尝试以下代码

Try the following code

protected void Button2_Click(object sender, EventArgs e)
   {
       if(Session["dt1"] != null)
       {
          dt1 = (DataTable)Session["dt1"];
       }

       DataRow dr1 = dt1.NewRow();
       dr1[0] = TextBox2.Text;
       dr1[1] = TextBox4.Text;
       dr1[2] =TextBox3.Text;
       dr1[3] =TextBox5.Text;
       dt1.Rows.Add(dr1);
       GridView1.DataSource = dt1;
       GridView1.DataBind();

       Session["dt1"] = dt1;

   }

您好，请尝试以下代码

hi try the following code

Button_Click()
{
    DataTable dt = new DataTable();
    DataRow dr;
    dt.Columns.Add("Name");
    dt.Columns.Add("Address");
    dt.Columns.Add("Number");
    //First fill all the date present in the grid
    for (int intCnt = 0; intCnt < grd.Rows.Count; intCnt ++)
    {
        if (grd.Rows[intCnt].RowType == DataControlRowType.DataRow)
        {
        dr = dt.NewRow();
        dr["Name"] = grd.Rows[intCnt].Cells[0].Value;
        dr["Address"] = grd.Rows[intCnt].Cells[1].Value;
        dr["Number"] = grd.Rows[intCnt].Cells[2].Value;
        dt.Rows.Add(dr);
        }
    }
    dr = dt.NewRow();
    dr["Name"] = txt1.Text;
    dr["Address"] = txt2.Text;
    dr["Number"] = txt3.Text;
    dt.Rows.Add(dr);
    grd.DataSource = dt;
    grd.DataBind();
}

如果我犯了任何语法错误，请更正，因为我直接在记事本中写了这段代码

Please make corrections if I made any syntactic mistake because I wrote this code directly in the notepad