Hi Friends,

I am trying to create a very simple counter on a webpage with the click of a button:

    protected void Button1_Click(object sender, EventArgs e)
    {
        for (Int32 i = 0; i <= 100; i++)
        {
            Label1.Text = Convert.ToString(i);
            System.Threading.Thread.Sleep(100);
            <Update/refresh the UpdatePenal Here>
        }
    }

I have a updatepanel which contains this Label and Button controls. I want after every increment the label should actually show the current value on the webpage.

I tried to use linkbutton as trigger with update mode conditional. Even with code to fire the linkbutton.click in the above for loop the page is not refresing after each increment.

Please help
 

Hi,

have Tried using Update() method in Update panle..

protected void Button1_Click(object sender, EventArgs e)
    {
        for (Int32 i = 0; i <= 100; i++)
        {
            Label1.Text = Convert.ToString(i);
            System.Threading.Thread.Sleep(100);
           UpdatePanel_Id.Update();          

        }
    }

i have tried update() for updatepanel but it is not working, any idea? 

Are you expecting to see the textbox increment from 0 to 100, gradually?  If so, the code you have won't do it.  It is only after ALL of the code in the code behind has executed that the page is rendered, or partially rendered.  In your case, you are probably seeing 0, and then when you click the button, 100.

to update the onclick event you would have to add your label to your UpdatePanel_Id ContentContainer

UpdatePanel_Id.ContentTemplateContainer.Controls.Add(Label1)

 set update panel UpdateMode = Conditional

How UpdatePanel Controls Are Refreshed

The following list describes the property settings of the UpdatePanel control that determine when a panel's content is updated during partial-page rendering.

• If the UpdateMode property is set to Always, the UpdatePanel control’s content is updated on every postback that originates from anywhere on the page. This includes asynchronous postbacks from controls that are inside other UpdatePanel controls, and postbacks from controls that are not inside UpdatePanel controls.

• If the UpdateMode property is set to Conditional, the UpdatePanel control’s content is updated when one of the following is true:

  • When the postback is caused by a trigger for that UpdatePanel control.

  • When you explicitly call the UpdatePanel control's Update() method.

  • When the UpdatePanel control is nested inside another UpdatePanel control and the parent panel is updated.

  • When the ChildrenAsTriggers property is set to true and any child control of the UpdatePanel control causes a postback. Child controls of nested UpdatePanel controls do not cause an update to the outer UpdatePanel control unless they are explicitly defined as triggers for the parent panel.

AlohaMora:

i have tried update() for updatepanel but it is not working, any idea? 

Any error???

I am not getting any error. Just the label is not refreshing. Please see the aspx and aspx.cs codes below:

            <asp:ScriptManager ID="ScriptManager1" runat="server">
            </asp:ScriptManager> 
           
            <asp:UpdatePanel ID="UpdatePanel1" UpdateMode="Conditional" runat="server">
                <ContentTemplate>                    
                    Count:
                    <asp:Label ID="Label1" runat="server" Text=""></asp:Label><br />
                    <br />
                    <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Start" />
                </ContentTemplate>
            </asp:UpdatePanel>

    protected void Page_Load(object sender, EventArgs e)
    {
        Label1.Text = string.Empty;   
    }

    protected void Button1_Click(object sender, EventArgs e)
    {
        for (Int32 i = 0; i <= 100; i++)
        {
            Label1.Text = Convert.ToString(i);
            System.Threading.Thread.Sleep(100);
            UpdatePanel1.Update();
        }
    }

Hi,

Label1.Text = string.Empty;  

Remove this Line rom onload ..

Or

 keep in Condition of ispostback== false

I removed this line from Page_load still not working.

    protected void Page_Load(object sender, EventArgs e)
    {
        //Label1.Text = string.Empty;   
    }

    protected void Button1_Click(object sender, EventArgs e)
    {
        for (Int32 i = 0; i <= 100; i++)
        {
            Label1.Text = Convert.ToString(i);
            System.Threading.Thread.Sleep(100);
            UpdatePanel1.Update();
        }
    }

Read my previous note.

MetalAsp.Net:

Read my previous note.

He is right..

Thanks Guys for your reply.

@ MetalAsp.Net

I have read your previous note, Yes on te button click i only see 100.

But I want the label to show 1 2 3 ......... 100

i have tried the triggers also, puting the linkbutton as a trigger and firing the click even in the for loop which didn't work.

any help?

You might make use of a Timer that triggers an async postback every second, and increment the value of the TB by 1 in the Tick event.

My preferred way of doing counter like this is using javascript, client-side, making use of the setInterval() function.  Don't know if it's the best way, or if it works in your situation...