Some graphics

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Some graphics
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Projects included

• A slideshow
• a dark moon moving
• phases of the moon
• billiards
• Your own icons and bitmaps
• Pie chart

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Timer pictures

• Using a timer, you can create a slideshow.
• Set the timer to some interval enable, and
  start the timer in formload
• Also, put some picture into a picturebox.
• Count mod the number of pictures.
• For example, if there are 8 pictures, count mod 8
  in your timer code. The timer code needs to also
  change the picture

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Timer

• The timer may be covered in another (later?)
  slideshow.
• You add a timer to a project from the toolbox.
• It does not go on your application like most
  controls we have used.
• Like a printer-capability, a timer goes in the
  component tray, an area displayed under your
  design view.

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Timer

• You must enable the timer to let it start
  clicking, or disable it to turn it off.
• You must set the timing interval (in milli
  seconds)
• You must start or stop the timer.
• Instructions to do these things must appear in an
  appropriate place in your code.
• Starting the timer might go in formload, or a
  buttonhandler for start slideshow or new
  Slideshow.
• Stopping the timer might go in a button handler
  for stop slideshow

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Timer

• Heres code to start the timer clicking every 1
  second
• Timer1.Interval 1000 1 sec
• Timer1.Enabled True
• Timer1.Start() start it

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The slideshow code formload

• Private Sub Form1_Load(ByVal sender As
  System.Object, ByVal e As System.EventArgs)
  Handles MyBase.Load
• Timer1.Interval 1000 1 sec
• Timer1.Enabled True
• Timer1.Start() start it
• PictureBox1.Image Image.FromFile("C\"
  names(picnum) ".jpg") load first picture
• End Sub

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The timer-tick sub event handler

• The timer tick sub handles what you wish to do
  each time the timer ticks.
• This might be to move an image on a panel or a
  picturebox on an application or load/display a
  new image in a picture box, or several of the
  above instructions.
• A common way to cycle around a set of images is
  to get the next one mod picturecount If there
  are 4 pictures named pic0.jpg, pic1.jpg,pic2.jpg,p
  ic3.jpg then
• Picbox.imageimage.fromfile(p\pic num
  .jpg)
• would get another picture from the p drive. Num
  must be incremented mod 4.
• The pictures will all need to be the same type
  (jpg, gif, bmp, whatever).

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The slideshow code timer tick sub

• Dim picnum As Integer 0
• Dim names() As String "dog", "tish",
  "keely", "shan" a bunch of picnames
• Dim piclen As Integer names.Length
• Private Sub Timer1_Tick(ByVal sender As
  System.Object, ByVal e As System.EventArgs)
  Handles Timer1.Tick
• picnum (picnum 1) Mod piclen
• PictureBox1.Image Image.FromFile("C\"
  names(picnum) ".jpg")
• End Sub

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Moving things

• We have already learned how to display a picture
  on the screen using a picture box and setting the
  image by selection, or retrieving the image at
  run time using a file name.
• We also used a timer object in our microwave
  simulation.
• We can put the two pieces together to make
  something move across the screen.
• The x coordinate will measure in from the left
  on your form, y will measure down from the top,
  a sort of flipped over 1st quadrant of the
  cartesian coordinate plane.

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components

• Put a picture box in your form and set its image
  to one of the moon icons. (I found these in
  Visual Studio.Net\common7\graphics\elements but
  any image will do.
• Add a timer control to your component tray by
  double clicking this control from the toolbox.
• Timers (and printers, too, for example) are not
  visible components, so they go into a component
  tray and are manipulated programmed from there.

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Timer tick code

• Private Sub Timer1_Tick(ByVal sender As
  System.Object, ByVal e As System.EventArgs)
  Handles Timer1.Tick
• Static xint As Integer PictureBox1.Left
• Static yint As Integer PictureBox1.Top
• Static widthint As Integer
  PictureBox1.Width
• Static heightint As Integer
  PictureBox1.Height
• With Me
• xint - 10
• If xint lt 0 Then
• xint .Width
• End If
• .PictureBox1.SetBounds(xint, yint,
  widthint, heightint)
• End With
• End Sub

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Timer tick code

• The code picturebox.setbounds moves the picture
  box as the timer ticks. I decrement the x
  (measure of distance in from left) value to move
  the moon to the left.
• When it gets to 0 (zero) I start in again from
  the right.
• Code form load as follows
• Private Sub form1_Load(ByVal sender As
  System.Object, ByVal e As System.EventArgs)
  Handles MyBase.Load
• Timer1.Enabled True
• Timer1.Start()
• End Sub

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The moons phases a moon that moves
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Now lets simulate phases of the moon
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Phases of the moon
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Phases of the moon

• I found 8 moon icons (moon01 to moon08).
• I have a counter declared globally
• Each time the timer clicks I count mod 8 and add
  1, yeilding an integer 18
• Then I set the picture box image to the
  particular image. (moon0 count .ico)
• Remember, in debug, you need a bin in front of
  the name.

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Heres my new timer tick code

• Dim filename As String
• Static xint As Integer PictureBox1.Left
• Static yint As Integer PictureBox1.Top
• Static widthint As Integer
  PictureBox1.Width
• Static heightint As Integer
  PictureBox1.Height
• With Me
• xint - 10
• If xint lt 0 Then
• xint .Width
• End If
• .PictureBox1.SetBounds(xint, yint,
  widthint, heightint)
• ' filename Directory.GetCurrentDirec
  tory "moon0" count ".ico"
• 'filename filename.Substring(3)
• .PictureBox1.Image
  Image.FromFile(Directory.GetCurrentDirectory
  "moon0" count ".ico")
• count (count 1) Mod 8 1
• End With

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Some exercises

• You can make the image move faster or slower by
  changing the amount you add to the xint or by
  changing the timer tick interval.
• You can make it move up (or down) by using the y
  value.
• How about making a billiard ball bounce around
  the form?

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Bouncing an image around the form

• If you define an fixed value to increment the x
  and y coordinates of your picture, you can create
  an effect like bouncing against walls.
• Whenever the x coordinate of the topleft of the
  picturebox is less than zero, flip the increment
  values sign.
• Do the same if the x coord gets too big.
• Ditto for the y coordinates.

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Assuming xint, yint, xinc and yint are all
defined

• This code flips a sign
• xinc-xinc
• You can get or set your forms width. It will
  start at 0 and go to some value.
• Similar for the height.
• This code checks if xint is a legal value for a 0
  by 300 width form
• If xint lt 0 Or xint xinc gt 300 Then
• xinc -xinc
• xint xinc
• End If
• Xint, yint, xinc and yinc are all filed values
  and need to be initialized at compile time or in
  formload

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Heres timer code to bounce a picture (assuming
fixed form size 300X300)

• Static xint As Integer PictureBox1.Left
• Static yint As Integer PictureBox1.Top
• Static widthint As Integer
  PictureBox1.Width
• Static heightint As Integer
  PictureBox1.Height
• With Me
• xint xinc
• yint yinc
• If xint lt 0 Or xint xinc gt 300
  Then
• xinc -xinc
• xint xinc
• End If
• If yint lt 0 Or yint yinc gt 300
  Then
• yinc -yinc
• yint yinc
• End If
• .PictureBox1.SetBounds(xint, yint,
  widthint, heightint)
• End With

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Your own icon or bitmap

• You can create your own icon files for use in vb
  projects

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Your own icons
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Under project select add new item, then select
bitmap, icon or whatever
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draw your icon or bitmap and save it
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Then select it from your picturebox/properties/ima
ge dialog
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A Pie chart
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Pie chart

• Refresh method calls (form) paint event
• Pie chart requires you pick the circle center and
  each color
• You determine the start angle and sweep angle of
  each section (for a total of 360 degrees)

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Pie chart- form paint

• Private Sub Form1_Paint(ByVal sender As Object,
  ByVal e As System.Windows.Forms.PaintEventArgs)
  Handles MyBase.Paint
• Dim xcent, ycent As Integer
• xcent 140
• ycent 180
• With Me
• .CreateGraphics.FillPie(Brushes.Blue,
  xcent, ycent, 100, 100, 0, 50)
• .CreateGraphics.FillPie(Brushes.Red,
  xcent, ycent, 100, 100, 50, 30)
• .CreateGraphics.FillPie(Brushes.Green,
  xcent, ycent, 100, 100, 80, 70)
• .CreateGraphics.FillPie(Brushes.Beige,
  xcent, ycent, 100, 100, 150, 90)
• .CreateGraphics.FillPie(Brushes.Coral,
  xcent, ycent, 100, 100, 240, 120) 'start angle,
  sweep angle
• End With
• End Sub