44
votes
protected void timer1_Tick(object sender, EventArgs e)
    {
        foreach (RepeaterItem item in rpChat.Items)
        {
            TextBox txt = item.FindControl("txtChatMessage") as TextBox;
            if (txt != null)
            {
                message[i] = txt.Text;
                i--;
            }
        }
        lblStatusChat.Text = "";
        RepeaterBind();
        string javaScript = "<script language=JavaScript>\n" + "alert('Button1_Click client-side');\n" + "</script>";

        Page.ClientScript.RegisterStartupScript(this.GetType(), "myKey", javaScript);
    }

timer_click trigggers and update panel. And the alert message doesnt show up on timer_tick event

4

4 Answers

113
votes

When you use an UpdatePanel, then you can not call JavaScript using ClientScript as you have tried to. You have to use ScriptManager.RegisterStartupScript instead.

So change your

Page.ClientScript.RegisterStartupScript(this.GetType(), "myKey", javaScript);

to

ScriptManager.RegisterStartupScript(updatePanelId,updatePanelId.GetType(), "alert", javaScript, true);
9
votes

You need to user ScriptManager class because you are register script when doing postback and using updatepanel

MSDN: ScriptManager.RegisterStartupScript

ScriptManager.RegisterStartupScript method used to add client script to a page when the control is wrapped inside an UpdatePanel.

ASPX page

<div>
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
    <ContentTemplate>
        <asp:Label ID="lblDisplayDate" runat="server" Text="Label"></asp:Label>
         <asp:Button ID="btnPostback" runat="server" onclick="btnPostback_Click" 
        Text="ClickMe" />
    </ContentTemplate>
</asp:UpdatePanel>
</div>

CodeBehind Register StartUp Script

protected void btnPostback_Click(object sender, EventArgs e)
{
    System.Text.StringBuilder sb = new System.Text.StringBuilder();
    sb.Append(@"<script language='javascript'>");
    sb.Append(@"var lbl = document.getElementById('lblDisplayDate');");
    sb.Append(@"lbl.style.color='red';");
    sb.Append(@"</script>");

    ScriptManager.RegisterStartupScript(btnPostback,this.GetType(), "JSCR", sb.ToString(),false);

}

Detail : Add JavaScript programmatically using RegisterStartupScript during an Asynchronous postback

9
votes

In my case ScriptManager.RegisterStartupScript didn't work too.

Not work:

ScriptManager.RegisterStartupScript(Me, 
  Me.GetType(), 
  String.Format("Data{0}", Me.ID), 
  "<script>alert(111);</script>", 
  False)

Work:

ScriptManager.RegisterStartupScript(Me.Page, 
  Me.GetType(), 
  String.Format("Data{0}", Me.ID), 
  "<script>alert(111);</script>", 
  False)

Me in the example is my custom control inherited from System.Web.UI.WebControls.WebParts.WebPart

2
votes

It must be un little bit later but I found the soluce here http://forums.asp.net/p/1117430/5483679.aspx/1

You have to use System.Web.UI.ScriptManager.RegisterClientScriptBlock instead of Page.ClientScript.RegisterStartupScript