We value your feedback.
Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!
Course Of The Month
4 days, left to enrollBecome a Premium Member and unlock a new, free course in leading technologies each month.
Solved
An arrayList of arrayLists VB.NET
Posted on 2004-09-01
I have an arrayList in which I put objects (objects containing some connected lines and a pen)
then I draw all the objects from the arrayList.
Now, I want to make an arraylist of arrayLists (every curve with 400 connected lines is in an arrayList)
This way I would be able to draw any specific curve I wish, instead of drawing them all.
Notice that both the ArrayList and the collection of arrayLists need to be dynamic(so I can add to it)
Any idea?
Here is my idea:
Public Curves As ArrayList
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim ACurveObject As New ArrayList
ACurveObject.Add(New LineObject(New Point(x1, y1), New Point(x2, y2)))
Curves.Add(ACurveObject)
End Sub
then I draw all the objects from the arrayList.
Now, I want to make an arraylist of arrayLists (every curve with 400 connected lines is in an arrayList)
This way I would be able to draw any specific curve I wish, instead of drawing them all.
Notice that both the ArrayList and the collection of arrayLists need to be dynamic(so I can add to it)
Any idea?
Here is my idea:
Public Curves As ArrayList
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim ACurveObject As New ArrayList
ACurveObject.Add(New LineObject(New Point(x1, y1), New Point(x2, y2)))
Curves.Add(ACurveObject)
End Sub
[X]
Welcome to Experts Exchange
Add your voice to the tech community where 5M+ people just like you are talking about what matters.
- Help others & share knowledge
- Earn cash & points
- Learn & ask questions
-
6
3
9 Comments
Active today
There is nothing wrong with having an ArrayList of ArrayLists but...
From an OOP perspective though, I think it would make more sense to create a Class called "Curve" to encapsulate an ArrayList containing your 400 LineObjects. You could add an ID or CurveName property to the class to give each instance a unique identifier.
Then I would use a HashTable to store all the instances of your Curve class. You can use the unique identifier of each Curve instance as the key value for adding into the HashTable. This way you can easily retrieve any specific curve you need without looping through an ArrayList.
My free two cents,
Idle_Mind
From an OOP perspective though, I think it would make more sense to create a Class called "Curve" to encapsulate an ArrayList containing your 400 LineObjects. You could add an ID or CurveName property to the class to give each instance a unique identifier.
Then I would use a HashTable to store all the instances of your Curve class. You can use the unique identifier of each Curve instance as the key value for adding into the HashTable. This way you can easily retrieve any specific curve you need without looping through an ArrayList.
My free two cents,
Idle_Mind
Enev though it is not essencial, I simply want to categorize the ArrayList. I'm not sure about the key parameter of HashTable. I hope a HashTable can hold ArrayLists.
I like the idea of making a class called "Curve" obvously you do not mean having a class in the module (because when making a new forms, they all refer to the same curves)
I made the class, but I've never made a property that would return an arrayList with a key??. All I tried failed since I don't know about the key or what you call ID.
You are more than welcome to comment.
I increased the points...if you think this question is still worth more, let me know.
Regard, Kourosh
I like the idea of making a class called "Curve" obvously you do not mean having a class in the module (because when making a new forms, they all refer to the same curves)
I made the class, but I've never made a property that would return an arrayList with a key??. All I tried failed since I don't know about the key or what you call ID.
You are more than welcome to comment.
I increased the points...if you think this question is still worth more, let me know.
Regard, Kourosh
Idle_Mind:"There is nothing wrong with having an ArrayList of ArrayLists"
Well, technically I am not sure, since an ArrayList is a collection type but you can add objects to an ArrayList.
I think I am very close to solving this. I have a class with a Read-Only property.
Would you copy paste and see the single problem:
'===Module:
Module Module1
Public Interface GraphObject
Sub Paint(ByRef g As Graphics)
End Interface
Public Class LineObject
Implements GraphObject
Private pointA As Point
Private pointB As Point
Public Sub New(ByVal ptA As Point, ByVal ptB As Point)
pointA = ptA
pointB = ptB
End Sub
Public Sub Paint(ByRef g As Graphics) Implements GraphObject.Paint
g.DrawLine(Pens.Black, pointA, pointB)
End Sub
End Class
End Module
'=======Form1:
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.ICon
'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 Button1 As System.Windows.Forms.Butto
Friend WithEvents PictureBox1 As System.Windows.Forms.Pictu
Friend WithEvents CheckedListBox1 As System.Windows.Forms.Check
<System.Diagnostics.Debugg
Me.Button1 = New System.Windows.Forms.Butto
Me.PictureBox1 = New System.Windows.Forms.Pictu
Me.CheckedListBox1 = New System.Windows.Forms.Check
Me.SuspendLayout()
'
'Button1
'
Me.Button1.Location = New System.Drawing.Point(16, 304)
Me.Button1.Name = "Button1"
Me.Button1.Size = New System.Drawing.Size(120, 72)
Me.Button1.TabIndex = 0
Me.Button1.Text = "Make a new collection of lines collection containing 100 objects in each"
'
'PictureBox1
'
Me.PictureBox1.Anchor = CType((((System.Windows.Fo
Or System.Windows.Forms.Ancho
Or System.Windows.Forms.Ancho
Me.PictureBox1.BackColor = System.Drawing.Color.White
Me.PictureBox1.BorderStyle
Me.PictureBox1.Location = New System.Drawing.Point(24, 16)
Me.PictureBox1.Name = "PictureBox1"
Me.PictureBox1.Size = New System.Drawing.Size(528, 272)
Me.PictureBox1.TabIndex = 1
Me.PictureBox1.TabStop = False
'
'CheckedListBox1
'
Me.CheckedListBox1.BorderS
Me.CheckedListBox1.CheckOn
Me.CheckedListBox1.Locatio
Me.CheckedListBox1.Name = "CheckedListBox1"
Me.CheckedListBox1.Size = New System.Drawing.Size(400, 92)
Me.CheckedListBox1.TabInde
'
'Form1
'
Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
Me.ClientSize = New System.Drawing.Size(560, 414)
Me.Controls.Add(Me.Checked
Me.Controls.Add(Me.Picture
Me.Controls.Add(Me.Button1
Me.Name = "Form1"
Me.Text = "Form1"
Me.ResumeLayout(False)
End Sub
#End Region
Private Curves As ClassCurves
Private rnd As New Random(DateTime.Now().Seco
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim ACurveObject As New ArrayList
Dim x1, y1, x2, y2 As Integer
For num As Short = 1 To 100
x1 = rnd.NextDouble() * PictureBox1.Width
y1 = rnd.NextDouble() * PictureBox1.Height
x2 = rnd.NextDouble() * PictureBox1.Width
y2 = rnd.NextDouble() * PictureBox1.Height
Dim ln As New LineObject(New Point(x1, y1), New Point(x2, y2))
ACurveObject.Add(ln)
Next num
Curves.CollectionOfCurves.
CheckedListBox1.Items.Add(
PictureBox1.Refresh()
End Sub
Private Sub PictureBox1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.Paint
Dim go As Object
Dim SelectedCurvesArray(Checke
Dim indArr = 0
For num As Short = 0 To CheckedListBox1.Items.Coun
If CheckedListBox1.Items.Item
SelectedCurvesArray(indArr
indArr += 1
End If
Next
Dim ind As Short
For Each ind In SelectedCurvesArray
For Each go In Curves.CollectionOfCurves.
go.paint(e.Graphics)
Next
Next
End Sub
End Class
'=======ClassCurves:
Public Class ClassCurves
Private CurvesCollection As ArrayList
Public ReadOnly Property CollectionOfCurves() As ArrayList
Get
Return CurvesCollection
End Get
End Property
End Class
Well, technically I am not sure, since an ArrayList is a collection type but you can add objects to an ArrayList.
I think I am very close to solving this. I have a class with a Read-Only property.
Would you copy paste and see the single problem:
'===Module:
Module Module1
Public Interface GraphObject
Sub Paint(ByRef g As Graphics)
End Interface
Public Class LineObject
Implements GraphObject
Private pointA As Point
Private pointB As Point
Public Sub New(ByVal ptA As Point, ByVal ptB As Point)
pointA = ptA
pointB = ptB
End Sub
Public Sub Paint(ByRef g As Graphics) Implements GraphObject.Paint
g.DrawLine(Pens.Black, pointA, pointB)
End Sub
End Class
End Module
'=======Form1:
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.ICon
'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 Button1 As System.Windows.Forms.Butto
Friend WithEvents PictureBox1 As System.Windows.Forms.Pictu
Friend WithEvents CheckedListBox1 As System.Windows.Forms.Check
<System.Diagnostics.Debugg
Me.Button1 = New System.Windows.Forms.Butto
Me.PictureBox1 = New System.Windows.Forms.Pictu
Me.CheckedListBox1 = New System.Windows.Forms.Check
Me.SuspendLayout()
'
'Button1
'
Me.Button1.Location = New System.Drawing.Point(16, 304)
Me.Button1.Name = "Button1"
Me.Button1.Size = New System.Drawing.Size(120, 72)
Me.Button1.TabIndex = 0
Me.Button1.Text = "Make a new collection of lines collection containing 100 objects in each"
'
'PictureBox1
'
Me.PictureBox1.Anchor = CType((((System.Windows.Fo
Or System.Windows.Forms.Ancho
Or System.Windows.Forms.Ancho
Me.PictureBox1.BackColor = System.Drawing.Color.White
Me.PictureBox1.BorderStyle
Me.PictureBox1.Location = New System.Drawing.Point(24, 16)
Me.PictureBox1.Name = "PictureBox1"
Me.PictureBox1.Size = New System.Drawing.Size(528, 272)
Me.PictureBox1.TabIndex = 1
Me.PictureBox1.TabStop = False
'
'CheckedListBox1
'
Me.CheckedListBox1.BorderS
Me.CheckedListBox1.CheckOn
Me.CheckedListBox1.Locatio
Me.CheckedListBox1.Name = "CheckedListBox1"
Me.CheckedListBox1.Size = New System.Drawing.Size(400, 92)
Me.CheckedListBox1.TabInde
'
'Form1
'
Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
Me.ClientSize = New System.Drawing.Size(560, 414)
Me.Controls.Add(Me.Checked
Me.Controls.Add(Me.Picture
Me.Controls.Add(Me.Button1
Me.Name = "Form1"
Me.Text = "Form1"
Me.ResumeLayout(False)
End Sub
#End Region
Private Curves As ClassCurves
Private rnd As New Random(DateTime.Now().Seco
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim ACurveObject As New ArrayList
Dim x1, y1, x2, y2 As Integer
For num As Short = 1 To 100
x1 = rnd.NextDouble() * PictureBox1.Width
y1 = rnd.NextDouble() * PictureBox1.Height
x2 = rnd.NextDouble() * PictureBox1.Width
y2 = rnd.NextDouble() * PictureBox1.Height
Dim ln As New LineObject(New Point(x1, y1), New Point(x2, y2))
ACurveObject.Add(ln)
Next num
Curves.CollectionOfCurves.
CheckedListBox1.Items.Add(
PictureBox1.Refresh()
End Sub
Private Sub PictureBox1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.Paint
Dim go As Object
Dim SelectedCurvesArray(Checke
Dim indArr = 0
For num As Short = 0 To CheckedListBox1.Items.Coun
If CheckedListBox1.Items.Item
SelectedCurvesArray(indArr
indArr += 1
End If
Next
Dim ind As Short
For Each ind In SelectedCurvesArray
For Each go In Curves.CollectionOfCurves.
go.paint(e.Graphics)
Next
Next
End Sub
End Class
'=======ClassCurves:
Public Class ClassCurves
Private CurvesCollection As ArrayList
Public ReadOnly Property CollectionOfCurves() As ArrayList
Get
Return CurvesCollection
End Get
End Property
End Class
Active today
Try this out...
Regards,
{pseudocode} / {Time} ± ¼*ƒ(Me.Thoughts÷3)^² = Idle »(°_°)« Mind
' --------------------------
' Module1
' --------------------------
Module Module1
Public Interface GraphObject
Sub Paint(ByRef g As Graphics)
End Interface
Public Class LineObject
Implements GraphObject
Private pointA As Point
Private pointB As Point
Public Sub New(ByVal ptA As Point, ByVal ptB As Point)
pointA = ptA
pointB = ptB
End Sub
Public Sub Paint(ByRef g As Graphics) Implements GraphObject.Paint
g.DrawLine(Pens.Black, pointA, pointB)
End Sub
End Class
Public Class ClassCurves
Implements GraphObject
Public ID As String
Public CurvesCollection As ArrayList = New ArrayList
Public Overrides Function toString() As String
Return "Curve #" & ID
End Function
Public Sub Paint(ByRef g As System.Drawing.Graphics) Implements GraphObject.Paint
Dim lo As LineObject
For Each lo In CurvesCollection
lo.Paint(g)
Next
End Sub
End Class
End Module
' --------------------------
' Form1
' --------------------------
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.ICon
'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 Button1 As System.Windows.Forms.Butto
Friend WithEvents PictureBox1 As System.Windows.Forms.Pictu
Friend WithEvents CheckedListBox1 As System.Windows.Forms.Check
<System.Diagnostics.Debugg
Me.Button1 = New System.Windows.Forms.Butto
Me.PictureBox1 = New System.Windows.Forms.Pictu
Me.CheckedListBox1 = New System.Windows.Forms.Check
Me.SuspendLayout()
'
'Button1
'
Me.Button1.Anchor = CType((System.Windows.Form
Me.Button1.Location = New System.Drawing.Point(16, 272)
Me.Button1.Name = "Button1"
Me.Button1.Size = New System.Drawing.Size(120, 72)
Me.Button1.TabIndex = 0
Me.Button1.Text = "Make a new collection of lines collection containing 100 objects in each"
'
'PictureBox1
'
Me.PictureBox1.Anchor = CType((((System.Windows.Fo
Or System.Windows.Forms.Ancho
Or System.Windows.Forms.Ancho
Me.PictureBox1.BackColor = System.Drawing.Color.White
Me.PictureBox1.BorderStyle
Me.PictureBox1.Location = New System.Drawing.Point(24, 16)
Me.PictureBox1.Name = "PictureBox1"
Me.PictureBox1.Size = New System.Drawing.Size(552, 240)
Me.PictureBox1.TabIndex = 1
Me.PictureBox1.TabStop = False
'
'CheckedListBox1
'
Me.CheckedListBox1.Anchor = CType(((System.Windows.For
Or System.Windows.Forms.Ancho
Me.CheckedListBox1.BorderS
Me.CheckedListBox1.CheckOn
Me.CheckedListBox1.Locatio
Me.CheckedListBox1.Name = "CheckedListBox1"
Me.CheckedListBox1.Size = New System.Drawing.Size(424, 92)
Me.CheckedListBox1.TabInde
'
'Form1
'
Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
Me.ClientSize = New System.Drawing.Size(584, 382)
Me.Controls.Add(Me.Checked
Me.Controls.Add(Me.Picture
Me.Controls.Add(Me.Button1
Me.Name = "Form1"
Me.Text = "Form1"
Me.ResumeLayout(False)
End Sub
#End Region
Private rnd As New Random(DateTime.Now().Seco
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim curve As ClassCurves = New ClassCurves
curve.ID = CheckedListBox1.Items.Coun
Dim x1, y1, x2, y2 As Integer
For num As Short = 1 To 100
x1 = rnd.NextDouble() * PictureBox1.Width
y1 = rnd.NextDouble() * PictureBox1.Height
x2 = rnd.NextDouble() * PictureBox1.Width
y2 = rnd.NextDouble() * PictureBox1.Height
curve.CurvesCollection.Add
Next num
CheckedListBox1.Items.Add(
PictureBox1.Refresh()
End Sub
Private Sub CheckedListBox1_SelectedIn
PictureBox1.Refresh()
End Sub
Private Sub PictureBox1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.Paint
Dim go As GraphObject
e.Graphics.Clear(PictureBo
For Each go In CheckedListBox1.CheckedIte
go.Paint(e.Graphics)
Next
End Sub
End Class
Regards,
{pseudocode} / {Time} ± ¼*ƒ(Me.Thoughts÷3)^² = Idle »(°_°)« Mind
' --------------------------
' Module1
' --------------------------
Module Module1
Public Interface GraphObject
Sub Paint(ByRef g As Graphics)
End Interface
Public Class LineObject
Implements GraphObject
Private pointA As Point
Private pointB As Point
Public Sub New(ByVal ptA As Point, ByVal ptB As Point)
pointA = ptA
pointB = ptB
End Sub
Public Sub Paint(ByRef g As Graphics) Implements GraphObject.Paint
g.DrawLine(Pens.Black, pointA, pointB)
End Sub
End Class
Public Class ClassCurves
Implements GraphObject
Public ID As String
Public CurvesCollection As ArrayList = New ArrayList
Public Overrides Function toString() As String
Return "Curve #" & ID
End Function
Public Sub Paint(ByRef g As System.Drawing.Graphics) Implements GraphObject.Paint
Dim lo As LineObject
For Each lo In CurvesCollection
lo.Paint(g)
Next
End Sub
End Class
End Module
' --------------------------
' Form1
' --------------------------
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.ICon
'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 Button1 As System.Windows.Forms.Butto
Friend WithEvents PictureBox1 As System.Windows.Forms.Pictu
Friend WithEvents CheckedListBox1 As System.Windows.Forms.Check
<System.Diagnostics.Debugg
Me.Button1 = New System.Windows.Forms.Butto
Me.PictureBox1 = New System.Windows.Forms.Pictu
Me.CheckedListBox1 = New System.Windows.Forms.Check
Me.SuspendLayout()
'
'Button1
'
Me.Button1.Anchor = CType((System.Windows.Form
Me.Button1.Location = New System.Drawing.Point(16, 272)
Me.Button1.Name = "Button1"
Me.Button1.Size = New System.Drawing.Size(120, 72)
Me.Button1.TabIndex = 0
Me.Button1.Text = "Make a new collection of lines collection containing 100 objects in each"
'
'PictureBox1
'
Me.PictureBox1.Anchor = CType((((System.Windows.Fo
Or System.Windows.Forms.Ancho
Or System.Windows.Forms.Ancho
Me.PictureBox1.BackColor = System.Drawing.Color.White
Me.PictureBox1.BorderStyle
Me.PictureBox1.Location = New System.Drawing.Point(24, 16)
Me.PictureBox1.Name = "PictureBox1"
Me.PictureBox1.Size = New System.Drawing.Size(552, 240)
Me.PictureBox1.TabIndex = 1
Me.PictureBox1.TabStop = False
'
'CheckedListBox1
'
Me.CheckedListBox1.Anchor = CType(((System.Windows.For
Or System.Windows.Forms.Ancho
Me.CheckedListBox1.BorderS
Me.CheckedListBox1.CheckOn
Me.CheckedListBox1.Locatio
Me.CheckedListBox1.Name = "CheckedListBox1"
Me.CheckedListBox1.Size = New System.Drawing.Size(424, 92)
Me.CheckedListBox1.TabInde
'
'Form1
'
Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
Me.ClientSize = New System.Drawing.Size(584, 382)
Me.Controls.Add(Me.Checked
Me.Controls.Add(Me.Picture
Me.Controls.Add(Me.Button1
Me.Name = "Form1"
Me.Text = "Form1"
Me.ResumeLayout(False)
End Sub
#End Region
Private rnd As New Random(DateTime.Now().Seco
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim curve As ClassCurves = New ClassCurves
curve.ID = CheckedListBox1.Items.Coun
Dim x1, y1, x2, y2 As Integer
For num As Short = 1 To 100
x1 = rnd.NextDouble() * PictureBox1.Width
y1 = rnd.NextDouble() * PictureBox1.Height
x2 = rnd.NextDouble() * PictureBox1.Width
y2 = rnd.NextDouble() * PictureBox1.Height
curve.CurvesCollection.Add
Next num
CheckedListBox1.Items.Add(
PictureBox1.Refresh()
End Sub
Private Sub CheckedListBox1_SelectedIn
PictureBox1.Refresh()
End Sub
Private Sub PictureBox1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.Paint
Dim go As GraphObject
e.Graphics.Clear(PictureBo
For Each go In CheckedListBox1.CheckedIte
go.Paint(e.Graphics)
Next
End Sub
End Class
Excellent.
I thought that if I use a class in the module _like you did_ when I have different instances (copies) of the form, they would all refer to one collection (meaning that several applications would display the same curves)...But that is not true, which is gooooooooood.
I still do not know what went wrong with my previous code...?
Thanks a lot.
^ ^
+ +
[ | ]
\==/
Regards.
I thought that if I use a class in the module _like you did_ when I have different instances (copies) of the form, they would all refer to one collection (meaning that several applications would display the same curves)...But that is not true, which is gooooooooood.
I still do not know what went wrong with my previous code...?
Thanks a lot.
^ ^
+ +
[ | ]
\==/
Regards.
Oops. I noticed the collection will be erased? If you put the following in a button_Sub click and click the button after drawing, it displays 0.
Dim curves As New ClassCurves
MsgBox(CStr(curves.CurvesC
I think that your code actually stores the arrayList in the CheckedListBox. Is that so???
So there is only one temporary collection !
Since I'm using a different form for CheckedListBox, I lose the collection because I hide the form that contians the checkedListBox; so, it is erased when it is hidden.
Would you explain why the objects of a CheckedListBox are erased when it is hidden ?
Dim curves As New ClassCurves
MsgBox(CStr(curves.CurvesC
I think that your code actually stores the arrayList in the CheckedListBox. Is that so???
So there is only one temporary collection !
Since I'm using a different form for CheckedListBox, I lose the collection because I hide the form that contians the checkedListBox; so, it is erased when it is hidden.
Would you explain why the objects of a CheckedListBox are erased when it is hidden ?
Active today
You can keep your ClassCurves instances in a Hashtable instead of the CheckedListBox as shown below. Then you can pass a reference to the HashTable to other forms so you can build the CheckedListBox based on the key values.
Idle_Mind
Public Class Form1
Inherits System.Windows.Forms.Form
' #Region " Windows Form Designer generated code "
Private rnd As New Random(DateTime.Now().Seco
Private curves As New Hashtable
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim curve As ClassCurves = New ClassCurves
curve.ID = CheckedListBox1.Items.Coun
Dim x1, y1, x2, y2 As Integer
For num As Short = 1 To 100
x1 = rnd.NextDouble() * PictureBox1.Width
y1 = rnd.NextDouble() * PictureBox1.Height
x2 = rnd.NextDouble() * PictureBox1.Width
y2 = rnd.NextDouble() * PictureBox1.Height
curve.CurvesCollection.Add
Next num
curves.Add(curve.ToString,
CheckedListBox1.Items.Add(
PictureBox1.Refresh()
End Sub
Private Sub CheckedListBox1_SelectedIn
PictureBox1.Refresh()
End Sub
Private Sub PictureBox1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.Paint
Dim curveName As String
Dim go As GraphObject
e.Graphics.Clear(PictureBo
For Each curveName In CheckedListBox1.CheckedIte
go = curves.Item(curveName)
go.Paint(e.Graphics)
Next
End Sub
End Class
Idle_Mind
Public Class Form1
Inherits System.Windows.Forms.Form
' #Region " Windows Form Designer generated code "
Private rnd As New Random(DateTime.Now().Seco
Private curves As New Hashtable
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim curve As ClassCurves = New ClassCurves
curve.ID = CheckedListBox1.Items.Coun
Dim x1, y1, x2, y2 As Integer
For num As Short = 1 To 100
x1 = rnd.NextDouble() * PictureBox1.Width
y1 = rnd.NextDouble() * PictureBox1.Height
x2 = rnd.NextDouble() * PictureBox1.Width
y2 = rnd.NextDouble() * PictureBox1.Height
curve.CurvesCollection.Add
Next num
curves.Add(curve.ToString,
CheckedListBox1.Items.Add(
PictureBox1.Refresh()
End Sub
Private Sub CheckedListBox1_SelectedIn
PictureBox1.Refresh()
End Sub
Private Sub PictureBox1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.Paint
Dim curveName As String
Dim go As GraphObject
e.Graphics.Clear(PictureBo
For Each curveName In CheckedListBox1.CheckedIte
go = curves.Item(curveName)
go.Paint(e.Graphics)
Next
End Sub
End Class
Hello Idle_Mind.
Thanks a lot.
With your example, I understood the usage of Hushtables and writing Overridable methods. That is a perfect usage...
Regards, kourosh
Thanks a lot.
With your example, I understood the usage of Hushtables and writing Overridable methods. That is a perfect usage...
Regards, kourosh
Hi Idle-Mind. Again the listBox was erased, but I found the real bug. I used to "Hide" the form containing the checkedListBox. That is the bug !!!!
I fixed the bug by changing "form1.hide" to "form1.visible=False"
I'd read a book about vb.Net it said "hide and visible=False are essentailly the same"
but that's not true !
In any case, your HashTable idea is valuable to me !
Have fun.
Regards, Kourosh.
**** **** * I'm not as "think" as you "drunk" I am !
* **** ****
I fixed the bug by changing "form1.hide" to "form1.visible=False"
I'd read a book about vb.Net it said "hide and visible=False are essentailly the same"
but that's not true !
In any case, your HashTable idea is valuable to me !
Have fun.
Regards, Kourosh.
**** **** * I'm not as "think" as you "drunk" I am !
* **** ****
Featured Post
On-screen guidance at the moment of need enables you & your employees to focus on the core, you can now boost your adoption rates swiftly and simply with one easy tool.
Question has a verified solution.
If you are experiencing a similar issue, please ask a related question
If you're writing a .NET application to connect to an Access .mdb database and use pre-existing queries that require parameters, you've come to the right place!
Let's say the pre-existing query(qryCust) in Access takes a Date as a parameter and l…
Calculating holidays and working days is a function that is often needed yet it is not one found within the Framework. This article presents one approach to building a working-day calculator for use in .NET.
This is a high-level webinar that covers the history of enterprise open source database use. It addresses both the advantages companies see in using open source database technologies, as well as the fears and reservations they might have.
In this…
This is my first video review of Microsoft Bookings, I will be doing a part two with a bit more information, but wanted to get this out to you folks.
Suggested Courses
Course of the Month4 days, left to enroll
691 members asked questions and received personalized solutions in the past 7 days.
Join the community of 500,000 technology professionals and ask your questions.