[RESOLVED] Win32Exception out of nowhere.

[Troy Lundin]

I have been using this control for over a year now and suddenly it randomly causes exceptions. And by random, I mean I can rebuild the solution and the form with load correctly. Sometimes I have to rebuild two or three times, but eventually it will work properly. The stack trace is vague at best. This might be easier if the exception was consistent.

Here is the entire code of the control:

Imports System.ComponentModel
Imports System.Drawing
 
Public Class EditorForm
 
    Private _color As Color = Color.FromArgb(32, 40, 56)
    Private _font As Font = New Font("segoe ui", 8.5)
    Private _formBorderStyle As Windows.Forms.FormBorderStyle = Windows.Forms.FormBorderStyle.None
    Private _foreColor As Color = Color.FromArgb(128, 144, 160)
 
 
    <Browsable(True), DefaultValue(GetType(Color), "32, 40, 56"), DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)> _
    Overrides Property BackColor As Color
        Get
            Return _color
        End Get
        Set(value As Color)
            MyBase.BackColor = value
        End Set
    End Property
 
    <Browsable(True), DefaultValue(GetType(Color), "128, 144, 160"), DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)> _
    Overrides Property ForeColor As Color
        Get
            Return MyBase.ForeColor
        End Get
        Set(value As Color)
            If Not MyBase.ForeColor = value Then
                MyBase.ForeColor = value
                Invalidate()
            End If
        End Set
    End Property
 
    Sub New()
 
        ' This call is required by the designer.
        InitializeComponent()
 
        ' Add any initialization after the InitializeComponent() call.
        SetStyle(Windows.Forms.ControlStyles.OptimizedDoubleBuffer Or Windows.Forms.ControlStyles.SupportsTransparentBackColor Or Windows.Forms.ControlStyles.UserPaint, True)
        DoubleBuffered = True
 
        BackColor = _color
        ForeColor = _foreColor
 
        Font = _font
        FormBorderStyle = _formBorderStyle
    End Sub
 
End Class

<Global.Microsoft.VisualBasic.CompilerServices.DesignerGenerated()> _
Partial Class EditorForm
    Inherits System.Windows.Forms.Form
 
    'UserControl overrides dispose to clean up the component list.
    <System.Diagnostics.DebuggerNonUserCode()> _
    Protected Overrides Sub Dispose(ByVal disposing As Boolean)
        Try
            If disposing AndAlso components IsNot Nothing Then
                components.Dispose()
            End If
        Finally
            MyBase.Dispose(disposing)
        End Try
    End Sub
 
    'Required by the Windows Form Designer
    Private components As System.ComponentModel.IContainer
 
    'NOTE: The following procedure is required by the Windows Form Designer
    'It can be modified using the Windows Form Designer.  
    'Do not modify it using the code editor.
    <System.Diagnostics.DebuggerStepThrough()> _
    Private Sub InitializeComponent()
        Me.SuspendLayout()
        '
        'EditorForm
        '
        Me.BackColor = System.Drawing.Color.FromArgb(CType(CType(32, Byte), Integer), CType(CType(40, Byte), Integer), CType(CType(56, Byte), Integer))
        Me.ClientSize = New System.Drawing.Size(737, 590)
        Me.DoubleBuffered = True
        Me.Font = New System.Drawing.Font("Segoe UI", 8.5!)
        Me.ForeColor = System.Drawing.Color.FromArgb(CType(CType(128, Byte), Integer), CType(CType(144, Byte), Integer), CType(CType(160, Byte), Integer))
        Me.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None
        Me.Name = "EditorForm"
        Me.ResumeLayout(False)
 
    End Sub
 
End Class

Attached is a screencap I grabbed of the error.

[Shaggy Hiker]

That screen shot is too small/fuzzy to read any of the message, even when expanded. Perhaps you can copy the contents to a post.

[techgnome]

Or use WindowKey+S and select JUST the part where the error is... the forums here does fnky things with large images...

-tg

[ident]

400+ Posts you should know by now to explain your issue with out us having toi work out what you are doing.

[Niya]

400+ Posts you should know by now to explain your issue with out us having toi work out what you are doing.

Actually, I thought he explained it quite well.

I can't see anything wrong with the code though. I'd really like to see a better picture of that exception. I've run into designer problems like this numerous times when writing my own controls. The designer doesn't play well if you're not careful about bugs in your controls.

[Shaggy Hiker]

Or use WindowKey+S and select JUST the part where the error is... the forums here does fnky things with large images...

-tg

Yes, but sometimes the funky things on the forum are quite dexterous.

[Troy Lundin]

I apologize for the lack of visual representation in my original post. If I may, I would like to try again.

[Niya]

Apparently the designer cannot create the window for the Form. I tried your code and it worked fine for me as is so I don't know what the problem is. However, this is not really how you're supposed to derive from Form. Here is the proper way:-

Imports System.ComponentModel
 
'Prevents the Forms designer from loading
'as this Form is a base class from which your
'application's Forms can inherit, it's not meant to be designed upon
<ToolboxItem(False)> _
Public Class BlackComponent
    Inherits Component
End Class
 
Public Class EditorFormBase
    Inherits Form
 
    Private _color As Color = Color.FromArgb(32, 40, 56)
    Private _font As Font = New Font("segoe ui", 8.5)
    Private _formBorderStyle As Windows.Forms.FormBorderStyle = Windows.Forms.FormBorderStyle.None
    Private _foreColor As Color = Color.FromArgb(128, 144, 160)
 
 
    <Browsable(True), DefaultValue(GetType(Color), "32, 40, 56"), DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)> _
    Overrides Property BackColor As Color
        Get
            Return _color
        End Get
        Set(value As Color)
            MyBase.BackColor = value
        End Set
    End Property
 
    <Browsable(True), DefaultValue(GetType(Color), "128, 144, 160"), DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)> _
    Overrides Property ForeColor As Color
        Get
            Return MyBase.ForeColor
        End Get
        Set(value As Color)
            If Not MyBase.ForeColor = value Then
                MyBase.ForeColor = value
                Invalidate()
            End If
        End Set
    End Property
 
    Sub New()
 
        ' Add any initialization after the InitializeComponent() call.
        SetStyle(Windows.Forms.ControlStyles.OptimizedDoubleBuffer Or Windows.Forms.ControlStyles.SupportsTransparentBackColor Or Windows.Forms.ControlStyles.UserPaint, True)
        DoubleBuffered = True
 
        BackColor = _color
        ForeColor = _foreColor
 
        Font = _font
        FormBorderStyle = _formBorderStyle
    End Sub
 
 
 
 
 
End Class

I put the above in its own code file. When I need an editor form I simply inherit from EditorFormBase by changing the designer file for whatever Form I'm making.

[TnTinMN]

The only thing that I see as possibly suspicious, is the Invalidate call in in the ForeColor Set Method. I vaguely recall something about calls to such methods that are executed in constructors being a problem.

    Sub New()
         ' This call is required by the designer.
        InitializeComponent()
 
        ' Add any initialization after the InitializeComponent() call.
        SetStyle(Windows.Forms.ControlStyles.OptimizedDoubleBuffer Or Windows.Forms.ControlStyles.SupportsTransparentBackColor Or Windows.Forms.ControlStyles.UserPaint, True)
        DoubleBuffered = True
 
        BackColor = _color
        'ForeColor = _foreColor
        MyBase.ForeColor = _foreColor
 
        Font = _font
        FormBorderStyle = _formBorderStyle
    End Sub

Also, do you really want to return "_color" in the BackColor Get Method instead of MyBase.BackColor?

Are you using this as an Inherited Form? If so, why the designer code? Maybe its just a style preference, but the following makes more sense to me as the color and font setting will be done only once.

Imports System.ComponentModel
Imports System.Drawing
Public Class EditForm2
   Inherits Form
 
   Private Shared _color As Color = Color.FromArgb(32, 40, 56)
   Private Shared _font As Font = New Font("segoe ui", 8.5)
   Private Shared _formBorderStyle As Windows.Forms.FormBorderStyle = Windows.Forms.FormBorderStyle.None
   Private Shared _foreColor As Color = Color.FromArgb(128, 144, 160)
 
   Sub New()
      SetStyle(Windows.Forms.ControlStyles.OptimizedDoubleBuffer Or Windows.Forms.ControlStyles.SupportsTransparentBackColor Or Windows.Forms.ControlStyles.UserPaint, True)
      MyBase.DoubleBuffered = True
      MyBase.BackColor = _color
      MyBase.ForeColor = _foreColor
      MyBase.Font = _font
      MyBase.FormBorderStyle = _formBorderStyle
      MyBase.ClientSize = New System.Drawing.Size(737, 590)
   End Sub
 
 
   <Browsable(True), DefaultValue(GetType(Color), "32, 40, 56"), DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)> _
   Public Overrides Property BackColor() As Color
      Get
         Return MyBase.BackColor
         'Return _color
      End Get
      Set(ByVal value As Color)
          MyBase.BackColor = value
      End Set
   End Property
 
   <Browsable(True), DefaultValue(GetType(Color), "128, 144, 160"), DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)> _
   Overrides Property ForeColor() As Color
      Get
          Return MyBase.ForeColor
      End Get
      Set(ByVal value As Color)
          If Not MyBase.ForeColor = value Then
              MyBase.ForeColor = value
              Me.Invalidate()
          End If
      End Set
   End Property
End Class

[Troy Lundin]

Would I be correct in assuming the problems lies in the fact that the form has designer functionality, which apparently isn't needed?

[TnTinMN]

Would I be correct in assuming the problems lies in the fact that the form has designer functionality, which apparently isn't needed?

Possibly, yes but probably not.

Tracing the source of these types of errors (at least for me) often involves removing code until the error goes away and then trying to figure out why the offending statement is causing it.

The reason I mentioned the Invalidate method as a possible culprit is that it causes the control to be redrawn, but at the point in which it executed, the handle probably has not been created yet. So it is forcing creation at a non optimal time. I really do not have a firm enough grasp on these concepts myself to explain properly, so I will point you to this article for more info.

All About Handles in Windows Forms

To help us help you, please indicate what version of Visual Studio you are using and whether it is an Express (free, noncommercial) edition. The information may not be needed, but it can not hurt to provide it.

Edit:
P.S: In case it is not obvious, by setting MyBase.ForeColor the call to Invalidate in your overridden property is not called.

[Troy Lundin]

Microsoft Visual Studio Ultimate 2012 is what the About Dialog says.

The reason I was returning _color was for testing purposes, as MyBase gives me trouble sometimes. That was my error. I removed the Invalidate call, as well. The whole point of this class is to set default values so I don't have to set them manually each time I inherit the form.

What you say about invalidating during execution makes sense, but the error wasn't happening consistently. I could rebuild the solution two or three time and the error would stop. It seemed hit and miss. I haven't gotten the error since I made some changes, so I will mark as Solved for now.

Thank you for your help.