Prevent losing the value of the TextBox of the GridView

 

Below is the code behind:

protected void CheckBox_CheckChanged(object sender, EventArgs e)
{
pnl_InProduct.Visible = true;
GetData();
SetData();
BindSecondaryGrid();
}

private DataTable CreateDataTable()
{
DataTable dt = new DataTable();
dt.Columns.Add("AId");
dt.Columns.Add("AssetsName");
dt.Columns.Add("SubAssetName");
dt.AcceptChanges();
return dt;
}

private DataTable AddRow(GridViewRow gvRow, DataTable dt)
{
DataRow[] dr = dt.Select("AId = '" + gvRow.Cells[1].Text + "'");
if (dr.Length <= 0)
{
dt.Rows.Add();
dt.Rows[dt.Rows.Count - 1]["AId"] = gvRow.Cells[1].Text;
dt.Rows[dt.Rows.Count - 1]["AssetsName"] = gvRow.Cells[2].Text;
dt.Rows[dt.Rows.Count - 1]["SubAssetName"] = gvRow.Cells[3].Text;
dt.AcceptChanges();
}
return dt;
}

private DataTable RemoveRow(GridViewRow gvRow, DataTable dt)
{
DataRow[] dr = dt.Select("AId = '" + gvRow.Cells[1].Text + "'");
if (dr.Length > 0)
{
dt.Rows.Remove(dr[0]);
dt.AcceptChanges();
}
return dt;
}


private void GetData()
{
DataTable dt;
if (ViewState["SelectedRecords"] != null)
dt = (DataTable)ViewState["SelectedRecords"];
else
dt = CreateDataTable();
CheckBox chkAll = (CheckBox)GridView3.HeaderRow.Cells[0].FindControl("chkAll");
for (int i = 0; i < GridView3.Rows.Count; i++)
{
if (chkAll.Checked)
{
dt = AddRow(GridView3.Rows[i], dt);
}
else
{
CheckBox chk = (CheckBox)GridView3.Rows[i].Cells[0].FindControl("chk");
if (chk.Checked)
{
dt = AddRow(GridView3.Rows[i], dt);
}
else
{
dt = RemoveRow(GridView3.Rows[i], dt);
}
}
}
ViewState["SelectedRecords"] = dt;
}

private void SetData()
{
CheckBox chkAll = (CheckBox)GridView3.HeaderRow.Cells[0].FindControl("chkAll");
chkAll.Checked = true;
if (ViewState["SelectedRecords"] != null)
{
DataTable dt = (DataTable)ViewState["SelectedRecords"];
for (int i = 0; i < GridView3.Rows.Count; i++)
{
CheckBox chk = (CheckBox)GridView3.Rows[i].Cells[0].FindControl("chk");
if (chk != null)
{
DataRow[] dr = dt.Select("AId = '" + GridView3.Rows[i].Cells[1].Text + "'");
chk.Checked = dr.Length > 0;
if (!chk.Checked)
{
chkAll.Checked = false;
}
}
}
}
}

private void BindSecondaryGrid()
{
DataTable dt = (DataTable)ViewState["SelectedRecords"];
GridView4.DataSource = dt;
GridView4.DataBind();
}