Question

I have this Scroll event of a trackBar:

private void trackBar1_Scroll(object sender, EventArgs e)
        {

                trackbarCounter++;
                if (manualDone == true)
                {
                    myTrackPanelss1.trackBar1.Minimum = 0;
                    myTrackPanelss1.trackBar1.Maximum = _fi.Length - 1;                    setpicture(myTrackPanelss1.trackBar1.Value);
                    this.pictureBox1.Refresh();
                }
                if (automaticDone == true)
                {
                    myTrackPanelss1.trackBar1.Minimum = 0;
                    myTrackPanelss1.trackBar1.Maximum = fiAutomatic.Length - 1;
                    long[] tt = list_of_histograms[myTrackPanelss1.trackBar1.Value];
                    long res = GetTopLumAmount(tt, 1000);
                    long max = GetHistogramMaximum(tt);
                    GetHistogramAverage(tt);
                    setpicture(myTrackPanelss1.trackBar1.Value);
                    this.pictureBox1.Refresh();

                                    }

        }

The exception is on this line:

long[] tt = list_of_histograms[myTrackPanelss1.trackBar1.Value];

After im clicking on the trackBar and move it to the right in this case this time it went as far as to the frame/track 40 then throw the exception there.

The exception:

Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index

Now fiAutomatic variable contain 2225 indexs for example in index [0] i see: {000001.bmp}
In index [1] i see: {000002.bmp}
And so on.

list_of_histograms is a contain now 40 indexs in each index i have a 256 indexs inside for example in index[0] i see: {[long256]} and i see in index[0] 256 numbers.
Then in index[1] again {[long256]} and another 256 numbers and so on.

And the trackBar value is 40.

But why when im moving the trackBar to the right after 40 frames/images its throwing this exception ?

This is the full exception message:

System.ArgumentOutOfRangeException was unhandled
  Message=Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index
  Source=mscorlib
  ParamName=index
  StackTrace:
       at System.ThrowHelper.ThrowArgumentOutOfRangeException()
       at System.Collections.Generic.List`1.get_Item(Int32 index)
       at Extracting_Frames.Form1.trackBar1_Scroll(Object sender, EventArgs e) in D:\C-Sharp\Extracting_Frames\Extracting_Frames\Extracting_Frames\Form1.cs:line 1793
       at System.Windows.Forms.TrackBar.OnScroll(EventArgs e)
       at System.Windows.Forms.TrackBar.WndProc(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
       at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
       at System.Windows.Forms.UnsafeNativeMethods.SendMessage(HandleRef hWnd, Int32 msg, IntPtr wParam, IntPtr lParam)
       at System.Windows.Forms.Control.SendMessage(Int32 msg, IntPtr wparam, IntPtr lparam)
       at System.Windows.Forms.Control.ReflectMessageInternal(IntPtr hWnd, Message& m)
       at System.Windows.Forms.Control.WndProc(Message& m)
       at System.Windows.Forms.ScrollableControl.WmHScroll(Message& m)
       at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
       at System.Windows.Forms.UserControl.WndProc(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
       at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
       at System.Windows.Forms.UnsafeNativeMethods.CallWindowProc(IntPtr wndProc, IntPtr hWnd, Int32 msg, IntPtr wParam, IntPtr lParam)
       at System.Windows.Forms.NativeWindow.DefWndProc(Message& m)
       at System.Windows.Forms.Control.DefWndProc(Message& m)
       at System.Windows.Forms.Control.WndProc(Message& m)
       at System.Windows.Forms.TrackBar.WndProc(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
       at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
       at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
       at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
       at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
       at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
       at System.Windows.Forms.Application.Run(Form mainForm)
       at Extracting_Frames.Program.Main() in D:\C-Sharp\Extracting_Frames\Extracting_Frames\Extracting_Frames\Program.cs:line 18
       at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       at System.AppDomain.nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       at System.Runtime.Hosting.ManifestRunner.Run(Boolean checkAptModel)
       at System.Runtime.Hosting.ManifestRunner.ExecuteAsAssembly()
       at System.Runtime.Hosting.ApplicationActivator.CreateInstance(ActivationContext activationContext, String[] activationCustomData)
       at System.Runtime.Hosting.ApplicationActivator.CreateInstance(ActivationContext activationContext)
       at System.Activator.CreateInstance(ActivationContext activationContext)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssemblyDebugInZone()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException: 

Answer 1

list_of_histograms is a contain now 40 indexs in each index

This would be your problem. Remember that when you declare something, it indexes it from 0. So 40 indexes would mean it maxes out at 39. Doing list_of_histograms[40] is going to cause an error.

EDIT: And NOW I notice the comment on your question when I go to retag it…