从背后的代码触发JavaScript Confirm（）

Question

I am working on a Asp.Net application, currently i am trying to trigger a JavaScript Confirm() popup from the code behind. I would like to popup without clicking any button_click event.

IF not blnResult then

popup message with OK& CANCEL

IF OK THEN Exit Sub

ELSE

no display

END IF 

I tried to do below things and it's not firing popup, please assist.

1) Created a button in ASPX

<asp:Button ID="btnConfirm" runat="server" Text="Delete-All" OnClick="btnConfirm_Click" OnClientClick="Confirm()"/>

JavaScript function

<script language="javascript" type = "text/javascript">
    function Confirm() {
        var confirm_value1 = document.createElement("INPUT");
        confirm_value1.type = "hidden";
        confirm_value1.name = "confirm_value";
        if (confirm("Do you want to delete all records?")) {
            confirm_value1.value = "Yes";
        } else {
            confirm_value1.value = "No";
        }
        document.forms[0].appendChild(confirm_value1);
    }
</script>

Code behind,

Public function GetConfirmation()

btnConfirm_Click(btnConfirm, EventArgs.Empty)

End Sub

Above line isn't firing the popup for me.

Answer 1

Just modify your javascript function.

<script language="javascript" type = "text/javascript">
    function Confirm() {
        var confirm_value1 = document.createElement("INPUT");
        confirm_value1.type = "hidden";
        confirm_value1.name = "confirm_value";
        if (confirm("Do you want to delete all records?")) {
            confirm_value1.value = "Yes";
        } else {
            confirm_value1.value = "No";
        }
        document.forms[0].appendChild(confirm_value1);

        return false;//this will prevent submit click.
    } </script>

just add return statement at last line of function.

return false;

I hope this solution will help you.

Answer 2

If I have understood correctly then probably you want to call your code behind click event only when user confirms by click on yes. There are many of ways doing this. I have listed few of them. Choose which ever suits best for you.

Don't know why you have created a hidden input field. What is the purpose of creating it. In case you don't need hidden input filed you can try these out.

1. Confirmation in HTML Tag

<asp:Button ID="btnConfirm" runat="server" Text="Delete-All" OnClick="btnConfirm_Click" OnClientClick="return confirm('Do you want to delete all records?');"/>

2. Confirmation in JavaScript

<asp:Button ID="btnConfirm" runat="server" Text="Delete-All" OnClick="btnConfirm_Click" OnClientClick="Confirm();"/>

---

<script language="javascript" type="text/javascript">
    function Confirm() {
        return confirm("Do you want to delete all records?");
    }
</script>

Or

<script language="javascript" type="text/javascript">
    function Confirm() {
        var result = confirm("Do you want to delete all records?");    
        return result;
    }
</script>

If you do need to keep hidden input field then use below.

<script language="javascript" type="text/javascript">
    function Confirm() {
        var confirm_value1 = document.createElement("INPUT");
        confirm_value1.type = "hidden";
        confirm_value1.name = "confirm_value";

        var result = confirm("Do you want to delete all records?");    
        confirm_value1.value = result ? "Yes" : "No";    
        document.forms[0].appendChild(confirm_value1);    
        return result;    
    }
</script>