"prof_martin" <profmar***@discussions.microsoft.com> wrote in message
news:13213B26-66C7-4C72-8004-13D0AB56E5F1@microsoft.com...
> Hi, I got problem, kindly please help. Thank you
>
> error message:
> An unhandled exception of type 'System.NullReferenceException' occurred in
> Test.exe
> Additional information: Object reference not set to an instance of an
> object.
>
> with following code:
> ---------------------------------------------------------------------------------
> Public Class Form2
>    Inherits System.Windows.Forms.Form
>
> #Region " Windows Form Designer generated code "
>
>    Public Sub New()
>        MyBase.New()
>
>        'This call is required by the Windows Form Designer.
>        InitializeComponent()
>
>        'Add any initialization after the InitializeComponent() call
>
>    End Sub
>
>    'Form overrides dispose to clean up the component list.
>    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
>        If disposing Then
>            If Not (components Is Nothing) Then
>                components.Dispose()
>            End If
>        End If
>        MyBase.Dispose(disposing)
>    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.
>    Friend WithEvents PictureBox1 As System.Windows.Forms.PictureBox
>    Friend WithEvents Button1 As System.Windows.Forms.Button
>    <System.Diagnostics.DebuggerStepThrough()> Private Sub
> InitializeComponent()
>        Me.PictureBox1 = New System.Windows.Forms.PictureBox
>        Me.Button1 = New System.Windows.Forms.Button
>        Me.SuspendLayout()
>        '
>        'PictureBox1
>        '
>        Me.PictureBox1.BackColor = System.Drawing.SystemColors.Window
>        Me.PictureBox1.Location = New System.Drawing.Point(40, 48)
>        Me.PictureBox1.Name = "PictureBox1"
>        Me.PictureBox1.Size = New System.Drawing.Size(256, 192)
>        Me.PictureBox1.TabIndex = 0
>        Me.PictureBox1.TabStop = False
>        '
>        'Button1
>        '
>        Me.Button1.Location = New System.Drawing.Point(32, 264)
>        Me.Button1.Name = "Button1"
>        Me.Button1.TabIndex = 1
>        Me.Button1.Text = "Button1"
>        '
>        'Form2
>        '
>        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
>        Me.ClientSize = New System.Drawing.Size(416, 357)
>        Me.Controls.Add(Me.Button1)
>        Me.Controls.Add(Me.PictureBox1)
>        Me.Name = "Form2"
>        Me.Text = "Form2"
>        Me.ResumeLayout(False)
>
>    End Sub
>
> #End Region
>
>    Private Sub PictureBox1_Paint(ByVal sender As Object, ByVal e As
> System.Windows.Forms.PaintEventArgs) Handles PictureBox1.Paint
>        Dim g As Graphics = e.Graphics
>        g.DrawLine(New Drawing.Pen(Color.Red), 1, 1, 200, 200)
>    End Sub
>
>    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
> System.EventArgs) Handles Button1.Click
>        PictureBox1.Image.Save("c:\test.gif")
>    End Sub
> End Class
> ---------------------------------------------------------------------------------

"Kevin Spencer" wrote:

> You have not assigned an Image instance to the Image property of the
> PictureBox. All you have done is to override the OnPaint method. The Image
> property is null.
>
> --
> HTH,
>
> Kevin Spencer
> Microsoft MVP
> Bit Player
> http://unclechutney.blogspot.com
>
> Where there's a Will, there's a William.
>
> "prof_martin" <profmar***@discussions.microsoft.com> wrote in message
> news:13213B26-66C7-4C72-8004-13D0AB56E5F1@microsoft.com...
> > Hi, I got problem, kindly please help. Thank you
> >
> > error message:
> > An unhandled exception of type 'System.NullReferenceException' occurred in
> > Test.exe
> > Additional information: Object reference not set to an instance of an
> > object.
> >
> > with following code:
> > ---------------------------------------------------------------------------------
> > Public Class Form2
> >    Inherits System.Windows.Forms.Form
> >
> > #Region " Windows Form Designer generated code "
> >
> >    Public Sub New()
> >        MyBase.New()
> >
> >        'This call is required by the Windows Form Designer.
> >        InitializeComponent()
> >
> >        'Add any initialization after the InitializeComponent() call
> >
> >    End Sub
> >
> >    'Form overrides dispose to clean up the component list.
> >    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
> >        If disposing Then
> >            If Not (components Is Nothing) Then
> >                components.Dispose()
> >            End If
> >        End If
> >        MyBase.Dispose(disposing)
> >    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.
> >    Friend WithEvents PictureBox1 As System.Windows.Forms.PictureBox
> >    Friend WithEvents Button1 As System.Windows.Forms.Button
> >    <System.Diagnostics.DebuggerStepThrough()> Private Sub
> > InitializeComponent()
> >        Me.PictureBox1 = New System.Windows.Forms.PictureBox
> >        Me.Button1 = New System.Windows.Forms.Button
> >        Me.SuspendLayout()
> >        '
> >        'PictureBox1
> >        '
> >        Me.PictureBox1.BackColor = System.Drawing.SystemColors.Window
> >        Me.PictureBox1.Location = New System.Drawing.Point(40, 48)
> >        Me.PictureBox1.Name = "PictureBox1"
> >        Me.PictureBox1.Size = New System.Drawing.Size(256, 192)
> >        Me.PictureBox1.TabIndex = 0
> >        Me.PictureBox1.TabStop = False
> >        '
> >        'Button1
> >        '
> >        Me.Button1.Location = New System.Drawing.Point(32, 264)
> >        Me.Button1.Name = "Button1"
> >        Me.Button1.TabIndex = 1
> >        Me.Button1.Text = "Button1"
> >        '
> >        'Form2
> >        '
> >        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
> >        Me.ClientSize = New System.Drawing.Size(416, 357)
> >        Me.Controls.Add(Me.Button1)
> >        Me.Controls.Add(Me.PictureBox1)
> >        Me.Name = "Form2"
> >        Me.Text = "Form2"
> >        Me.ResumeLayout(False)
> >
> >    End Sub
> >
> > #End Region
> >
> >    Private Sub PictureBox1_Paint(ByVal sender As Object, ByVal e As
> > System.Windows.Forms.PaintEventArgs) Handles PictureBox1.Paint
> >        Dim g As Graphics = e.Graphics
> >        g.DrawLine(New Drawing.Pen(Color.Red), 1, 1, 200, 200)
> >    End Sub
> >
> >    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
> > System.EventArgs) Handles Button1.Click
> >        PictureBox1.Image.Save("c:\test.gif")
> >    End Sub
> > End Class
> > ---------------------------------------------------------------------------------
>
>