Confirm postback OnClientClick button ASP.NET

Question

<asp:Button runat="server" ID="btnUserDelete" Text="Delete" CssClass="GreenLightButton"
                           OnClick="BtnUserDelete_Click"
                           OnClientClick="return UserDeleteConfirmation();" 
 meta:resourcekey="BtnUserDeleteResource1" />

I have tried:

function UserDeleteConfirmation() {
        if (confirm("Are you sure you want to delete this user?"))
            return true;
        else
            return false;
}

and

function UserDeleteConfirmation() {
    if (confirm("Are you sure you want to delete this user?")) {
            __doPostBack(btnUserDelete, '');
    }

    return false;
 }

And none of them works.

Answer 1

Try this:

function Confirm() {
    var confirm_value = document.createElement("INPUT");
    confirm_value.type = "hidden";
    confirm_value.name = "confirm_value";

        if (confirm("Your asking")) {
            confirm_value.value = "Yes";
            document.forms[0].appendChild(confirm_value);
        }
    else {
        confirm_value.value = "No";
        document.forms[0].appendChild(confirm_value);
    }
}

In Button call function:

<asp:Button ID="btnReprocessar" runat="server" Text="Reprocessar" Height="20px" OnClick="btnReprocessar_Click" OnClientClick="Confirm()"/>

In class .cs call method:

        protected void btnReprocessar_Click(object sender, EventArgs e)
    {
        string confirmValue = Request.Form["confirm_value"];
        if (confirmValue == "Yes")
        {

        }
    }

Answer 2

try this :

<asp:Button runat="server" ID="btnUserDelete" Text="Delete" CssClass="GreenLightButton" 
   onClientClick=" return confirm('Are you sure you want to delete this user?')" 
   OnClick="BtnUserDelete_Click"  meta:resourcekey="BtnUserDeleteResource1"  />

Answer 3

Try this:

<asp:Button runat="server" ID="btnDelete" Text="Delete"
   onClientClick="javascript:return confirm('Are you sure you want to delete this user?');" OnClick="BtnDelete_Click" />

Answer 4

try this : OnClientClick="return confirm('Are you sure ?');" Also set : CausesValidation="False"

Answer 5

This is a simple way to do client-side validation BEFORE the confirmation. It makes use of the built in ASP.NET validation javascript.

<script type="text/javascript">
    function validateAndConfirm() {
        Page_ClientValidate("GroupName");  //'GroupName' is the ValidationGroup
        if (Page_IsValid) {
            return confirm("Are you sure?");
        }
        return false;
    }
</script>

<asp:TextBox ID="IntegerTextBox" runat="server" Width="100px" MaxLength="6" />
<asp:RequiredFieldValidator ID="reqIntegerTextBox" runat="server" ErrorMessage="Required"
    ValidationGroup="GroupName"  ControlToValidate="IntegerTextBox" />
<asp:RangeValidator ID="rangeTextBox" runat="server" ErrorMessage="Invalid"
    ValidationGroup="GroupName" Type="Integer" ControlToValidate="IntegerTextBox" />
<asp:Button ID="SubmitButton" runat="server" Text="Submit"  ValidationGroup="GroupName"
    OnClick="SubmitButton_OnClick" OnClientClick="return validateAndConfirm();" />

Source: Client Side Validation using ASP.Net Validator Controls from Javascript

Answer 6

You can put the above answers into one line like this. And you don't need to write the function.

    <asp:Button runat="server" ID="btnUserDelete" Text="Delete" CssClass="GreenLightButton"
         OnClick="BtnUserDelete_Click" meta:resourcekey="BtnUserDeleteResource1"
OnClientClick="if ( !confirm('Are you sure you want to delete this user?')) return false;"  />