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.netgdi+argumentexception

In GDI+ a "Parameter is not valid." on setting pen.Width

I have a System.Drawing.Pen _pen.

When in some iterations is setting _pen.Width = 3 it gives me:

System.ArgumentException 
  Message="Parameter is not valid."
  Source="System.Drawing"  - System.Drawing.dll
  StackTrace:
       at System.Drawing.Pen.set_Width(Single value)
       at MyProject.ctlPanneauGraphique.CustomLine.set_BorderWidth(Int32 value) in 
       ....
       at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run(String[] commandLine)
       at MySolution.My.MyApplication.Main(String[] Args) in 17d14f5c-a337-4978-8281-53493378c1071.vb:line 81
       at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)
       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()

What and why?

Solution

  • Are you disposing the _pen variable?

    If not, this may indicate a resource leak problem as you have suspected.

    If yes, this may indicate that you are accessing a disposed instance. GDI objects often throw ArgumentException when used after they have been disposed.