How do I make a Textbox Postback on KeyUp?
I have a Textbox that changes the content of a dropdown in the OnTextChanged event. This event seems to fire when the textbox loses focus. How do I make this happen on the keypress or keyup event?
Here is an example of my code
<asp:TextBox ID="Code" runat="server" AutoPostBack="true" OnTextChanged="Code_TextChanged">
<asp:UpdatePanel ID="Update" runat="server">
<ContentTemplate>
<asp:DropDownList runat="server" ID="DateList" />
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="Code" />
</Triggers>
</asp:UpdatePanel>
So in the codebehind, I bind the dropdown on page load. The Code_TextChanged event just rebinds the dropdown. I would like this to happen on each keypress rather than when the textbox loses focus.
I inherited this code recently and this is not the ideal method of doing this for me, but time limitations prevent me from rewriting this in a web servicy method.
I have tried using jQuery to bind the "keyup" event to match the "change" event for the textbox, but this only works on the first key pressed.
Answer
This will solve your problem. Logic is same as the solution suggested by Kyle.
Have a look at this.
<head runat="server">
<title></title>
<script type="text/javascript">
function RefreshUpdatePanel() {
__doPostBack('<%= Code.ClientID %>', '');
};
</script>
<asp:TextBox ID="Code" runat="server" onkeyup="RefreshUpdatePanel();" AutoPostBack="true" OnTextChanged="Code_TextChanged"></asp:TextBox>
<asp:UpdatePanel ID="Update" runat="server">
<ContentTemplate>
<asp:DropDownList runat="server" ID="DateList" />
<asp:TextBox runat="server" ID="CurrentTime" ></asp:TextBox>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="Code" />
</Triggers>
</asp:UpdatePanel>
Code behind goes like this...
protected void Code_TextChanged(object sender, EventArgs e)
{
//Adding current time (minutes and seconds) into dropdownlist
DateList.Items.Insert(0, new ListItem(DateTime.Now.ToString("mm:ss")));
//Setting current time (minutes and seconds) into textbox
CurrentTime.Text = DateTime.Now.ToString("mm:ss");
}
I have added additional textbox to see change in action, do remove the textbox.