
   {
     adapter.Fill(dt);
   }
}