Question

First, I want to refer to this post, I think it’s the same problem:

http://social.msdn.microsoft.com/forums/en-us/MSWinWebChart/thread/B0594293-BB4B-4646-9CEF-8761AE02C005

I’ve got the following Code:

protected void LinkButton1_Click(object sender, EventArgs e)
{
  pnlTest.Controls.Add(GetChart());
  upnlTest.Update();
}

The chart simply isn’t shown.

The link at the top now tells me I have to add the chart control in the Page_Load or Pre_Load but how do I get the fact that “LinkButton1” caused the PostBack.

Additional problem: Within the event handler LinkButton1_Click some data is being generated and should be used as input parameters for the GetChart() method.

Maybe someone could help me out?

Answer 1

The solution lies in the Web.config. It requires adding the “POST” verb to the httpHandler.

Before:

 <system.web>
   <httpHandlers>
       <add verb="GET,HEAD" path="ChartImg.axd"
            type="System.Web.UI.DataVisualization.Charting.ChartHttpHandler,
            System.Web.DataVisualization, Version=4.0.0.0, Culture=neutral,
            PublicKeyToken=31bf3856ad364e35" />
   </httpHandlers>

After:

<system.web>
  <httpHandlers>
       <add verb="GET,HEAD,POST" path="ChartImg.axd"
            type="System.Web.UI.DataVisualization.Charting.ChartHttpHandler,
            System.Web.DataVisualization, Version=4.0.0.0, Culture=neutral,
            PublicKeyToken=31bf3856ad364e35" />
  </httpHandlers>