如何在点击事件之前通过javascript修改按钮的值？

Question

I need to modify value of my button via javascript and then, call click method.

 <script type="text/javascript">
        function callPagerButton(x)
        {                
            $("#btnPager").attr('value', x);
            $("#btnPager").prop('value', x);
            $("#btnPager").html(x);
            $("#btnPager").click();        
        }
    </script>

The problem here is that in sender parameter of click event, i cant see the changes made to the button via javascript: pageBtn.Attributes("value") = "Nothing" . Any ideas? I'm using ASPX

Protected Sub turnPage(ByVal sender As Object, ByVal e As EventArgs)

    Dim pageBtn = CType(sender, Button)

End Sub

Answer 1

Anything changed on the client-side won't be available on the server-side. Buttons only postback the value attribute IF the button triggered a postback to the server; with web forms, some button click actions are javascript-generated so that might cause a different behavior.

If you need to submit some piece of data to the server, I'd recommend add:

<asp:HiddenField id="hdn" runat="server" ClientIDMode="Static" />

Anything given to the hidden field's value attribute will be available on the server:

$("#hdn").val("TEST");

On server:

var txt = hdn.Value; //TEST