For...Next loop nested in another For...Next loop [RESOLVED]

[twisted]

I know exactly what I want to do but don't know how to do it. I want to create a table of 144 rows in ListView control. I have created five columns: multiplicand, X, multiplier, =, and product. This table is going to be a Multiplication table where both the Multiplicand and the Mulitplier vary from 1 through 12, hence 144 rows. I want option strict on and the processing to occur in the form load event only. Anyone got an idea of how to write a Nested For...Next loop for this??

[salvelinus]

What is the processing you want to accomplish? Filling the listview? Calculating the product? Something else?

[twisted]

As soon as the form loads I want the Multiplication Table to display in Listview. I want no user input at all, just a big table with 144 rows like this:

1 X 1 = 1
1 X 2 = 2
1 X 3 = 3
1 X 4 = 4
etc...

the only things I will use for this program is looping and the list view box. Here is my interface if you want to see what I want it to look like. My brother said the best way is to use a For...Next loop nested in another For...Next loop. This is all the code for the program, but I'm illerate when it comes to Nested loops.

Option Strict On
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 ListView1 As System.Windows.Forms.ListView
    Friend WithEvents colMultiplicand As System.Windows.Forms.ColumnHeader
    Friend WithEvents colX As System.Windows.Forms.ColumnHeader
    Friend WithEvents colMultiplier As System.Windows.Forms.ColumnHeader
    Friend WithEvents colEqual As System.Windows.Forms.ColumnHeader
    Friend WithEvents colProduct As System.Windows.Forms.ColumnHeader
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.ListView1 = New System.Windows.Forms.ListView
        Me.colMultiplicand = New System.Windows.Forms.ColumnHeader
        Me.colX = New System.Windows.Forms.ColumnHeader
        Me.colMultiplier = New System.Windows.Forms.ColumnHeader
        Me.colEqual = New System.Windows.Forms.ColumnHeader
        Me.colProduct = New System.Windows.Forms.ColumnHeader
        Me.SuspendLayout()
        '
        'ListView1
        '
        Me.ListView1.Columns.AddRange(New System.Windows.Forms.ColumnHeader() {Me.colMultiplicand, Me.colX, Me.colMultiplier, Me.colEqual, Me.colProduct})
        Me.ListView1.Location = New System.Drawing.Point(0, 0)
        Me.ListView1.Name = "ListView1"
        Me.ListView1.Size = New System.Drawing.Size(304, 344)
        Me.ListView1.TabIndex = 0
        Me.ListView1.View = System.Windows.Forms.View.Details
        '
        'colMultiplicand
        '
        Me.colMultiplicand.Text = "Multiplicand"
        Me.colMultiplicand.Width = 68
        '
        'colX
        '
        Me.colX.Text = "X"
        Me.colX.TextAlign = System.Windows.Forms.HorizontalAlignment.Center
        Me.colX.Width = 19
        '
        'colMultiplier
        '
        Me.colMultiplier.Text = "Multiplier"
        Me.colMultiplier.TextAlign = System.Windows.Forms.HorizontalAlignment.Center
        Me.colMultiplier.Width = 53
        '
        'colEqual
        '
        Me.colEqual.Text = "="
        Me.colEqual.TextAlign = System.Windows.Forms.HorizontalAlignment.Center
        Me.colEqual.Width = 18
        '
        'colProduct
        '
        Me.colProduct.Text = "Product"
        Me.colProduct.TextAlign = System.Windows.Forms.HorizontalAlignment.Center
        Me.colProduct.Width = 79
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(232, 326)
        Me.Controls.Add(Me.ListView1)
        Me.Name = "Form1"
        Me.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen
        Me.Text = "Form1"
        Me.ResumeLayout(False)
 
    End Sub
 
#End Region
 
    Private Sub ListView1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ListView1.SelectedIndexChanged
 
    End Sub
End Class

[dogfish227]

dim num1 as integer
dim num2 as integer
 
 
for num1 = 1 to 12
   for num2 = 1 to 12
      'the first time            num1=1  num2=1
      'secound time           num1=1  num2=2
      '                                num1=1  num2=3
      'it will go lie that till  num1=1  num2=12                 
      ' then                       num1=2  num2=1
                                      num1=2  num2=2
                                      num1=2  num2=3  
                       
   next
next

do you see how they work now? if not i can do a table for all the iterations

for you multiplication table just put the two numbers in the frist and third colum and mutilply them together for your fifth colum

[twisted]

I'm gonna play with this but please do a table for all it will help me a lot. this is just a child form for a big project that I'd rather be done already. Thanks again!

[twisted]

Ok how do I get my num1 to show in (column 1)colMultiplicand and num2 to show in (column 3) colMultiplier, then (column 5)colProduct = num1 * num2

[salvelinus]

Do you know how to add items & subitems to a listview? You might want to look it up, try it, and post some code if you have problems.
Basically, the first column is a listview item, and the other columns are subitems of that. They can be added with .Add, using the counter as an index.
OK, here's an example. You can also add items & subitems at design time. There are other ways to do it.

Dim LvItem as New ListViewItem()   'this would be outside a loop
 
'one way
LvItem.Text = "Blah blah"   
LvItem.SubItems.Add("yada yada")
LvItem.Subitems.Add(strText)
myListView.Items.Add(LvItem)
 
'another way
Set LvItem = myListView.Items.Add("Blah blah")
LvItem.SubItems(1) = "yada yada"
LvItem.SubItems(2) = strText
 
'so
Dim LvItem as New ListViewItem()
For i = 1 to 12
   For j = 1 to 12
      Set LvItem = myListView.Items.Add(i)
      LvItem.SubItems(1) = "x"
      LvItem.SubItems(2) = j
      LvItem.SubItems(3) = "="
      LvItem.SubItems(1) = i * j
   Next
Next

[twisted]

Here is my code with errors under the ones in RED:

Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim LvItem As New ListViewItem
        Dim int1 As Integer
        Dim int2 As Integer
        For int1 = 1 To 12
            For int2 = 1 To 12
                LvItem = lstTable.Items.Add("int1")
                LvItem.SubItems(1) = [COLOR=RED]"X"[/COLOR]
                LvItem.SubItems(2) = [COLOR=RED]int2[/COLOR]
                LvItem.SubItems(3) = [COLOR=RED]("=")[/COLOR]
                LvItem.SubItems(4) = [COLOR=RED](int1 * int2)[/COLOR]
            Next
        Next
 
    End Sub
End Class

Also when I execute the program my Column just fills with int1, not the actual value

[salvelinus]

You have int1 in quotes. It's an integer, not a string.
Anyway, try this. Works for me. The other ways are illustrated in Mastering Visual Basic. Don't forget, you have to add the columns and set the listview to report view first.

For i = 1 To 12
            For j = 1 To 12
                LvItem = myListView.Items.Add(i)
                LvItem.SubItems.Add("x")
                LvItem.SubItems.Add(j)
                LvItem.SubItems.Add("=")
                LvItem.SubItems.Add(i * j)
            Next
        Next

[twisted]

Doesn't work for me?? Don't know why. Also if I don't put int1.ToString it will give me a blue line under it. Everything in RED is giving me a blue line under it??

For int1 = 1 To 12
            For int2 = 1 To 12
                LvItem = lstTable.Items.Add(int1.ToString)
                LvItem.SubItems(1) = [COLOR=RED]"X" [/COLOR]
                LvItem.SubItems(2) = [COLOR=RED]int2[/COLOR]
                LvItem.SubItems(3) = [COLOR=RED]("=")[/COLOR]
                LvItem.SubItems(4) = [COLOR=RED](int1 * int2)[/COLOR]
 
            Next
        Next

[salvelinus]

Notice I'm not using the SubItems(index) method in the last example. Use SubItems.Add()
You might have to cast it if you're using Option Strict, which you normally should. I tested the code real quick w/o it. In that case you'd have to calculate the product (i * j) and cast it to what you want.

Dim LvItem As New ListViewItem()
        Dim i, j, ans As Integer
        For i = 1 To 12
            For j = 1 To 12
                LvItem = myListView.Items.Add(i.ToString)
                LvItem.SubItems.Add("x")
                LvItem.SubItems.Add(j.ToString)
                LvItem.SubItems.Add("=")
                ans = i * j
                LvItem.SubItems.Add(ans.ToString)
            Next
        Next

[twisted]

Overload resolution failed because no accessible 'Add' accepts this number of arguments. Errors in RED!

[COLOR=RED] LvItem.SubItems.Add[/COLOR] = "X" 
[COLOR=RED] LvItem.SubItems.Add[/COLOR] = int2
[COLOR=RED] LvItem.SubItems.Add[/COLOR] = ("=")
[COLOR=RED] LvItem.SubItems.Add[/COLOR]= (int1 * int2)

[robymix]

Originally posted by twisted
Overload resolution failed because no accessible 'Add' accepts this number of arguments. Errors in RED!

[COLOR=RED] LvItem.SubItems.Add[/COLOR] = "X" 
[COLOR=RED] LvItem.SubItems.Add[/COLOR] = int2
[COLOR=RED] LvItem.SubItems.Add[/COLOR] = ("=")
[COLOR=RED] LvItem.SubItems.Add[/COLOR]= (int1 * int2)

This is because you used

LvItem.SubItems.Add = "X"

instead of

LvItem.SubItems.Add("X")

'Add' is a method which accepts arguments and cannot be the target of an assignment.

[salvelinus]

Look at the example. You're not doing it correctly.

[twisted]

Is this better b/c the errors are still in the same places??

Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim LvItem As New ListViewItem
        Dim int1, int2, ans As Integer
 
        For int1 = 1 To 12
            For int2 = 1 To 12
                LvItem = lstTable.Items.Add(int1.ToString)
                [COLOR=RED]LvItem.SubItems.Add[/COLOR] = ("X")
                [COLOR=RED]LvItem.SubItems.Add[/COLOR] = (int2.ToString)
                [COLOR=RED]LvItem.SubItems.Add[/COLOR] = ("=")
                ans = int1 * int2
                [COLOR=RED]LvItem.SubItems.Add[/COLOR] = (ans.ToString)
 
            Next
        Next
 
    End Sub

[twisted]

The first column is turning out great and looping perfectly. Just can't get the other subitems to add.

Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim LvItem As New ListViewItem
        Dim int1, int2, ans As Integer
 
        For int1 = 1 To 12
            For int2 = 1 To 12
' Works Perfect
                LvItem = lstTable.Items.Add(int1.ToString)
' Doesn't Add
                LvItem.SubItems.Add = ("X")
' Doesn't Add
                LvItem.SubItems.Add = (int2.ToString)
' Doesn't Add
                LvItem.SubItems.Add = ("=")
' Works Perfect
                ans = int1 * int2
' Doesn't Add
                LvItem.SubItems.Add = (ans.ToString)
            Next
        Next
 
    End Sub

[salvelinus]

LvItem.SubItems.Add = ("X")  'WRONG!
 
LvItem.SubItems.Add("X")   'RIGHT!

[twisted]

HAHA! I don't listen very well do I? You said that above and I kept looking over it. Thanks man, it works perfect!