Delete Button - Invalid postback or callback argument

Question

I am trying to add a "Delete" button to my product-page, but I am constantly having troubles with this error:

Error:

Invalid postback or callback argument. Event validation is enabled using in configuration or <%@ Page EnableEventValidation="true" %> in a page. For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them. If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation.

Stack Trace:

[ArgumentException: Invalid postback or callback argument. Event validation is enabled using in configuration or <%@ Page EnableEventValidation="true" %> in a page. For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them. If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation.]
System.Web.UI.ClientScriptManager.ValidateEvent(String uniqueId, String argument) +8730646
System.Web.UI.Control.ValidateEvent(String uniqueID, String eventArgument) +113
System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +35
System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +10
System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +13
System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +36 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +5563

What I've tried:

Throughout my research I've learned that I can use enableEventValidation="false" and validateRequest="false" but due to security-reasons its not recommended. I tried to set both to False, it fixed the problem (thought I don't have a DELETE Query inserted), but I don't feel comfortable with having some security-settings turned off, just to get rid of an error.

My repeater is located inside the Page_Load, and since I'm using a masterpage, the repeater is also in a form.

Aspx:

<asp:Repeater runat="server" ID="RepProductMenu" OnItemCommand="RepProducts_ItemCommand">
<ItemTemplate>
         [Lots of stuff]......

        <asp:Button ID="BtnDelete" runat="server" Text="Delete" CommandName="Delete" CommandArguement='<%# Eval("ID") %>' /

</ItemTemplate>
</asp:Repeater>

Aspx.cs:

protected void RepProducts_ItemCommand(Object Sender, RepeaterCommandEventArgs e)
{
    if (e.CommandName == "Delete")
    {
        int ID = Int32.Parse(e.CommandArgument.ToString());
        // Add Delete Query
        Response.Write("COMMAND");
    }
}

Any suggestions and idéas are appreciated.

Answer 1

Avoid using Delete as a CommandName, as I believe this is reserved.

Also you have a typo in your Button control. CommandArguement should be CommandArgument

---

If your repeater is being binded at Page_Load and not inside if !(page.IsPostBack) then it will be rebound when the Delete button is clicked. This may cause a problem as the repeater will be rebound before your ItemCommand is ran. Which would make it invalid.

Try changing your code so that if !(page.IsPostBack) is wrapped around the bind.

Answer 2

Okay I found the issue and it is not working. I will provide my new code and hopefully, it can help you aswell :) Please keep in mind, I use a DataAccess in my codebehind so you should just enter your own code there, nonetheless, take a look:

**

Old Code:

**

<asp:Repeater runat="server" ID="RepProductMenu" OnItemCommand="RepProducts_ItemCommand">
<ItemTemplate>
      <asp:Button ID="BtnDelete" runat="server" Text="Slet" CommandName="DeleteProduct" CommandArgument='<%# Eval("ID") %>' />
</ItemTemplate>
</asp:repeater>



 protected void RepProducts_ItemCommand(Object Sender, RepeaterCommandEventArgs e)
    {
        if (e.CommandName == "DeleteProduct")
        {
            int ID = Int32.Parse(e.CommandArgument.ToString());
            // Add Delete Query
            Response.Write("COMMAND");
        }
    }      

First of all, it's not supposed to be a RepeaterCommandEventArgs, but CommandEventArgs

**

New Code:

**

<asp:Repeater runat="server" ID="RepProductMenu" >
<ItemTemplate>
      <asp:Button ID="BtnDelete" runat="server" Text="Slet" CommandName="DeleteProduct" CommandArgument='<%# Eval("ID") %>' />
</ItemTemplate>
</asp:repeater>

protected void OnItemCommand(Object Sender, CommandEventArgs e)
{
    if (e.CommandName == "DeleteProduct")
    {
        DataAccess dataAccess = new DataAccess();

        int ID = Int32.Parse(e.CommandArgument.ToString());
        dataAccess.AddParameter("@id", ID);
        dataAccess.Execute(@"DELETE FROM [Product] WHERE ID = @ID");
        //Response.Write("COMMAND");
    }
}

Answer 3

For me the issue was that the repeater's data-binding in a Page_Load method needed to be put inside 'if (!IsPostBack)' block.

Instead of :

protected void Page_Load(object sender, EventArgs e)
{
    FileLinksRepeater.DataSource = _DataSource;
    FileLinksRepeater.DataBind();
}

try this :

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        FileLinksRepeater.DataSource = _DataSource;
        FileLinksRepeater.DataBind();
    }   
}

This solved the problem for me.