My AJAX button needs to update some CSS, but I'm facing a challenge. The controls I want to modify are in a separate file and cannot be relocated.
The CSS that needs updating is in the Site.master file within this panel:
<asp:ScriptManager ID="ScriptManager" runat="server" />
<asp:UpdatePanel ID="Panel2" runat="server" updatemode="Always">
<ContentTemplate>
<div id="updateThis" runat="server"><p>Test text</p></div>
</ContentTemplate>
</asp:UpdatePanel>
Meanwhile, the button for triggering the update is located in the Items.ascx file:
<asp:UpdateProgress runat="server" ID="PageUpdateProgress">
<ProgressTemplate>
<img class="ajax-loader" src="/Images/ajax-loader.gif" alt="Loading..." />
</ProgressTemplate>
</asp:UpdateProgress>
<asp:UpdatePanel ID="Panel3" runat="server" updatemode="Conditional">
<Triggers>
<asp:AsyncPostBackTrigger controlid="UpdateButton" eventname="Click" />
</Triggers>
<ContentTemplate>
<asp:Button runat="server" OnClick="UpdateButton"
OnClientClick="hideButton()" Text="Update"
class="update" ID="UpdateButton" name="UpdateButton"
type="submit" ></asp:Button>
</ContentTemplate>
</asp:UpdatePanel>
This is the method UpdateButton inside Items.ascx.cs:
protected void UpdateButton(object sender, EventArgs e)
{
var masterPage = this.Page.Master;
var updatePanel = masterPage.FindControl("Panel2");
var div = (HtmlGenericControl)updatePanel.Controls[0].FindControl("updateThis");
div.Style.Add("color", "#ff0000");
}
Upon clicking the button, the CSS does not update as expected. Currently, the AJAX UpdateProgress template shows the loading GIF briefly, then the GIF disappears without any color change in the text.
EDIT
To troubleshoot further, consider the following:
THIS WORKS
protected void UpdateButton(object sender, EventArgs e)
{
var masterPage = this.Page.Master;
var updatePanel = masterPage.FindControl("Panel2");
var div = (HtmlGenericControl)updatePanel.FindControl("updateThis");
div.Style.Add("color", "#ff0000");
UpdateButton.Text = "Done!";
}
An error was identified where #updateThis was used in FindControl(). Learn from my mistake!