Null reference error when adding picturebox dynamically to tabpage

Question

Getting the exception message:

Object Reference not set to an instance of an object.

My code is:

PictureBox myPicBox = new PictureBox();
myPicBox.Visible = true;
myPicBox.Image = Bitmap.FromFile(@"C:\Users\MyUser\Downloads\1341596825343s1jpg.jpg");
myPicBox.Dock = DockStyle.Fill;
this.MyTabPage.Controls.Add(myPicBox);

Where MyTabPage is the fourth page in a tab control. Any suggestions?

EDIT:

Stack Trace is Here

at ShipSiegeDashBoard.Form1.LoadSpaceStations() in C:\ShipSiegeTool\ShipSiegeDashBoard\Form1.cs:line 46 at ShipSiegeDashBoard.Form1..ctor() in C:\ShipSiegeTool\ShipSiegeDashBoard\Form1.cs:line 31 at ShipSiegeDashBoard.Program.Main() in C:\ShipSiegeTool\ShipSiegeDashBoard\Program.cs:line 18 at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args) at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
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()

Have you tried debugging it and narrowing it down to which line your exception comes from? You could even try posting your stack trace which would help as well. — Cheesebaron, Dec 25 '12 at 22:32
Is your code placed in Form's constructor before `InitializeComponent`? — Nick Hill, Dec 25 '12 at 22:36
Set a breakpoint on the line throwing the exception and hover your mouse pointer over the different parts of the statement. You will see what is `null`. — Olivier Jacot-Descombes, Dec 25 '12 at 22:47
Almost all cases of `NullReferenceException` are the same. Please see "[What is a NullReferenceException in .NET?](http://stackoverflow.com/questions/4660142/what-is-a-nullreferenceexception-in-net)" for some hints. — John Saunders, Dec 25 '12 at 22:52
It seems like you are getting a nullpointer exeption. Add a breakpoint to your code and check which variable is not set. It could be either your tabpage or it's controls. — user1574041, Dec 25 '12 at 22:34

score 1 · Accepted Answer · answered Dec 25 '12 at 22:49

1

I suppose your MyTabPage control isn't initialized yet. You should not try to use until after it has been initialized.

answered Dec 25 '12 at 22:49

comecme

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so I can add it to the form successfully, but not the tab page – Badmiral Dec 25 '12 at 22:52

Null reference error when adding picturebox dynamically to tabpage

1 Answers1