Gridview edit button is firing only once

Question

Hi everyone. Maybe someone have the solution for my probleme. I have a gridview with different columns. One of them is for thye edit button which display a popup details view. Everything works fine the first time I click on the edit button. But if I click again on the same or another edit button, nothing happens. The debugger says nothing. All the variable seems to pass without issues. I don't know what to do to solve my issue. Is someone has a idea ? Thank in advance

My aspx code :

<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>

My 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;
}
}