How to Capture Function Keys in WebForms? - vb.net

Question

I have very little experience of working with VB.NET Web Application.
I would like to know how to capture function keys (F1, F2... F12) in a "VB WebForms applications (Web Application)".
I have been searching on search engines and even here on stackoverflow but I kept getting results full of VB.NET Windows Forms which showed examples of _keydown event like
Private Sub xyz_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles Me.KeyDown
I tried looking into my WebForm's different event like Form's event, TextBox's event etc. but couldn't find it anywhere. So I assume these are available for Windows Forms ONLY.
What I am trying to do is as follows -
In a TextBox when the user presses F1 key, open a new form which has a Gridview with some data
The user clicks on one row and the value(s) (one or more) of this row is captured in variable(s) and the form should close and control should come back to TextBox with the captured row data.
Also how can I setFocus on any particular row of TextBox?
Can someone please give me a small example of how this can be done.

Answer 1

You can't capture it on the server side, but maybe you could try this:
<script type="text/javascript">
$(document).on("keypress", function (e) {
var code = e.which;
if (code == 123) { // The F12 Key
$.ajax({
type: "POST",
url: "YourCallingPage.aspx/OpenForm",
contentType: "application/json; charset=utf-8",
dataType: "json"
});
}
});
</script>
Then in the codebehind of YourCallingPage.aspx(what ever page the textbox is on) add the following method(or whatever you name the method):
<System.Web.Services.WebMethod()> _
Public Shared Sub OpenForm()
HttpContext.Current.Response.Redirect("FormThatHasGrid.aspx")
End Sub
Now once you redirect back to YourCallingPage.aspx I guess you could append the selected grid value to the query string and populate the textbox like that, or some other method, but this is just a quick and dirty idea that may work for you.