Button onClick does not fire in GridView inside of TemplateField

Question

I'm trying to write a code that would update only one record for the data.

I do not need to be able to update every field on the row, only one particular field.

I have page that defines a GridView as following:

<asp:Content runat="server" ID="BodyContent" ContentPlaceHolderID="MainContent">
<UpdatePanel> 
    <ContentTemplate>   
 <fieldset style="width: 1%">
        <legend>Search Customer</legend>
        <table>
            <tr>
                <td>
                <asp:DropDownList id="ddlSearchOption"
                    AutoPostBack="True"
                    OnSelectedIndexChanged="ddlSearchOption_SelectedIndexChanged"
                    runat="server">
                    <asp:ListItem Selected="True" Value="SearchBy"> Search By </asp:ListItem>
                    <asp:ListItem Value="CustID"> Customer ID </asp:ListItem>
                    <asp:ListItem Value="CustFirst"> First Name </asp:ListItem>
                    <asp:ListItem Value="CustLast"> Last Name </asp:ListItem>
                    <asp:ListItem Value="CustCity"> City </asp:ListItem>
                </asp:DropDownList>
                </td>
      <asp:Panel id="pnlCustSearch" runat="server" >
                    <td>
             <asp:Label id="lblEntry" runat="server" Text="" width="120px"></asp:Label>
                    </td>
                    <td>
                        <asp:TextBox id="txtSearchOptions" runat="server" width="50px">Hello</asp:TextBox>
                    </td>
                    <td>
                        <asp:Button id="btnFind" Text="Search" runat="server" onClick="btnFind_Click"></asp:Button>
                    </td>
    </asp:Panel>
            </tr>
        </table>
    </fieldset>
    <div id ="msg">
    <asp:Label id="lblMsg" runat="server" Text=""></asp:Label>
    </div>
    <div id="gridShow">

  <asp:GridView ID="GridView1" runat="server" GridLines="None" AutoGenerateColumns="false"
  AlternatingRowStyle-BackColor="#EEEEEE" EditRowStyle-BorderColor="Red">           
  <Columns>           
     <asp:TemplateField Visible="true" HeaderText="Customer ID">
        <ItemTemplate>
          <asp:Label runat="server" ID="lblCustID" Text='<%#Eval("CustID")%>' />
        </ItemTemplate>
     </asp:TemplateField>

     <asp:TemplateField HeaderText="First Name">

        <ItemTemplate>
         <asp:Label runat="server" ID="lblFirstName" Text='<%#Eval("CustFirstName") %>' />
        </ItemTemplate>
     </asp:TemplateField>
     <asp:TemplateField HeaderText="Last Name">
        <ItemTemplate>
          <asp:Label runat="server" ID="lblLastName" Text='<%#Eval("CustLastName") %>' />
        </ItemTemplate>
     </asp:TemplateField>

     <asp:TemplateField HeaderText="City">
       <ItemTemplate>
         <asp:Label runat="server" ID="lblCity" Text='<%#Eval("CustCity") %>' />
       </ItemTemplate>
     </asp:TemplateField>
     <asp:TemplateField HeaderText="Email">  
      <ItemTemplate>
         <asp:TextBox runat="server" ID="txtEmail" Text='<%#Eval("CustEmail") %>' />
          <asp:Button runat="server" ID="btnUpdate" Text="Update" onClick="GridView1_btnUpdate_Click"/>
  <asp:RequiredFieldValidator runat="server" ID="rfdCountry" ControlToValidate="txtEmail" 
             ValidationGroup="var1" ErrorMessage="*" />
       </ItemTemplate>
     </asp:TemplateField>

 </Columns>
 </asp:GridView>

</div>
</ContentTemplate>
</UpdatePanel> 

 </asp:Content>

Then in codebehind I write the following:

    protected void GridView1_btnUpdate_Click(Object sender, EventArgs e)
    {
       //Code goes here
    }

When clicking button to update email nothing happens.

What am I doing wrong?

I tried to use one of suggestions here:

        if (!IsPostBack)
        {
            GridView1.DataSource = App_Data.DataHandler.GetData("fname", "de");
            GridView1.DataBind();
            GridView1.Visible = true;
        }

The data is displayed but the click event does not work anyway

I added the following to my GridView definition:

onrowcommand="GridView1_RowCommand"

and added the code suggested:

             <asp:Button runat="server" ID="btnUpdate" Text="Update" CommandName="UpdateEmail" 
             CommandArgument="<%# ((GridViewRow) Container).RowIndex %>"/>

In my .cs file I added the following:

        protected void GridView1_RowCommand(Object sender, GridViewCommandEventArgs e)
    {
        if (e.CommandName == "UpdateEmail")
        {
            //Get the index from the argument
            int index = Convert.ToInt32(e.CommandArgument);
            //Get the row
            GridViewRow row = GridView1.Rows[index];

            //Do whatever you need with your row here!
        }
    }

Still, click event does not fire.

Ok, here is my code behind .cs file:

public partial class index : System.Web.UI.Page
{
    protected override object LoadPageStateFromPersistenceMedium()
    {
        return Session["__VIEWSTATE"];
    }
    protected override void SavePageStateToPersistenceMedium(object viewState)
    {
        Session["VIEWSTATE"] = viewState;
    }

    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
            Reset();
        else
            lblMsg.Text = "";

    }

    protected void Reset()
    {
        pnlCustSearch.Visible = false;
        GridView1.Visible = false;
        lblMsg.Text = "";
    }

    protected void ddlSearchOption_SelectedIndexChanged(object sender, EventArgs e)
    {

            Reset();
            String ddlSelected = ddlSearchOption.SelectedValue;
            if (ddlSelected != "")
            {
                ViewState["ddlSelected"] = ddlSelected;
                pnlCustSearch.Visible = true;
                SelectLabel(ddlSelected);
            }
    }

    protected void SelectLabel(String choice)
    {
        switch (choice)
        {
            case "CustID":
                lblEntry.Text = "Enter Customer ID";
                break;
            case "CustFirst":
                lblEntry.Text = "Enter First Name";
                break;
            case "CustLast":
                lblEntry.Text = "Enter Last Name";
                break;
            case "CustCity":
                lblEntry.Text = "Enter City";
                break;
            default: 
                lblEntry.Text = "Enter Customer ID";
                break;
        }
    }

    protected void btnFind_Click(object sender, EventArgs e)
    {
        GridView1.Visible = true;
        String option = (String)ViewState["ddlSelected"];
        String input = txtSearchOptions.Text.Trim();

        GridView1.DataSource = DataHandler.GetData(option,input);
        GridView1.DataBind();
        GridView1.Visible = true;

    }

    protected void GridView1_RowCommand(Object sender, GridViewCommandEventArgs e)
    {
        if (e.CommandName == "UpdateEmail")
        {
            //Get the index from the argument
            int index = Convert.ToInt32(e.CommandArgument);
            //Get the row
            GridViewRow row = GridView1.Rows[index];

            //Do whatever you need with your row here!
        }
    }

    protected void btnUpdate_Click(Object sender, EventArgs e)
    {
        String txt = null;
        txt = "here";
    }
}

Answer 1

When you try to handle events from GridView, you need to use a CommandName and a CommandArgument then handle the RowCommand event from the GridView.

See http://msdn.microsoft.com/... for reference.

ASP.Net page should look like :

<asp:ButtonField runat="server" ID="btnUpdate" Text="Update" 
     CommandName="UpdateEmail" 
     CommandArgument="<%# CType(Container,GridViewRow).RowIndex %>" />

In the RowCommand event :

if (e.CommandName == "UpdateEmail")
{
    //Get the index from the argument
    int index = Convert.ToInt32(e.CommandArgument);
    //Get the row
    GridViewRow row = GridView1.Rows[index];

    //Do whatever you need with your row here!
}

Answer 2

Actually, the answer was much easier then I thought originally. I just used different values to set session: __VIEWSTATE and VIEWSTATE

    protected override object LoadPageStateFromPersistenceMedium()
    {
        return Session["__VIEWSTATE"];
    }
    protected override void SavePageStateToPersistenceMedium(object viewState)
    {
    Session["VIEWSTATE"] = viewState;
    }

As soon as I changed it, button was able to fire events.

Thank you

Answer 3

I got it, finally. I had to change <asp:Button/> to

    `<asp:ButtonField Text="Update Email" CommandName="UpdateEmail"`

and remove it from ItemTemplate.

But why this was a problem. What I wanted to do is just to display textfield in the same itemtemplate with button?