Ispostback Asp.net

Question

My Asp.net application (aspx) has two Label-type Controls that need to be filled with information from a Request Querystring. In Page_load I do the treatment so that the Controls of type Label receive this information and actually receive, but do not render, that is, it is not displayed on the page. I did a test by placing constants in place of the values of Request Querystring and when I do this the Label type Controls appear filled. What could this be? I read a lot about Viewstate and his commands but none solved.

insira o código aqui
<asp:Panel ID="panFeedBack" runat="server">
    <div class="row">
        <div class="col-xs-8">
            <div class="control-group">
                <div class="controls">
                    <asp:Label ID="lblMarcacao" runat="server"></asp:Label>
                </div>
            </div>
        </div>
    </div>
</asp:Panel>


insira o código aqui
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
    If Not Request.QueryString.Item("id") Is Nothing Then
        Dim QueryStrMarcacao As String = Request.QueryString.Item("id").Split("|")(1)
        lblMarcacao.Text = "Marcação: " & QueryStrMarcacao
    End If
End Sub

Answer 1

Try the code:

If Not Request.QueryString("id") Is Nothing Then
     Dim QueryStrMarcacao As String = Request.QueryString("id")
     lblMarcacao.Text = "Marcação: " & QueryStrMarcacao
End If

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As for the Viewstate, it is the form of the . net "identify" the status of the page, for example the "Ispostback" used in Page_load, it identifies if it is the first time you are accessing the page, so it is not a postBack (Reload of the page), but if used any item on the page that generates postBack, example a droDownList that loads another, the page will generate a postBack and through this identification you will be able to keep the status of the items on the page