Exception in c#

Question

Hi,

Iam getting the exception as mentioned below. Can u pls solve this issue.

A first chance exception of type 'System.InvalidCastException' occurred in App9.exe

'App9.exe' (Managed (v4.0.30319)): Loaded 'C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Diagnostics.Debug\v4.0_4.0.0.0__b03f5f7f11d50a3a\System.Diagnostics.Debug.dll'

Step into: Stepping over method without symbols 'System.Exception.ToString'

Code:

 private void textloaded(object sender, RoutedEventArgs e)  //Added tyhis function to access textblock in datatemplate.

        {

            TextBlock tb = (TextBlock)sender;

            tb.Visibility = Visibility.Visible;   //exception at this line.

        } 

        void dispatcherTimer_Tick(object sender, object e)

         {

          

            DateTimeOffset time = DateTimeOffset.Now;

            TimeSpan span = time - lastTime;

            lastTime = time;

           

            timesTicked++;

            if (timesTicked == 10)

            {

                RoutedEventArgs routedEventArgs = new RoutedEventArgs();

                textloaded(sender, routedEventArgs);

              

             }    

                    

                if (timesTicked > timesToTick)

                { 

                    stopTime = time;

                  

                    dispatcherTimer.Stop();

                   

                    span = stopTime - startTime;

                   

                }

        }

Thank you,

syamala.