i have a gridview that creates a new row with a new gridview in it the method of creating the second gridview is :

protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
{
    if (e.CommandName == "PopExtendedGrid")
    {


    GridView _gridView = (GridView)sender;
int _rowIndex2 = int.Parse(e.CommandArgument.ToString());
GridView _ChildGrid = new GridView();
Control x = _gridView.Rows[_rowIndex2 + 1].Cells[1].Controls[1];
int Oid = int.Parse(((Label)x).Text);
_ChildGrid.DataSource = hs.GetExtendedGrid(Oid);
_ChildGrid.ID = "ChildGrid";
_ChildGrid.AutoGenerateColumns = false;
_ChildGrid.CssClass = "ChildGridS";
_ChildGrid.HeaderStyle.CssClass = "CreateHead";
BoundField one = new BoundField();
one.DataField = "ItemID";
one.HeaderText = "קוד מוצר";
_ChildGrid.Columns.Add(one);

BoundField two = new BoundField();
two.DataField = "ItemName";
two.HeaderText = "שם מוצר";
_ChildGrid.Columns.Add(two);

BoundField three = new BoundField();
three.DataField = "ItemSize";
three.HeaderText = "גודל מוצר";
_ChildGrid.Columns.Add(three);

GridViewRow tr = new GridViewRow(_rowIndex2 + 2 +10*this.GridView1.PageIndex,-1 , DataControlRowType.EmptyDataRow , DataControlRowState.Normal);
TableCell tc = new TableCell();
tc.ColumnSpan = _gridView.Columns.Count;
tc.Controls.Add(_ChildGrid);
tr.Cells.Add(tc);
if ((DataView)Session["dataSource"] != null)
 {
 DataView dv = (DataView)Session["dataSource"];
 this.GridView1.DataSource = dv;
 this.GridView1.DataBind();
 }
                else
                {
                    if (Session["lvl"].ToString() == "high")
                    {
                        PopulateGridViewAdmin();
                    }
                    else
                    {
                        PopulateGridViewUser();
                    }
                }
this.GridView1.Controls[0].Controls.AddAt(_rowIndex2 + 2, tr);
Session["ChildIndex"] = (_rowIndex2 + 2).ToString();
_ChildGrid.DataBind();
  }
}

并且认为,在任何时候都需要执行另一条指挥或与格罗西格格格格格格格格格格格格格格格格格格格格格格格格格格格格格格格格格格格格言相关的指挥,这样一来,就将翻一番:

this.GridView1.Controls[0].Controls.RemoveAt(int.Parse(Session["ChildIndex"].ToString()));

而后又重新接纳主电网,但在有机会这样做之前,这一错误继续流行:

Failed to load viewstate.  The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate during the previous request.  For example, when adding controls dynamically, the controls added during a post-back must match the type and position of the controls added during the initial request.

im very frustrated by this and i will take any answer with great gratitude thanks in advance