Drawing a line

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Drawing a line

How do I get a line drawing object into my toolbar

Answer this question

Drawing a line

  • Martin Smyth

    Not sure what you mean, but if you want to add a verticle line as a seperator between controls on a toolbar then you add a Seperator control.

    Or, are you talking about putting a button on the toolbar that when clicked allows the user to draw a line somewhere on the form You'd probably want to build a UserControl for drawing on the form...



  • Giber

    S_DS,

    There are a couple problems with this code that I want to point out.  Don't get me wrong, you've got some good examples of the math involved with plotting shapes by points (as opposed to drawing the shapes with the appropriate method).  But there are some issues with the way you do the drawing itself.

    Number one is that you're using the CreateGraphics method of the picturebox to do your drawing.  This is not desirable becuase any time the PictureBox is repainted, your drawing is lost.  For any GDI drawing to be permanent it must be done either in response to the control's Paint event, or better yet, in an override of the control's base OnPaint method.  This is why I suggested that the OP create a UserControl to do the drawing.

    Another big issue is that your calling the CreateGraphics() method using inline code.  This is a bad, bad, idea.  When you use inline code such as:

    picBoxOutput.CreateGraphics.DrawLine(m_Pen, x2, y2, x2 + 1, y2)

    You are not maintaining a reference to the Graphics object that is created; therefore you cannot call Dispose() on the object.  This can lead to unreleased GDI Objects that waste system resources.  Whenever you create a Graphics object, it should always have the Dispose() method called on it when your are finished.  You also should not create a Graphics object inside of a loop.  Delcare the Graphics object once outside the loop and then reuse it inside the loop.  Dispose of it when the loop finishes.

    Now, you may be thinking:  "But the GarbageCollector will clean up those Graphics objects if I don't dispose of them".  I thought the same thing but a long time ago there was a healthy forum discussion that proved that not disposing of Graphics objects causes wasted resources.



  • White Hawk

    Ooh! This is a No No!

    Never .Dispose a Graphics object unless you created it yourself. In this code the Paint method includes the Graphics object in the PaintEventArgs. You should not Dispose this object.

    Private Sub ToolStrip1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles ToolStrip1.Paint

    Dim g As Graphics = e.Graphics

    g.DrawLine(Pens.Black, 0, 200, 200, 0)

    g.Dispose() '<---------------REMOVE THIS LINE

    End Sub

  • Luminita

    Hi,

    Not sure on that one entirely but if you start with a code window in VB.Net and delete ALL of the code so you have an empty code window. The following code PASTED all at once will give you a working program. ;-)

    Then take a look at my graphics demo code which has some comments.

    The line command i have highlighted in ORANGE LIKE THIS

    I know you can draw directly on a form too as i learnt some of the graphics colour change stuff from another user on >>

    http://www.programmersheaven.com/c/MsgBoard/wwwboard.asp Board=39&src=20&Setting=

    '-----------------------------START OF CODE--------------------------------------------------------------

    Public Class Form1

    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 picBoxOutput As System.Windows.Forms.PictureBox

    Friend WithEvents btnDemo1 As System.Windows.Forms.Button

    Friend WithEvents btnDemo2 As System.Windows.Forms.Button

    Friend WithEvents btnDemo3 As System.Windows.Forms.Button

    Friend WithEvents btnDemo4 As System.Windows.Forms.Button

    Friend WithEvents btnDemo5 As System.Windows.Forms.Button

    Friend WithEvents btnDemo6 As System.Windows.Forms.Button

    Friend WithEvents btnDemo7 As System.Windows.Forms.Button

    Friend WithEvents btndemo8 As System.Windows.Forms.Button

    Friend WithEvents btndemo9 As System.Windows.Forms.Button

    Friend WithEvents btnExit As System.Windows.Forms.Button

    Friend WithEvents btnDemo10 As System.Windows.Forms.Button

    Friend WithEvents btnDemo11 As System.Windows.Forms.Button

    Friend WithEvents btnDemo12 As System.Windows.Forms.Button

    Friend WithEvents ColorDialog1 As System.Windows.Forms.ColorDialog

    Friend WithEvents txtColor As System.Windows.Forms.TextBox

    Friend WithEvents btnColorDialog As System.Windows.Forms.Button

    Friend WithEvents TrackBar1 As System.Windows.Forms.TrackBar

    Friend WithEvents TrackBar2 As System.Windows.Forms.TrackBar

    Friend WithEvents btnBackColour As System.Windows.Forms.Button

    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()

    Me.picBoxOutput = New System.Windows.Forms.PictureBox

    Me.btnExit = New System.Windows.Forms.Button

    Me.btnDemo1 = New System.Windows.Forms.Button

    Me.btnDemo2 = New System.Windows.Forms.Button

    Me.btnDemo3 = New System.Windows.Forms.Button

    Me.btnDemo4 = New System.Windows.Forms.Button

    Me.btnDemo5 = New System.Windows.Forms.Button

    Me.btnDemo6 = New System.Windows.Forms.Button

    Me.btnDemo7 = New System.Windows.Forms.Button

    Me.btndemo8 = New System.Windows.Forms.Button

    Me.btndemo9 = New System.Windows.Forms.Button

    Me.btnDemo10 = New System.Windows.Forms.Button

    Me.btnDemo11 = New System.Windows.Forms.Button

    Me.btnDemo12 = New System.Windows.Forms.Button

    Me.ColorDialog1 = New System.Windows.Forms.ColorDialog

    Me.txtColor = New System.Windows.Forms.TextBox

    Me.btnBackColour = New System.Windows.Forms.Button

    Me.btnColorDialog = New System.Windows.Forms.Button

    Me.TrackBar1 = New System.Windows.Forms.TrackBar

    Me.TrackBar2 = New System.Windows.Forms.TrackBar

    CType(Me.TrackBar1, System.ComponentModel.ISupportInitialize).BeginInit()

    CType(Me.TrackBar2, System.ComponentModel.ISupportInitialize).BeginInit()

    Me.SuspendLayout()

    '

    'picBoxOutput

    '

    Me.picBoxOutput.BackColor = System.Drawing.Color.Black

    Me.picBoxOutput.Location = New System.Drawing.Point(88, 8)

    Me.picBoxOutput.Name = "picBoxOutput"

    Me.picBoxOutput.Size = New System.Drawing.Size(780, 320)

    Me.picBoxOutput.TabIndex = 0

    Me.picBoxOutput.TabStop = False

    '

    'btnExit

    '

    Me.btnExit.BackColor = System.Drawing.Color.White

    Me.btnExit.Font = New System.Drawing.Font("Microsoft Sans Serif", 18.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))

    Me.btnExit.Location = New System.Drawing.Point(808, 384)

    Me.btnExit.Name = "btnExit"

    Me.btnExit.Size = New System.Drawing.Size(75, 40)

    Me.btnExit.TabIndex = 4

    Me.btnExit.Text = "Exit"

    '

    'btnDemo1

    '

    Me.btnDemo1.BackColor = System.Drawing.Color.White

    Me.btnDemo1.Font = New System.Drawing.Font("Microsoft Sans Serif", 18.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))

    Me.btnDemo1.Location = New System.Drawing.Point(16, 384)

    Me.btnDemo1.Name = "btnDemo1"

    Me.btnDemo1.Size = New System.Drawing.Size(104, 40)

    Me.btnDemo1.TabIndex = 5

    Me.btnDemo1.Text = "Circle."

    '

    'btnDemo2

    '

    Me.btnDemo2.BackColor = System.Drawing.Color.White

    Me.btnDemo2.Font = New System.Drawing.Font("Microsoft Sans Serif", 18.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))

    Me.btnDemo2.Location = New System.Drawing.Point(16, 432)

    Me.btnDemo2.Name = "btnDemo2"

    Me.btnDemo2.Size = New System.Drawing.Size(104, 40)

    Me.btnDemo2.TabIndex = 6

    Me.btnDemo2.Text = "Star."

    '

    'btnDemo3

    '

    Me.btnDemo3.BackColor = System.Drawing.Color.White

    Me.btnDemo3.Font = New System.Drawing.Font("Microsoft Sans Serif", 18.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))

    Me.btnDemo3.Location = New System.Drawing.Point(16, 488)

    Me.btnDemo3.Name = "btnDemo3"

    Me.btnDemo3.Size = New System.Drawing.Size(104, 40)

    Me.btnDemo3.TabIndex = 7

    Me.btnDemo3.Text = "Cone."

    '

    'btnDemo4

    '

    Me.btnDemo4.BackColor = System.Drawing.Color.White

    Me.btnDemo4.Font = New System.Drawing.Font("Microsoft Sans Serif", 18.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))

    Me.btnDemo4.Location = New System.Drawing.Point(128, 384)

    Me.btnDemo4.Name = "btnDemo4"

    Me.btnDemo4.Size = New System.Drawing.Size(232, 40)

    Me.btnDemo4.TabIndex = 8

    Me.btnDemo4.Text = "Clockwise spiral."

    '

    'btnDemo5

    '

    Me.btnDemo5.BackColor = System.Drawing.Color.White

    Me.btnDemo5.Font = New System.Drawing.Font("Microsoft Sans Serif", 18.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))

    Me.btnDemo5.Location = New System.Drawing.Point(128, 432)

    Me.btnDemo5.Name = "btnDemo5"

    Me.btnDemo5.Size = New System.Drawing.Size(232, 40)

    Me.btnDemo5.TabIndex = 9

    Me.btnDemo5.Text = "Anticlockwise spiral."

    '

    'btnDemo6

    '

    Me.btnDemo6.BackColor = System.Drawing.Color.White

    Me.btnDemo6.Font = New System.Drawing.Font("Microsoft Sans Serif", 18.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))

    Me.btnDemo6.Location = New System.Drawing.Point(128, 488)

    Me.btnDemo6.Name = "btnDemo6"

    Me.btnDemo6.Size = New System.Drawing.Size(112, 40)

    Me.btnDemo6.TabIndex = 10

    Me.btnDemo6.Text = "Ellipse1."

    '

    'btnDemo7

    '

    Me.btnDemo7.BackColor = System.Drawing.Color.White

    Me.btnDemo7.Font = New System.Drawing.Font("Microsoft Sans Serif", 18.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))

    Me.btnDemo7.Location = New System.Drawing.Point(128, 536)

    Me.btnDemo7.Name = "btnDemo7"

    Me.btnDemo7.Size = New System.Drawing.Size(112, 40)

    Me.btnDemo7.TabIndex = 11

    Me.btnDemo7.Text = "Ellipse2."

    '

    'btndemo8

    '

    Me.btndemo8.BackColor = System.Drawing.Color.White

    Me.btndemo8.Font = New System.Drawing.Font("Microsoft Sans Serif", 18.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))

    Me.btndemo8.Location = New System.Drawing.Point(248, 488)

    Me.btndemo8.Name = "btndemo8"

    Me.btndemo8.Size = New System.Drawing.Size(184, 40)

    Me.btndemo8.TabIndex = 12

    Me.btndemo8.Text = "Starry ellipse1."

    '

    'btndemo9

    '

    Me.btndemo9.BackColor = System.Drawing.Color.White

    Me.btndemo9.Font = New System.Drawing.Font("Microsoft Sans Serif", 18.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))

    Me.btndemo9.Location = New System.Drawing.Point(248, 536)

    Me.btndemo9.Name = "btndemo9"

    Me.btndemo9.Size = New System.Drawing.Size(184, 40)

    Me.btndemo9.TabIndex = 13

    Me.btndemo9.Text = "Starry ellipse2."

    '

    'btnDemo10

    '

    Me.btnDemo10.BackColor = System.Drawing.Color.White

    Me.btnDemo10.Font = New System.Drawing.Font("Microsoft Sans Serif", 18.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))

    Me.btnDemo10.Location = New System.Drawing.Point(368, 384)

    Me.btnDemo10.Name = "btnDemo10"

    Me.btnDemo10.Size = New System.Drawing.Size(232, 40)

    Me.btnDemo10.TabIndex = 14

    Me.btnDemo10.Text = "Clockwise shell."

    '

    'btnDemo11

    '

    Me.btnDemo11.BackColor = System.Drawing.Color.White

    Me.btnDemo11.Font = New System.Drawing.Font("Microsoft Sans Serif", 18.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))

    Me.btnDemo11.Location = New System.Drawing.Point(368, 432)

    Me.btnDemo11.Name = "btnDemo11"

    Me.btnDemo11.Size = New System.Drawing.Size(232, 40)

    Me.btnDemo11.TabIndex = 15

    Me.btnDemo11.Text = "Anticlockwise shell."

    '

    'btnDemo12

    '

    Me.btnDemo12.BackColor = System.Drawing.Color.White

    Me.btnDemo12.Font = New System.Drawing.Font("Microsoft Sans Serif", 18.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))

    Me.btnDemo12.Location = New System.Drawing.Point(616, 384)

    Me.btnDemo12.Name = "btnDemo12"

    Me.btnDemo12.Size = New System.Drawing.Size(120, 40)

    Me.btnDemo12.TabIndex = 16

    Me.btnDemo12.Text = "Polygon."

    '

    'txtColor

    '

    Me.txtColor.Location = New System.Drawing.Point(640, 432)

    Me.txtColor.Multiline = True

    Me.txtColor.Name = "txtColor"

    Me.txtColor.Size = New System.Drawing.Size(304, 40)

    Me.txtColor.TabIndex = 18

    Me.txtColor.Tag = "-1"

    Me.txtColor.Text = ""

    '

    'btnBackColour

    '

    Me.btnBackColour.BackColor = System.Drawing.Color.White

    Me.btnBackColour.Font = New System.Drawing.Font("Microsoft Sans Serif", 18.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))

    Me.btnBackColour.Location = New System.Drawing.Point(640, 528)

    Me.btnBackColour.Name = "btnBackColour"

    Me.btnBackColour.Size = New System.Drawing.Size(304, 40)

    Me.btnBackColour.TabIndex = 19

    Me.btnBackColour.Tag = "0"

    Me.btnBackColour.Text = "Select background colour."

    '

    'btnColorDialog

    '

    Me.btnColorDialog.BackColor = System.Drawing.Color.White

    Me.btnColorDialog.Font = New System.Drawing.Font("Microsoft Sans Serif", 18.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))

    Me.btnColorDialog.Location = New System.Drawing.Point(640, 480)

    Me.btnColorDialog.Name = "btnColorDialog"

    Me.btnColorDialog.Size = New System.Drawing.Size(304, 40)

    Me.btnColorDialog.TabIndex = 20

    Me.btnColorDialog.Text = "Select plot colour."

    '

    'TrackBar1

    '

    Me.TrackBar1.BackColor = System.Drawing.Color.DeepSkyBlue

    Me.TrackBar1.Location = New System.Drawing.Point(72, 336)

    Me.TrackBar1.Maximum = 780

    Me.TrackBar1.Name = "TrackBar1"

    Me.TrackBar1.Size = New System.Drawing.Size(808, 45)

    Me.TrackBar1.TabIndex = 21

    Me.TrackBar1.TickFrequency = 780

    Me.TrackBar1.TickStyle = System.Windows.Forms.TickStyle.Both

    Me.TrackBar1.Value = 180

    '

    'TrackBar2

    '

    Me.TrackBar2.BackColor = System.Drawing.Color.DeepSkyBlue

    Me.TrackBar2.Location = New System.Drawing.Point(888, 8)

    Me.TrackBar2.Maximum = 320

    Me.TrackBar2.Name = "TrackBar2"

    Me.TrackBar2.Orientation = System.Windows.Forms.Orientation.Vertical

    Me.TrackBar2.Size = New System.Drawing.Size(45, 336)

    Me.TrackBar2.TabIndex = 22

    Me.TrackBar2.TickFrequency = 320

    Me.TrackBar2.TickStyle = System.Windows.Forms.TickStyle.Both

    Me.TrackBar2.Value = 160

    '

    'Form1

    '

    Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)

    Me.BackColor = System.Drawing.Color.RoyalBlue

    Me.ClientSize = New System.Drawing.Size(952, 637)

    Me.Controls.Add(Me.TrackBar2)

    Me.Controls.Add(Me.TrackBar1)

    Me.Controls.Add(Me.txtColor)

    Me.Controls.Add(Me.btnColorDialog)

    Me.Controls.Add(Me.btnBackColour)

    Me.Controls.Add(Me.btnDemo12)

    Me.Controls.Add(Me.btnDemo11)

    Me.Controls.Add(Me.btnDemo10)

    Me.Controls.Add(Me.btndemo9)

    Me.Controls.Add(Me.btndemo8)

    Me.Controls.Add(Me.btnDemo7)

    Me.Controls.Add(Me.btnDemo6)

    Me.Controls.Add(Me.btnDemo5)

    Me.Controls.Add(Me.btnDemo4)

    Me.Controls.Add(Me.btnDemo3)

    Me.Controls.Add(Me.btnDemo2)

    Me.Controls.Add(Me.btnDemo1)

    Me.Controls.Add(Me.btnExit)

    Me.Controls.Add(Me.picBoxOutput)

    Me.Name = "Form1"

    Me.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen

    Me.Text = "Graphics demo."

    CType(Me.TrackBar1, System.ComponentModel.ISupportInitialize).EndInit()

    CType(Me.TrackBar2, System.ComponentModel.ISupportInitialize).EndInit()

    Me.ResumeLayout(False)

    End Sub

    #End Region

    Dim m_Pen As New Pen(Color.Black, 1)

    Dim m_GR As Graphics

    Dim v_color As Integer = -1

    Private Sub CLS()

    Dim myBrush As New SolidBrush(Color.Black)

    v_color = CInt(btnBackColour.Tag)

    myBrush.Color = ColorTranslator.FromHtml(v_color)

    'picBoxOutput.CreateGraphics.FillRectangle(myBrush, 0, 0, 780, 320)

    picBoxOutput.CreateGraphics.Clear(Color.FromArgb(v_color))

    End Sub

    Private Sub PlotCirc(ByVal X As Double, ByVal Y As Double, ByVal R As Double)

    'x1 and y1 are the centre coordinates of the circle.

    Dim x1 As Integer

    Dim y1 As Integer

    'x2 and y2 are the plotted positions that are calculated.

    Dim x2 As Integer

    Dim y2 As Integer

    Dim Radius As Double

    Dim PI As Double

    'Just a loop Count variable to go "2*PI radians"=360 degrees

    'for each circle loop.

    Dim Count As Double

    Dim blackBrush As New SolidBrush(Color.Black)

    x1 = TrackBar1.Value

    y1 = 320 - TrackBar2.Value

    Radius = R

    PI = Math.PI

    'In this example the circumference is divided by

    '10 and each point is then drawn to the centre.

    'Clear the screen after last "DEMO" button click.

    CLS()

    For Count = 0 To 2 * PI Step 0.05

    x2 = Math.Round(Radius * Math.Sin(Count) + x1, 3)

    y2 = Math.Round(Radius * Math.Cos(Count) + y1, 3)

    v_color = CInt(txtColor.Tag)

    m_Pen.Color = ColorTranslator.FromHtml(v_color)

    picBoxOutput.CreateGraphics.DrawLine(m_Pen, x2, y2, x2 + 1, y2)

    Next Count

    End Sub

    Private Sub btnDemo1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDemo1.Click

    PlotCirc(160, 160, 150)

    End Sub

    Private Sub btnDemo2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDemo2.Click

    'x1 and y1 are the centre coordinates of the circle.

    Dim x1 As Integer

    Dim y1 As Integer

    'x2 and y2 are the plotted positions that are calculated.

    Dim x2 As Integer

    Dim y2 As Integer

    Dim Radius As Double

    Dim PI As Double

    Dim convFactor As Double

    'Just a loop Count variable to go "2*PI radians"=360 degrees

    'for each circle loop.

    Dim Count As Double

    Dim blackBrush As New SolidBrush(Color.Black)

    '

    x1 = TrackBar1.Value

    y1 = 320 - TrackBar2.Value

    Radius = 150

    PI = Math.PI

    convFactor = 360 / (2 * PI)

    'In this example the circumference is divided by

    '30 and each point is then drawn to the centre.

    'Clear the screen after last "DEMO" button click.

    CLS()

    For Count = 0 To 360 / convFactor Step (360 / convFactor) / 30

    x2 = Math.Round(Radius * Math.Sin(Count) + x1, 3)

    y2 = Math.Round(Radius * Math.Cos(Count) + y1, 3)

    v_color = CInt(txtColor.Tag)

    m_Pen.Color = ColorTranslator.FromHtml(v_color)

    picBoxOutput.CreateGraphics.DrawLine(m_Pen, x2, y2, x1, y1)

    Next Count

    End Sub

    Private Sub btnDemo3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDemo3.Click

    'x1 and y1 are the centre coordinates of the circle.

    Dim x1 As Integer

    Dim y1 As Integer

    'x2 and y2 are the plotted positions that are calculated.

    Dim x2 As Integer

    Dim y2 As Integer

    Dim Radius As Double

    Dim PI As Double

    'Just a loop Count variable to go "2*PI radians"=360 degrees

    'for each circle loop.

    Dim Count As Double

    Dim blackBrush As New SolidBrush(Color.Black)

    x1 = TrackBar1.Value

    y1 = 320 - TrackBar2.Value

    Radius = 150

    PI = 355 / 113

    'In this example the circumference is divided by

    '50 and each point is then drawn to the point at 690,10

    'giving a cone effect.

    'Clear the screen after last "DEMO" button click.

    CLS()

    For Count = 0 To 2 * PI Step (2 * PI) / 50

    x2 = Math.Round(Radius * Math.Sin(Count) + x1, 3)

    y2 = Math.Round(Radius * Math.Cos(Count) + y1, 3)

    v_color = CInt(txtColor.Tag)

    m_Pen.Color = ColorTranslator.FromHtml(v_color)

    picBoxOutput.CreateGraphics.DrawLine(m_Pen, x2, y2, 400, 10)

    Next Count

    End Sub

    Private Sub btnDemo4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDemo4.Click

    'x1 and y1 are the centre coordinates of the circle.

    Dim x1 As Integer

    Dim y1 As Integer

    'x2 and y2 are the plotted positions that are calculated.

    Dim x2 As Integer

    Dim y2 As Integer

    Dim Radius As Double

    Dim PI As Double

    'Just a loop Count variable to go "2*PI radians"=360 degrees

    'for each circle loop.

    Dim Count As Double

    Dim blackBrush As New SolidBrush(Color.Black)

    x1 = TrackBar1.Value

    y1 = 320 - TrackBar2.Value

    Radius = 150

    PI = 355 / 113

    ' This is a maths method to plot lots of points joined together

    'to produce a spiral of 15 turns (31*PI)-PI=(30*PI) radians.

    'Note if you see the earlier examples. 2*PI= 360 degrees ( a full circle).

    'Clear the screen after last "DEMO" button click.

    CLS()

    ' The loop starts at PI value to start at 12 o'clock position otherwise

    'starting the loop at zero makes the graphic start at 6 o'clock.

    For Count = PI To 31 * PI Step 0.01

    'Note the step value in the FOR loop is = to the value at the

    'end of this radius reduction expression.

    'The following line gradually decreases the radius

    ' by 10 pixels on each loop.

    'Be careful here. You could use a While loop to check Radius is >=0

    'otherwise plotting heads back outwards!!

    Radius = Radius - (10 / ((2 * PI) / 0.01))

    'Forcing the X2 direction plot negative with the "-Radius" part here forces

    'plotting in a clockwise direction in relation to the Y2 value.

    x2 = Math.Round(-Radius * Math.Sin(Count) + x1, 3)

    y2 = Math.Round(Radius * Math.Cos(Count) + y1, 3)

    v_color = CInt(txtColor.Tag)

    m_Pen.Color = ColorTranslator.FromHtml(v_color)

    picBoxOutput.CreateGraphics.DrawLine(m_Pen, x2, y2, x2 + 1, y2 + 1)

    Next Count

    End Sub

    Private Sub btnDemo5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDemo5.Click

    'x1 and y1 are the centre coordinates of the circle.

    Dim x1 As Integer

    Dim y1 As Integer

    'x2 and y2 are the plotted positions that are calculated.

    Dim x2 As Integer

    Dim y2 As Integer

    Dim Radius As Double

    Dim PI As Double

    'Just a loop Count variable to go "2*PI radians"=360 degrees

    'for each circle loop.

    Dim Count As Double

    Dim blackBrush As New SolidBrush(Color.Black)

    x1 = TrackBar1.Value

    y1 = 320 - TrackBar2.Value

    Radius = 150

    PI = 355 / 113

    ' This is a maths method to plot lots of points joined together

    'to produce a spiral of 15 turns (31*PI)-PI=(30*PI) radians.

    'Note if you see the earlier examples. 2*PI= 360 degrees ( a full circle).

    'Clear the screen after last "DEMO" button click.

    CLS()

    ' The loop starts at PI value to start at 12 o'clock position otherwise

    'starting the loop at zero makes the graphic start at 6 o'clock.

    For Count = PI To 31 * PI Step 0.01

    'Note the step value in the FOR loop is = to the value at the

    'end of this radius reduction expression.

    'The following line gradually decreases the radius

    ' by 10 pixels on each loop.

    'Be careful here. You could use a While loop to check Radius is >=0

    'otherwise plotting heads back outwards!!

    Radius = Radius - (10 / ((2 * PI) / 0.01))

    'Forcing the X2 direction plot negative with the "-Radius" part here forces

    'plotting in a clockwise direction in relation to the Y2 value.

    x2 = Math.Round(Radius * Math.Sin(Count) + x1, 3)

    y2 = Math.Round(Radius * Math.Cos(Count) + y1, 3)

    v_color = CInt(txtColor.Tag)

    m_Pen.Color = ColorTranslator.FromHtml(v_color)

    picBoxOutput.CreateGraphics.DrawLine(m_Pen, x2, y2, x2 + 1, y2 + 1)

    Next Count

    End Sub

    Private Sub btnDemo6_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDemo6.Click

    'x1 and y1 are the centre coordinates of the circle.

    Dim x1 As Integer

    Dim y1 As Integer

    'x2 and y2 are the plotted positions that are calculated.

    Dim x2 As Integer

    Dim y2 As Integer

    Dim Radius As Double

    Dim PI As Double

    'Just a loop Count variable to go "2*PI radians"=360 degrees

    'for each circle loop.

    Dim Count As Double

    Dim blackBrush As New SolidBrush(Color.Black)

    x1 = TrackBar1.Value

    y1 = 320 - TrackBar2.Value

    Radius = 150

    PI = 355 / 113

    ' This is a maths method to plot lots of points on an ellipse circumference.

    'Ellipse is created by dividing y2 by 2. Please see 2nd line within the FOR<>NEXT

    'loop.

    'Clear the screen after last "DEMO" button click.

    CLS()

    For Count = 0 To 2 * PI Step 0.05

    x2 = Math.Round(Radius * Math.Sin(Count) + x1, 3)

    y2 = Math.Round(Radius / 2 * Math.Cos(Count) + y1, 3)

    v_color = CInt(txtColor.Tag)

    m_Pen.Color = ColorTranslator.FromHtml(v_color)

    picBoxOutput.CreateGraphics.DrawLine(m_Pen, x2, y2, x2 + 1, y2 + 1)

    Next Count

    End Sub

    Private Sub btnDemo7_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDemo7.Click

    'x1 and y1 are the centre coordinates of the circle.

    Dim x1 As Integer

    Dim y1 As Integer

    'x2 and y2 are the plotted positions that are calculated.

    Dim x2 As Integer

    Dim y2 As Integer

    Dim Radius As Double

    Dim PI As Double

    'Just a loop Count variable to go "2*PI radians"=360 degrees

    'for each circle loop.

    Dim Count As Double

    Dim blackBrush As New SolidBrush(Color.Black)

    x1 = TrackBar1.Value

    y1 = 320 - TrackBar2.Value

    Radius = 150

    PI = 355 / 113

    ' This is a maths method to plot lots of points on an ellipse circumference.

    'Ellipse is created by dividing y2 by 2. Please see 2nd line within the FOR<>NEXT

    'loop.

    'Clear the screen after last "DEMO" button click.

    CLS()

    For Count = 0 To 2 * PI Step 0.05

    x2 = Math.Round(Radius / 2 * Math.Sin(Count) + x1, 3)

    y2 = Math.Round(Radius * Math.Cos(Count) + y1, 3)

    v_color = CInt(txtColor.Tag)

    m_Pen.Color = ColorTranslator.FromHtml(v_color)

    picBoxOutput.CreateGraphics.DrawLine(m_Pen, x2, y2, x2 + 1, y2 + 1)

    Next Count

    End Sub

    Private Sub btndemo8_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btndemo8.Click

    'x1 and y1 are the centre coordinates of the circle.

    Dim x1 As Integer

    Dim y1 As Integer

    'x2 and y2 are the plotted positions that are calculated.

    Dim x2 As Integer

    Dim y2 As Integer

    Dim Radius As Double

    Dim PI As Double

    'Just a loop Count variable to go "2*PI radians"=360 degrees

    'for each circle loop.

    Dim Count As Double

    Dim blackBrush As New SolidBrush(Color.Black)

    x1 = TrackBar1.Value

    y1 = 320 - TrackBar2.Value

    Radius = 150

    PI = 355 / 113

    ' This is a maths method to plot lots of points on an ellipse circumference.

    'Ellipse is created bye dividing y2 by 2. Please see 2nd line within the FOR<>NEXT

    'loop.

    'Clear the screen after last "DEMO" button click.

    CLS()

    For Count = 0 To 2 * PI Step (2 * PI) / 40

    x2 = Math.Round(Radius * Math.Sin(Count) + x1, 3)

    y2 = Math.Round(Radius / 2 * Math.Cos(Count) + y1, 3)

    v_color = CInt(txtColor.Tag)

    m_Pen.Color = ColorTranslator.FromHtml(v_color)

    picBoxOutput.CreateGraphics.DrawLine(m_Pen, x2, y2, x1, y1)

    Next Count

    End Sub

    Private Sub btndemo9_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btndemo9.Click

    'x1 and y1 are the centre coordinates of the circle.

    Dim x1 As Integer

    Dim y1 As Integer

    'x2 and y2 are the plotted positions that are calculated.

    Dim x2 As Integer

    Dim y2 As Integer

    Dim Radius As Double

    Dim PI As Double

    'Just a loop Count variable to go "2*PI radians"=360 degrees

    'for each circle loop.

    Dim Count As Double

    Dim blackBrush As New SolidBrush(Color.Black)

    x1 = TrackBar1.Value

    y1 = 320 - TrackBar2.Value

    Radius = 150

    PI = 355 / 113

    ' This is a maths method to plot lots of points on an ellipse circumference.

    'Ellipse is created bye dividing y2 by 2. Please see 2nd line within the FOR<>NEXT

    'loop.

    'Clear the screen after last "DEMO" button click.

    CLS()

    For Count = 0 To 2 * PI Step (2 * PI) / 40

    x2 = Math.Round(Radius / 2 * Math.Sin(Count) + x1, 3)

    y2 = Math.Round(Radius * Math.Cos(Count) + y1, 3)

    v_color = CInt(txtColor.Tag)

    m_Pen.Color = ColorTranslator.FromHtml(v_color)

    picBoxOutput.CreateGraphics.DrawLine(m_Pen, x2, y2, x1, y1)

    Next Count

    End Sub

    Private Sub btnDemo10_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDemo10.Click

    'x1 and y1 are the centre coordinates of the circle.

    Dim x1 As Integer

    Dim y1 As Integer

    'x2 and y2 are the plotted positions that are calculated.

    Dim x2 As Integer

    Dim y2 As Integer

    Dim Radius As Double

    Dim PI As Double

    'Just a loop Count variable to go "2*PI radians"=360 degrees

    'for each circle loop.

    Dim Count As Double

    Dim blackBrush As New SolidBrush(Color.Black)

    x1 = TrackBar1.Value

    y1 = 320 - TrackBar2.Value

    Radius = 150

    PI = 355 / 113

    ' This is a maths method to plot lots of points joined together

    'to produce a spiral of 15 turns (31*PI)-PI=(30*PI) radians.

    'Note if you see the earlier examples. 2*PI= 360 degrees ( a full circle).

    'Clear the screen after last "DEMO" button click.

    CLS()

    ' The loop starts at PI value to start at 12 o'clock position otherwise

    'starting the loop at zero makes the graphic start at 6 o'clock.

    For Count = PI To 3 * PI Step 0.005

    'Note the step value in the FOR loop is = to the value at the

    'end of this radius reduction expression.

    'The following line gradually decreases the radius

    ' by 10 pixels on each loop.

    'Be careful here. You could use a While loop to check Radius is >=0

    'otherwise plotting heads back outwards!!

    Radius = Radius - (75 / ((2 * PI) / 0.005))

    'Forcing the X2 direction plot negative with the "-Radius" part here forces

    'plotting in a clockwise direction in relation to the Y2 value.

    x2 = Math.Round(-Radius * Math.Sin(Count) + x1, 3)

    y2 = Math.Round(Radius * Math.Cos(Count) + y1, 3)

    v_color = CInt(txtColor.Tag)

    m_Pen.Color = ColorTranslator.FromHtml(v_color)

    picBoxOutput.CreateGraphics.DrawLine(m_Pen, x2, y2, x1, y1)

    Next Count

    End Sub

    Private Sub btnDemo11_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDemo11.Click

    'x1 and y1 are the centre coordinates of the circle.

    Dim x1 As Integer

    Dim y1 As Integer

    'x2 and y2 are the plotted positions that are calculated.

    Dim x2 As Integer

    Dim y2 As Integer

    Dim Radius As Double

    Dim PI As Double

    'Just a loop Count variable to go "2*PI radians"=360 degrees

    'for each circle loop.

    Dim Count As Double

    Dim blackBrush As New SolidBrush(Color.Black)

    x1 = TrackBar1.Value

    y1 = 320 - TrackBar2.Value

    Radius = 150

    PI = 355 / 113

    ' This is a maths method to plot lots of points joined together

    'to produce a spiral of 15 turns (31*PI)-PI=(30*PI) radians.

    'Note if you see the earlier examples. 2*PI= 360 degrees ( a full circle).

    'Clear the screen after last "DEMO" button click.

    CLS()

    ' The loop starts at PI value to start at 12 o'clock position otherwise

    'starting the loop at zero makes the graphic start at 6 o'clock.

    For Count = PI To 3 * PI Step 0.005

    'Note the step value in the FOR loop is = to the value at the

    'end of this radius reduction expression.

    'The following line gradually decreases the radius

    ' by 10 pixels on each loop.

    'Be careful here. You could use a While loop to check Radius is >=0

    'otherwise plotting heads back outwards!!

    Radius = Radius - (75 / ((2 * PI) / 0.005))

    x2 = Math.Round(Radius * Math.Sin(Count) + x1, 3)

    y2 = Math.Round(Radius * Math.Cos(Count) + y1, 3)

    v_color = CInt(txtColor.Tag)

    m_Pen.Color = ColorTranslator.FromHtml(v_color)

    picBoxOutput.CreateGraphics.DrawLine(m_Pen, x2, y2, x1, y1)

    Next Count

    End Sub

    Private Sub btnDemo12_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDemo12.Click

    'x1 and y1 are the centre coordinates of the circle.

    Dim x1 As Integer

    Dim y1 As Integer

    'x2 and y2 are the plotted positions that are calculated.

    Dim x2 As Integer

    Dim y2 As Integer

    Dim Radius As Double

    Dim PI As Double

    'Just a loop Count variable to go "2*PI radians"=360 degrees

    'for each circle loop.

    Dim Count As Double

    Dim blackBrush As New SolidBrush(Color.Black)

    x1 = TrackBar1.Value

    y1 = 320 - TrackBar2.Value

    Radius = 160

    PI = 355 / 113

    'Clear the screen after last "DEMO" button click.

    CLS()

    Dim Pen1 As New Pen(Color.Blue, 1)

    x1 = Math.Round(Radius * Math.Sin(0) + x1, 3) - Radius

    For Count = 0 To 2 * PI Step (2 * PI) / 10

    x2 = Math.Round(Radius * Math.Sin(Count) + x1, 3)

    y2 = Math.Round(Radius * Math.Cos(Count) + y1, 3)

    ' Create array of points that define lines to draw.

    Dim points As PointF() = {New PointF(x2, y2), _

    New PointF(x1, y1)}

    'Draw lines to screen.

    v_color = CInt(txtColor.Tag)

    m_Pen.Color = ColorTranslator.FromHtml(v_color)

    picBoxOutput.CreateGraphics.DrawLines(m_Pen, points)

    x1 = x2

    y1 = y2

    Next Count

    End Sub

    Private Sub btnExit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnExit.Click

    End

    End Sub

    Private Sub btnColorDialog_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnColorDialog.Click

    Me.ColorDialog1.ShowDialog()

    txtColor.Text = Me.ColorDialog1.Color.ToString

    txtColor.Tag = Me.ColorDialog1.Color.ToArgb

    End Sub

    Private Sub btnBackColour_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnBackColour.Click

    Me.ColorDialog1.ShowDialog()

    txtColor.Text = Me.ColorDialog1.Color.ToString

    btnBackColour.Tag = Me.ColorDialog1.Color.ToArgb

    End Sub

    Private Sub draw1(ByVal v_Color As Integer)

    Dim m_GR = picBoxOutput.CreateGraphics

    m_Pen.Color = ColorTranslator.FromHtml(v_Color)

    m_GR.DrawLine(m_Pen, 20, 30, 800, 30)

    End Sub

    Private Sub TrackBar1_Scroll(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TrackBar1.Scroll

    TrackBar1.SmallChange = 1

    TrackBar1.SetRange(0, 780)

    End Sub

    Private Sub TrackBar2_Scroll(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TrackBar2.Scroll

    TrackBar2.SmallChange = 1

    TrackBar2.SetRange(0, 320)

    End Sub

    End Class

    '-----------------------------END OF CODE------------------------------------------

    Regards,

    S_DS.



  • A__alex10

    Use the paint event of your toolbar...

    Private Sub ToolStrip1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles ToolStrip1.Paint

    Dim g As Graphics = e.Graphics

    g.DrawLine(Pens.Black, 0, 200, 200, 0)

    End Sub



  • Drawing a line
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