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Visual Basic Example

Dear Sir,
Could you please give me a step by step walk thru' of how to run this code in Visual basic
Rgds,
Here is some code 
 
Add a 200x200 PictureBox (you can make it smaller or bigger but make it square) and a Label.
 
Drag in the inner blue circle to change the minutes.  Drag in the outer red circle to change the hour.
 
(...I have my angles going the opposite direction of what you wanted...)
 
Public Class Form1
 
    Private Const PI As Single = 3.141592654
 
    ' these two determine the clock position
    ' counterclockwise motion increases angle
    ' Valid values are 0 --> 359 (six degrees = one minute)
    ' up = 0
    ' left = 90
    ' down = 180
    ' right = 270
 
    ' Time = 3:55
    Private hourHand As Single = 270
    Private minuteHand As Single = 30
 
    ' these are the actual time values you can read from somewhere else
    ' like another form
    Public curHour As Integer
    Public curMinute As Integer
    Private curSecond As Integer
 
    Private clockFace As Bitmap
 
    Private Function DrawClockFace() As Bitmap
        Dim bmp As New Bitmap(PictureBox1.Width, PictureBox1.Height)
        Dim g As Graphics = Graphics.FromImage(bmp)
 
        Dim cx As Single, cy As Single
        Dim a As Integer
        Dim p As Point
        Dim s As Integer
 
        ' Compute the center of the PictureBox
        cx = PictureBox1.Width / 2
        cy = PictureBox1.Height / 2
 
        ' Clear the box
        g.Clear(PictureBox1.BackColor)
 
        ' Main Circle of the Clock
        Dim radius As Double = PictureBox1.Width * 0.8 / 2
        g.DrawEllipse(Pens.Black, New Rectangle(cx - radius, cy - radius, radius * 2, radius * 2))
 
        For a = 0 To 354 Step 6
            ' Minute Tick Marks
            p = getPoint(cx, cy, a, PictureBox1.Width * 0.6 / 2)
            g.DrawRectangle(Pens.Blue, New Rectangle(p.X, p.Y, 1, 1))
 
            If a Mod 30 = 0 Then
                ' Hour Tick Marks
                p = getPoint(cx, cy, a, PictureBox1.Width * 0.7 / 2)
                g.DrawRectangle(Pens.Red, New Rectangle(p.X, p.Y, 1, 1))
 
                ' Put the Hours (1 to 12) on the Clock Face
                p = getPoint(cx - 6, cy - 8, a, PictureBox1.Width * 0.9 / 2)
                s = 12 - a / 30
                If s = 0 Then
                    s = 12
                End If
                g.DrawString(s, Me.Font, Brushes.Black, p.X, p.Y)
            End If
        Next a
        g.Dispose()
 
        Return bmp
    End Function
 
    Private Sub PictureBox1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles PictureBox1.Paint
        If IsNothing(clockFace) Then
            clockFace = DrawClockFace()
            PictureBox1.Image = clockFace
        End If
 
        Dim cx As Single, cy As Single
        Dim p As Point
 
        cx = PictureBox1.Width / 2
        cy = PictureBox1.Height / 2
 
        p = getPoint(cx, cy, minuteHand, PictureBox1.Width * 0.58 / 2)
        e.Graphics.DrawLine(Pens.Blue, cx, cy, p.X, p.Y)
 
        p = getPoint(cx, cy, hourHand, PictureBox1.Width * 0.38 / 2)
        e.Graphics.DrawLine(Pens.Red, cx, cy, p.X, p.Y)
 
        curHour = 12 - (hourHand \ 30)
        If curHour = 0 Then
            curHour = 12
        End If
 
        curMinute = 60 - minuteHand \ 6
        If curMinute >= 60 Then
            curMinute = curMinute - 60
        End If
 
        Label1.Text = curHour & ":" & curMinute.ToString("00")
    End Sub
 
    Private Sub PictureBox1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseDown
        PictureBox1_MouseMove(sender, e)
    End Sub
 
    Private Sub PictureBox1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseMove
        Dim cx As Single, cy As Single
        Dim angle As Single
        Dim dist As Single
 
        If e.Button = Windows.Forms.MouseButtons.Left Then
            cx = PictureBox1.Width / 2
            cy = PictureBox1.Height / 2
 
            angle = getAngleInDegrees(cx, cy, e.X, e.Y)
            dist = getDistance(cx, cy, e.X, e.Y)
 
            If dist > PictureBox1.Width * 0.6 / 2 And dist < PictureBox1.Width * 0.8 / 2 Then
                hourHand = 360 - (angle \ 30) * 30 ' discrete jumps (note integer division)
                ' make it jump between hours at halfway point
                If angle Mod 30 > 15 Then
                    hourHand = hourHand - 30
                End If
                If hourHand = 360 Then
                    hourHand = 0
                End If
 
                PictureBox1.Refresh()
            ElseIf dist < PictureBox1.Width * 0.6 / 2 Then
                minuteHand = 360 - (angle \ 6) * 6 ' discrete jumps (note integer division)
                If angle Mod 6 >= 3 Then
                    minuteHand = minuteHand - 6
                End If
                If minuteHand = 360 Then
                    minuteHand = 0
                End If
 
                PictureBox1.Refresh()
            End If
        End If
    End Sub
 
    Private Function getDistance(ByVal Ax As Single, ByVal Ay As Single, ByVal Bx As Single, ByVal By As Single) As Single
        ' Pythagoreans Theorem
        getDistance = Math.Sqrt((Ax - Bx) * (Ax - Bx) + (Ay - By) * (Ay - By))
    End Function
 
    Private Function getPoint(ByVal cx As Single, ByVal cy As Single, ByVal angleInDegrees As Single, ByVal distance As Single) As Point
        Dim tp As Point
 
        ' angleInDegrees
        ' Valid values are 0 --> 359 (six degrees = one minute)
        ' draw a line from the center of the circle:
        ' 0 = up
        ' 90 = left
        ' 180 = down
        ' 270 = right
 
        ' Offset and Invert Angle then Convert Degrees to Radians
        angleInDegrees = -(angleInDegrees + 90) * PI / 180
 
        ' Compute the point that is at the specified angle from horizontal and
        ' at the specifed distance
        tp.X = cx + distance * Math.Cos(angleInDegrees)
        tp.Y = cy + distance * Math.Sin(angleInDegrees)
 
        Return tp
    End Function
 
    Private Function getAngleInDegrees(ByVal cx As Single, ByVal cy As Single, ByVal X As Single, ByVal Y As Single) As Single
        Dim dx As Single, dy As Single
        Dim angle As Single
 
        ' draw a line from the center of the circle
        ' to the where the cursor is...
        ' If the line points:
        ' up = 0 degrees
        ' right = 90 degrees
        ' down = 180 degrees
        ' left = 270 degrees
 
        dy = Y - cy
        dx = X - cx
        If dx = 0 Then
            ' Straight up and down cause div by zero error
            If dy <= 0 Then
                angle = 0
            Else
                angle = 180
            End If
        Else
            ' Compute Angle in Radians
            angle = Math.Atan(dy / dx)
            ' Convert to Degrees
            angle = angle * (180 / PI)
 
            ' Make it a number from 0 to 360 degrees
            If X > cx Then
                angle = 90 + angle
            Else
                angle = 270 + angle
            End If
        End If
 
        Return angle
    End Function
 
End Class

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0
sudarshantk
Asked:
sudarshantk
  • 2
1 Solution
 
Éric MoreauSenior .Net ConsultantCommented:
homework? EE is not a place where you can get your homework done. Work on it by yourself and come back with precise questions.
0
 
Mike TomlinsonMiddle School Assistant TeacherCommented:
That's not homework emoreau, it's some code I posted here:
http://www.experts-exchange.com/Programming/Languages/.NET/Visual_Basic.NET/Q_22016413.html

Here is what it produces:
AnalogClockExample.jpg
0
 
Mike TomlinsonMiddle School Assistant TeacherCommented:
What don't you get?...

It's really easy to setup:
(1) Create a New Project.
(2) Add a PictureBox Control (PictureBox1) and set its Size Property to 200,200.
(3) Add a Label (Label1).
(4) Press F7 to see the Code for the Form.
(5) Paste the Code I submitted over everything in the Code window.
(6) Run it by hitting F5.
(7) Drag Inside the BLUE dots to change the Minute hand.
(8) Drag Outside the BLUE dots (where the red dots are) to change the Hour hand.
(9) The selected time will appear in the Label.
0

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