如何在回发中从gridview获取动态文本框的值？

Question

我正在编辑文本框并更改其值。下面是代码片段。

protected void btnedit_Click(object sender, EventArgs e)
{

    TextBox txtmonday = new TextBox();
    txtmonday.ID = "txtmonday1";
    int index = GridView1.EditIndex;

    Button btn = (Button)sender;


    GridViewRow gvr = (GridViewRow)btn.NamingContainer;

    int getindex = gvr.RowIndex;

    //string headertext = this.GridView1.Columns[1].HeaderText;
    string id = GridView1.Rows[getindex].Cells[4].Text;

    DataTable dtfrweekend = new DataTable();
    connfordata.Open();
    SqlCommand cmdfrgetweekend = new SqlCommand("select s001_Weekending as Weekend from dbo.s001_Timesheets where s001_TimesheetsID ='" +id+ "' ", connfordata);
    SqlDataAdapter dafrweekend = new SqlDataAdapter(cmdfrgetweekend);
    dafrweekend.Fill(dtfrweekend);
    connfordata.Close();

        string get = GridView1.HeaderRow.Cells[3].Text.ToString();

        BoundField bf = new BoundField();
        bf.DataField = "Monday";
        txtmonday.Text = GridView1.Rows[getindex].Cells[3].Text;
        GridView1.Rows[getindex].Cells[3].Controls.Add(txtmonday);
}

当我点击更新时，我无法在编辑模式下更改值。请建议一个解决方案以获取之前更改的值。谢谢.Below是用于更新的代码段。

protected void btnupdate_Click(object sender, EventArgs e)
{

    //string get = txtmonday.Text;
    //String sValue = Request.Form["txtmonday"];
   // GridView1.DataBind();


    TextBox tbfrreplace = new TextBox();

    Button btn = (Button)sender;
    GridViewRow gvr = (GridViewRow)btn.NamingContainer;
    int getindex = gvr.RowIndex;

    BoundField bf2 = new BoundField();
    bf2.DataField = "Monday";

    //tbfrreplace.Text = GridView1.Rows[getindex].Cells[3].Text;
   // TextBox tbfrreplace1 = GridView1.FindControl("tbfrreplace") as TextBox;
   // GridView1.Rows[getindex].Cells[3].Controls.Add(tbfrreplace);
}