Bonsoir à tous. Peut etre avez vous la solution à mon pbe. J'ai un gridview  avec differentes colonnes dont une contient un bouton edit. Celui ci déclenche l'apparition d'un popup. Tout fonctionne bien la 1ere fois, mais lorsque je clique une nouvelle fois sur le bouton edit, plus rien ne se passe.

Voici mon code aspx

<div class="row">
                   <div class="col-md-12">
                                <asp:GridView ID="GridView1" runat="server" CssClass="footable" AutoGenerateColumns="false" Style="max-width:500px">
                                    <Columns>
                                        <asp:TemplateField HeaderText="Image">
                                            <ItemTemplate>
                                                <asp:Image ID="Image3" runat="server" Height = "100" Width = "100" ImageUrl = '<%# Eval("id_perso", "ImageCSharp2.aspx?ImageID={0}")%>' />
                                            </ItemTemplate>
                                        </asp:TemplateField>
                                        <asp:BoundField DataField="id_perso" HeaderText="ID" ItemStyle-HorizontalAlign="center" Visible="false" />
                                        <asp:BoundField DataField="statut" HeaderText="Statut" ItemStyle-HorizontalAlign="center" />
                                        <asp:BoundField DataField="nom_perso" HeaderText="Nom" ItemStyle-HorizontalAlign="center" />
                                        <asp:BoundField DataField="prenom_perso" HeaderText="Prénom" ItemStyle-HorizontalAlign="center" />
                                        <asp:BoundField DataField="adresse_perso" HeaderText="Adresse" ItemStyle-HorizontalAlign="center" />
                                        <asp:BoundField DataField="code_postal_perso" HeaderText="Code Postal" ItemStyle-HorizontalAlign="center" />
                                        <asp:BoundField DataField="ville_perso" HeaderText="Ville" ItemStyle-HorizontalAlign="center" />
                                        <asp:BoundField DataField="tel_perso" HeaderText="Téléphone" ItemStyle-HorizontalAlign="center" />
                                        <asp:BoundField DataField="mail_perso" HeaderText="Email" ItemStyle-HorizontalAlign="center" />
                                        <asp:TemplateField HeaderText="">
                                            <ItemTemplate>
                                                <asp:Button id="btnEdit" runat="server" Text="Editer" OnClick="Edit" CommandArgument='<%# Eval("id_perso") %>' class="btn btn-primary" />
                                            </ItemTemplate>
                                        </asp:TemplateField>
                                        <asp:TemplateField HeaderText="">
                                            <ItemTemplate>
                                                <asp:Button ID="btnSupprimer" runat="server" Text="Supprimer" OnClick="Delete" CommandArgument='<%# Eval("id_perso") %>' CssClass="btn btn-danger" />
                                            </ItemTemplate>
                                        </asp:TemplateField>


                                    </Columns> 

                                </asp:GridView>
                            </div>
                        </div>
<asp:LinkButton ID="lnkFake" runat="server"></asp:LinkButton>

        <asp:Panel ID="pnlAddUpdatePersonnelDetails" runat="server" CssClass="modalPopup" Style="Display:none;">
            <div style="overflow-y:auto;overflow-x:hidden;max-height:450px;width:600px;">
                <div class="modal-header">
                    <asp:Label ID="lblHeading" runat="server" CssClass="modal-title"></asp:Label>
                </div>
                <div class="modal-body">
                    <div class="col-md-3">
                        <asp:Image ID="Image2" runat="server" ImageAlign="Middle" Width="100px" Height="100px" Style="border:1px solid black;"/>
                        <asp:TextBox ID="txtStatut" runat="server" Text="Label"></asp:TextBox>
                    </div>
                    
                    <div class="col-md-9">
                        <div class="form-group col-md-12">
                            <div class="col-md-6">
                                <label for="txtGenre" runat="server">Genre :</label>
                            </div>
                            <div class="col-md-6">
                                <asp:TextBox ID="txtGenre" runat="server" CssClass="form-control" ReadOnly="true"></asp:TextBox>
                            </div>
                        </div>
                        
                        <div class="form-group col-md-12">
                            <div class="form-group">
                                <div class="row">
                                    <div class="col-md-3">
                                        <label for="txtNom">
                                            Nom
                                        </label>
                                    </div>
                                    <div class="col-md-6">
                                        <asp:TextBox ID="txtNom" runat="server" CssClass="form-control" placeholder="Nom" Width="150px"></asp:TextBox>
                                    </div>
                                </div>
                            </div>
                        </div>

                        <div class="form-group col-md-12">
                            <div class="col-md-6">
                                <label for="txtPrenom">
                                    Prénom : 
                                </label>
                            </div>
                            <div class="col-md-6">
                                <asp:TextBox ID="txtPrenom" runat="server" CssClass="form-control" Width="150px" ReadOnly ="false"></asp:TextBox>
                            </div>
                        </div>
                        <div class="form-group col-md-12">
                            <div class="col-md-6">
                                <label for="FileUpload2">Modifier la photo :</label>
                            </div>
                            <div class="col-md-6">
                                <asp:FileUpload ID="FileUpload2" runat="server" CssClass="btn btn-warning"/>
                            </div>
                        </div>
                    </div>
                </div>

                <div align="center" class="modal-footer">
                    <div class="row">
                        <div class="col-md-12">
                            <asp:HiddenField ID="hfAddEditPersonnelId" runat="server" Value="0" />
                            <asp:HiddenField ID="hfAddEdit" runat="server" Value="ADD" />
                            <asp:Button ID="btnSave" runat="server" Text="Sauvegarder" OnClick="Save" CssClass="btn btn-success" ValidationGroup="Personnel" />
                            <button id="btnCancel" runat="server" class="btn btn-primary">Annuler</button>
                        </div>
                    </div>
                </div>
            </div>
        </asp:Panel>

        <uc:ModalPopupExtender ID="mpeAddUpdatePersonnel" runat="server" PopupControlID="pnlAddUpdatePersonnelDetails" TargetControlID="lnkFake" BehaviorID="mpeAddUpdatePersonnel" CancelControlID="btnCancel" BackgroundCssClass="modalBackground" ></uc:ModalPopupExtender>

Code behind :

protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                BindPerso();
            }
        }

private void BindPerso()
        {
            DataTable dt = new DataTable();
            using (RestauDBEntities1 db = new RestauDBEntities1())
            {
                if (db.PERSONNEL.Count() > 0)
                {
                    GridView1.DataSource = (from pers in db.PERSONNEL select new { pers.id_perso, pers.statut, pers.nom_perso, pers.prenom_perso, pers.adresse_perso, pers.code_postal_perso, pers.ville_perso, pers.date_entree_perso, pers.salaire_brut, pers.tel_perso, pers.mail_perso, pers.secu_perso, pers.date_naissance, pers.lieu_naissance, pers.genre, pers.pseudo, pers.mdp, pers.picture, pers.observation }).ToList();

                    GridView1.DataBind();
                }
                else
                {
                    GridView1.DataSource = null;
                    GridView1.DataBind();
                }
            }
            
        }

public void Edit(object sender, EventArgs e)
        {
            //Label2.Visible = false;
            lblHeading.Text = "Update Employee Details";
            hfAddEditPersonnelId.Value = (sender as Button).CommandArgument;

            try
            {
                using (RestauDBEntities1 db = new RestauDBEntities1())
                {
                    if(db.PERSONNEL.Count() > 0)
                    {
                        int persoID = Convert.ToInt16(hfAddEditPersonnelId.Value);
                        PERSONNEL persoObject = (from p in db.PERSONNEL
                                                 where p.id_perso == persoID
                                                 select p).FirstOrDefault();
                        txtNom.Text = Convert.ToString(persoObject.nom_perso);
                        txtPrenom.Text = Convert.ToString(persoObject.prenom_perso);
                        

                        byte[] barrImg = (byte[])persoObject.picture;

                        if (barrImg != null && barrImg.Length > 0)
                        {

                            string base64String = Convert.ToBase64String(barrImg, 0, barrImg.Length);
                            Image2.ImageUrl = "data:image/jpg;base64," + base64String;
                        }

                            mpeAddUpdatePersonnel.Show();
                    }
                }
            }
catch (Exception ex)
            {
                Label2.Text = ex.Message.ToString();
                Label2.Visible = true;
            }
        }

Merci pour votre aide