SilentCodingOne
Member
I have an application that allows a user to choose a color and the width of the pen to draw with on the included panel. I have most it working properly except for a few remaining pieces. First whenever the user starts drawing the lines and panel visibly flicker and I cannot figure out how to resolve it. I tried things like doublebuffer but it did not work. It is probably something I did wrong as this is my first attempt at drawing in vb.net.
My second issue is that if you draw a line with one color and than switch to another color the previously drawn lines, etc. change to the new color. I want them to stay the same but cannot figure out how.
My last question is I can get the radiobuttons to work in terms showing only the correct one as checked. However the width of the pen does not change when used to draw. I was able to get it to change with the code below but it gets thinner instead of wider as the width listed gets higher plus like the color issue the width of previously drawn lines changes as well which it shouldn't
Below is the code I currently have
My second issue is that if you draw a line with one color and than switch to another color the previously drawn lines, etc. change to the new color. I want them to stay the same but cannot figure out how.
My last question is I can get the radiobuttons to work in terms showing only the correct one as checked. However the width of the pen does not change when used to draw. I was able to get it to change with the code below but it gets thinner instead of wider as the width listed gets higher plus like the color issue the width of previously drawn lines changes as well which it shouldn't
Below is the code I currently have
VB.NET:
Public Class frmDrawingPad
Dim index As Integer = 0 ' sets index for combobox control
Dim mousePath As New System.Drawing.Drawing2D.GraphicsPath()
Dim userColor As New Color() 'this is a color the user selects
Dim penWidth As Single
Dim rbChecked(3) As RadioButton
Private Sub ClearToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ClearToolStripMenuItem.Click
' calls procedure that clears panel
Call ClearDrawingPanel()
End Sub
Private Sub btnClear_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnClear.Click
' calls procedure that clears panel
Call ClearDrawingPanel()
End Sub
Private Sub panelDraw_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles panelDraw.MouseDown
If e.Button = MouseButtons.Left Then ' draw a filled line 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 panelDraw_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles panelDraw.MouseMove
If e.Button = MouseButtons.Left Then ' draw a filled cline 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
panelDraw.Invalidate()
End Sub
Private Sub panelDraw_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles panelDraw.Paint
Try ' error trapping
'*********************** NOTE ***********************************************
'The line below set the pen up with the ability to add user selected Alpha, Color and Penwidth
' A simpler, but less flexible solution would be to replace the line with the following code:
'Dim CurrentPen = New Pen(System.Drawing.Color.Black, myPenWidth)
'************ End Note ***************************
Dim CurrentPen = New Pen(userColor, penWidth) 'Set up the pen
e.Graphics.DrawPath(CurrentPen, mousePath) 'draw the path!
Catch
' MsgBox("Not happening!")
End Try
End Sub
Public Sub ClearDrawingPanel()
' clears drawing panel
Dim g As Graphics = panelDraw.CreateGraphics
g.Clear(panelDraw.BackColor)
mousePath.Reset()
g.Dispose()
End Sub
Private Sub frmDrawingPad_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
' loads list of colors to combobox
cboColorPick.Items.Add("Pick A Color")
cboColorPick.Items.Add("Black")
cboColorPick.Items.Add("Blue")
cboColorPick.Items.Add("Pink")
cboColorPick.Items.Add("Red")
cboColorPick.Items.Add("Green")
cboColorPick.Items.Add("Yellow")
cboColorPick.Items.Add("Purple")
' assigns radiobuttons to array
rbChecked(0) = rbWidth1
rbChecked(1) = rbWidth5
rbChecked(2) = rbWidth10
rbChecked(3) = rbWidth20
End Sub
Private Sub cboColorPick_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles cboColorPick.SelectedIndexChanged
' assigns to index the combobox index of the selected color
index = cboColorPick.SelectedIndex
' calls procedure that assigns color to pen
Call AssignPenColor(index)
End Sub
Private Sub AssignPenColor(ByVal index As Object)
' takes passed index collected from selection in combobox and checks to see which case it matches. once correct one is found
' the userColor variable is assigned the appropriate color
Select Case index
Case 1
userColor = Color.Black
Case 2
userColor = Color.Blue
Case 3
userColor = Color.Pink
Case 4
userColor = Color.Red
Case 5
userColor = Color.Green
Case 6
userColor = Color.Yellow
Case 7
userColor = Color.Purple
End Select
End Sub
' handles checkedchanged event for all radiobuttons
Private Sub rbWidth1_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles rbWidth1.CheckedChanged, _
rbWidth5.CheckedChanged, rbWidth10.CheckedChanged, rbWidth20.CheckedChanged
penWidth = 0
Dim i As Integer = 0
Dim found As Boolean = False
' runs through loop until it finds the radiobutton which was selected within the rbChecked array
While i < rbChecked.GetLength(0) And Not found
If rbChecked(i).Checked Then
found = True
End If
i += 1
End While
' once index is found it is evaluated to determine which width value should be assigned to penWidth variable
Select Case i
Case 0
penWidth = 1
Case 1
penWidth = 5
Case 2
penWidth = 10
Case 3
penWidth = 20
End Select
End Sub
End Class
