用户控件内部的可排序DataGrid

Question

I need to implement sortable DataGrid inside User Control.

My main page code behind looks like this:

protected override void OnInit(EventArgs e)
{
    base.OnInit(e);

    myPlaceHolder.Controls.Add(page.LoadControl("~/myControl.ascx") as MyCtrl);
}

User Control looks like this:

<asp:DataGrid ID="myGrid" runat="server" Width="100%" AutoGenerateColumns="False"
    AllowSorting="True" OnSortCommand="Grid_Sort" EnableViewState="true" >
        <Columns>
            <asp:BoundColumn DataField="Clmn1" SortExpression="" HeaderText="" />
            <asp:BoundColumn DataField="Clmn2" SortExpression="Clmn2" HeaderText="Clmn2header" />
        </Columns>
    </asp:DataGrid>

So I faced following problem: when I click on automatic generated link button Clmn2header to sort data, it cause the main page to reload (not post back) and hence to create new user control. So post back never occure and sorting method Grid_Sort is never fired.

I sure that ViewState is enabled.

Help me, please. What have I done wrong? Thank you.

EDIT

I just simplify, actually, user control initializing looks like this:

protected override void OnInit(EventArgs e)
{
    base.OnInit(e);

    myPlaceHolder.Controls.Add(MyCtrl.createInstance(/*some params*/));
}

And crete instance method:

public static MyCtrl createInstance(/*some params*/)
{
    MyCtrl ctrl = page.LoadControl("~/myControl.ascx") as MyCtrl;
    ctrl._init(/*some params*/);
    return ctrl;
}

private void _init(/*some params*/)
{
    /*setting controls properties with params*/
}

Answer 1

What is MyCtrl ? why casting as you are using loadcontrol method ? below line should be suffice to instantiate your control,

myPlaceHolder.Controls.Add(page.LoadControl("~/myControl.ascx"));

Did you put IsPostBack() checkpoint in your page_load event of the page & control, i am quite sure that when you click on column headertext link, there should not be full page postback.

if (!IsPostBack) { }

let me know if your sort command event is not hit still.