I am interested in vb and am confused how to save the contents of a Picturebox as a png file when button1 is clicked. When I try to do it now, it produces the error I show below. I can't figure out how to fix this because I'm new to using visual basic. The debugger seemed to catch something but I can't make sense of it. I would be extremely pleased if someone would help me to fix this. Here is the code:
'*** Acknowlegements ***
'Ideas for this code came from the MicroSoft "Scribble" sample code,
'Christian Graus's excellent arcticle on a C++ code called "Doodle"
'and the MicroSoft website.
'By John Buettner
'26 July 2003
Imports System
Imports System.Drawing
Imports System.Windows.Forms
Public Class Form
'Namespace myPaint
Inherits System.Windows.Forms.Form ' Of course ;)
Dim mousePath As New System.Drawing.Drawing2D.GraphicsPath() 'declare a new Graphic path to follow the mouse movement
'*** below I declare some values for an Alpha and other user selected variables
'these will be used as I expand this program for a higher level use.
Dim myAlpha As Integer = 100 ' declare a Alpha variable
Dim myUserColor As New Color() 'this is a color the user selects
Friend WithEvents Button1 As Button
Friend WithEvents SaveFileDialog1 As SaveFileDialog
Dim myPenWidth As Single = 5 'set pen width variable
'**************************************************************
#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
Friend WithEvents PictureBox1 As System.Windows.Forms.PictureBox
<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
Dim resources As System.ComponentModel.ComponentResourceManager = New System.ComponentModel.ComponentResourceManager(GetType(Form))
Me.PictureBox1 = New System.Windows.Forms.PictureBox()
Me.Button1 = New System.Windows.Forms.Button()
Me.SaveFileDialog1 = New System.Windows.Forms.SaveFileDialog()
CType(Me.PictureBox1, System.ComponentModel.ISupportInitialize).BeginInit()
Me.SuspendLayout()
'
'PictureBox1
'
Me.PictureBox1.BackColor = System.Drawing.Color.GhostWhite
Me.PictureBox1.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D
Me.PictureBox1.Location = New System.Drawing.Point(0, 33)
Me.PictureBox1.Name = "PictureBox1"
Me.PictureBox1.Size = New System.Drawing.Size(696, 423)
Me.PictureBox1.TabIndex = 2
Me.PictureBox1.TabStop = False
'
'Button1
'
Me.Button1.Image = Global.Ubernote.My.Resources.Resources.fl
Me.Button1.ImageAlign = System.Drawing.ContentAlignment.MiddleLeft
Me.Button1.Location = New System.Drawing.Point(12, 4)
Me.Button1.Name = "Button1"
Me.Button1.Size = New System.Drawing.Size(75, 23)
Me.Button1.TabIndex = 3
Me.Button1.Text = "Save"
Me.Button1.UseVisualStyleBackColor = True
'
'SaveFileDialog1
'
'
'Form
'
Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
Me.BackColor = System.Drawing.Color.White
Me.ClientSize = New System.Drawing.Size(696, 456)
Me.Controls.Add(Me.Button1)
Me.Controls.Add(Me.PictureBox1)
Me.Icon = CType(resources.GetObject("$this.Icon"), System.Drawing.Icon)
Me.Name = "Form"
Me.Text = "Draw"
CType(Me.PictureBox1, System.ComponentModel.ISupportInitialize).EndInit()
Me.ResumeLayout(False)
End Sub
#End Region
Private Sub PictureBox1_MouseDown(ByVal sender As Object, ByVal e As MouseEventArgs) Handles PictureBox1.MouseDown
If e.Button = MouseButtons.Left Then ' draw a filled circle if left mouse is down
mousePath.StartFigure() ' The L mouse is down so we need to start a new line in mousePath
End If
End Sub
Private Sub PictureBox1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseMove
If e.Button = MouseButtons.Left Then ' draw a filled circle if left mouse is down
Try
mousePath.AddLine(e.X, e.Y, e.X, e.Y) 'Add mouse coordiantes to mousePath
Catch
MsgBox("No way, Hose!")
End Try
End If
PictureBox1.Invalidate() 'Repaint the PictureBox using the PictureBox1 Paint event
End Sub
Private Sub PictureBox1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles PictureBox1.Paint
' Here is where we do the actual painting
Try ' error trapping
myUserColor = (System.Drawing.Color.Black) 'You can remove this line and add a user selected color to
'change the value of myUserColor
myAlpha = 100 ' This will give the color a Alpha effect, you can set this to 255 if you want a full color
Dim CurrentPen = New Pen(Color.FromArgb(myAlpha, myUserColor), myPenWidth) 'Set up the pen
e.Graphics.DrawPath(CurrentPen, mousePath) 'draw the path! :)
Catch
End Try
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Try
SaveFileDialog1.ShowDialog()
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
Private Sub SaveFileDialog1_FileOk(sender As Object, e As System.ComponentModel.CancelEventArgs) Handles SaveFileDialog1.FileOk
Try
' Dim FileToSaveAs As String = System.IO.Path.Combine(My.Computer.FileSystem.SpecialDirectories.Temp, SaveFileDialog1.FileName)
' PictureBox1.Image.Save(FileToSaveAs, System.Drawing.Imaging.ImageFormat.Jpeg)
'PictureBox1.Image.Save(FileToSaveAs)
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
End Class
