Generate 1 Letter in all Labels - vb.net

Good Morning
I am creating an application that has 100 Labels from Label1 to Label100. My Target here is that all of that Labels must generate random letters in the alphabet no matter if it is repeated as long as its different.
Here is my code I tried.
Dim validchars As String = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
Dim sb As New StringBuilder()
Dim rand As New Random()
For i As Integer = 1 To 1
Dim idx As Integer = rand.Next(0, validchars.Length)
Dim randomChar As Char = validchars(idx)
sb.Append(randomChar)
Next i
Label1.Text = sb.ToString()
Label2.Text = sb.ToString()
Label3.Text = sb.ToString()
Label4.Text = sb.ToString()
Label5.Text = sb.ToString()
Label6.Text = sb.ToString()
Label7.Text = sb.ToString()
Label8.Text = sb.ToString()
'and so on until i reached Label100
But my output is this :(
Please ignore the other letters because i tried to code until Label50
How can i achieve it? and is there other way to shorten up calling each label?
TYSM for future help

Is this what you're going for (c#)? Basically, creating the Labels on the fly, and adding them to a FlowLayoutPanel for stacking and positioning.
var alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
Random random = new Random();
for (int i = 0; i < 100; i++)
{
Label label = new Label();
label.Text = alphabet[random.Next(0, alphabet.Length)].ToString();
flowLayoutPanel1.Controls.Add(label);
}
VB.NET:
Dim alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
Dim random As New Random()
For i As Integer = 0 To 99
Dim label As New Label()
label.Text = alphabet(random.[Next](0, alphabet.Length)).ToString()
flowLayoutPanel1.Controls.Add(label)
Next

Option 1, with your existing form:
I would have created the labels in the code and not in the designer, but if you already have them, you can do this:
private void Form1_Load(object sender, EventArgs e)
{
var labels = this.Controls.OfType<Label>();
var rnd = new Random();
foreach (var label in labels)
{
label.Text = ((char)(rnd.Next(26) + 'A')).ToString();
}
}
Simply loop through all the form's labels (you may filter them if necessary) and assign each one a random letter. And that's all. No need to use StringBuilders or an array with the letters.
I also used Convertor to turn it into VB, I hope it works:
Private Sub Form1_Load(sender As Object, e As EventArgs)
Dim labels = Me.Controls.OfType(Of Label)()
Dim rnd = New Random()
For Each label As var In labels
label.Text = CChar(rnd.[Next](26) + "A"C).ToString()
Next
End Sub
Option 2, starting from scratch:
Finally, based on mariocatch's answer, which uses a FlowLayoutPanel, I suggest you do this:
Start with an empty form.
Add a Panel.
Set its Dock property to Bottom.
Add a Button inside.
Go to its Anchor property and deselect Top and Left (nothing selected).
Set the panel's height and center the button horizontally.
Add a FlowLayoutPanel in the middle of the form.
Set its Dock property to Fill.
And nothing else there. Then use this code:
Private Sub Form1_Load(sender As Object, e As EventArgs)
Dim rnd = New Random()
For i As Integer = 0 To 49
Dim label = New Label()
label.Width = 20
label.Text = CChar(rnd.[Next](26) + "A"C).ToString()
Me.flowLayoutPanel1.Controls.Add(label)
Next
End Sub
After this I think you can adjust all the details without any issue.

Here is the VB.NET version of the code provided by #mariocatch. I like it.
Dim alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
Dim random As New Random()
For i As Integer = 0 To 99
Dim label As New Label()
label.Text = alphabet(random.Next(0, alphabet.Length)).ToString()
flowLayoutPanel1.Controls.Add(label)
Next
This is the Convertor used online for converting C# code to VB.NET code for reference.

Assuming labels up to 50 are the ones with the "F"s:
You've determined the value of sb once you left the loop. You're then taking that value and setting that to the text of each label, which is why it wouldn't work. You've also created a loop starting at 1 and ending at 1, which is a pretty pointless loop as it only runs once. If you modify the loop to generate 100 characters in the stringbuilder and then set the nth label to the nth character of the stringbuilder, this should work.

Related

How to dynamicallty create multiple controls at runtime

I am trying to add multiple labels to a userform at runtime
It's for the player names of a board game; and until the game starts the number of players are not known. I have managed to figure out for myself how to use the dynamic array function to create the list of players. I used a For.....Next loop to add the player names. I thought I could do that to add the labels to the form, but it only adds one. Depending on where the new control type is declared, it either adds the first player only, or the last player
This code produces one label only within the groupbox, the last player
Public Class Form1
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim Players_Num As Integer = InputBox("Enter the number of players")
Dim Players(Players_Num) As String
Dim newText As New Label
For i = 0 To Players_Num - 1
Players(i) = InputBox("Enter player name")
Next
'This piece of code was jsut for me to test that I was successfully using a For...Loop
'to add the players names, and will be deleted later on
For x = 0 To Players_Num - 1
MessageBox.Show(Players(x))
Next
For z = 0 To Players_Num - 1
newText.Name = "txt" & Players(z)
newText.Text = Players(z)
newText.Size = New Size(170, 20)
newText.Location = New Point(12 + 5, 12 + 5)
GroupBox1.Controls.Add(newText)
Next
End Sub
End Class
This one places only the first player
Public Class Form1
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim Players_Num As Integer = InputBox("Enter the number of players")
Dim Players(Players_Num) As String
For i = 0 To Players_Num - 1
Players(i) = InputBox("Enter player name")
Next
'This piece of code was jsut for me to test that I was successfully using a For...Loop
'to add the players names, and will be deleted later on
For x = 0 To Players_Num - 1
MessageBox.Show(Players(x))
Next
For z = 0 To Players_Num - 1
Dim newText As New Label
newText.Name = "txt" & Players(z)
newText.Text = Players(z)
newText.Size = New Size(170, 20)
newText.Location = New Point(12 + 5, 12 + 5)
GroupBox1.Controls.Add(newText)
Next
End Sub
End Class
I've tried this in vs 2015 and 2019 Community
Where is it going wrong?
From the looks of the code, you are correctly creating the controls but their location is the same for all of them, essentially, they are being place one of top of the other, the first is hidden with the second, which is hidden with the third.
The line
newText.Location = New Point(12 + 5, 12 + 5)
needs to be modified to place the labels at different locations.
Perhaps, something like:
newText.Location = New Point(12 + 5, 12 + (z * 25))
This will vertically align the labels with a gap of 25 between them
You are placing them all in the same location
newText.Location = New Point(12 + 5, 12 + 5)
Use your 'z' index to place them at different locations in order to be able to see them
For me it is easier to contain controls in a TableLayoutPanel then add the TLP to what ever control collection, such as a GroupBox This way you can couple a Label with TextBox, for example. Here's an example how you can create controls from a DataTable. In your case you would only need 1 ColumnStyle for labels, I just thought I would show you a good practice for future shortcuts. (I rarely use the designer to place controls)
'Start test data
Dim DtTable As New DataTable
With DtTable
Dim NewDtRow As DataRow = .NewRow
For i As Integer = 0 To 25
Dim DtCol As New DataColumn With {.ColumnName = "Col" & i, .DataType = GetType(String)}
.Columns.Add(DtCol)
NewDtRow(DtCol.ColumnName) = "Test" & i
Next
.Rows.Add(NewDtRow)
End With
'End test data
Dim TLP1 As New TableLayoutPanel With {.Name = "TlpFields"}
With TLP1
.BorderStyle = BorderStyle.Fixed3D
.CellBorderStyle = TableLayoutPanelCellBorderStyle.Inset
.AutoScroll = True
.AutoSize = True
.RowStyles.Clear()
.ColumnStyles.Clear()
.Dock = DockStyle.Fill
.ColumnCount = 2
.ColumnStyles.Add(New ColumnStyle With {.SizeType = SizeType.AutoSize})
End With
For Each DtCol As DataColumn In DtTable.Columns
With TLP1
.RowCount += 1
.RowStyles.Add(New RowStyle With {.SizeType = SizeType.AutoSize})
'create labels
.Controls.Add(New Label With {
.Text = DtCol.ColumnName,
.Anchor = AnchorStyles.Right}, 0, .RowCount)
'create textboxs
Dim TxtBox As New TextBox With {
.Name = "TextBox" & DtCol.ColumnName,
.Size = New Size(170, 20),
.Anchor = AnchorStyles.Left}
'add binding
TxtBox.DataBindings.Add("Text", DtTable, DtCol.ColumnName)
.Controls.Add(TxtBox, 1, .RowCount)
End With
Next
Controls.Add(TLP1)

Read data from dynamically created text-box

I'm trying to collect data after creating dynamic text-box with vb.net
Private Sub btn_OK_lines_number_Click(sender As Object, e As EventArgs)
Handles btn_OK_lines_number.Click
Dim i As Integer
Dim x As Integer
Dim Z As Integer
Z = 150
If IsNumeric(txt_lines_number.Text) Then
Int32.TryParse(txt_lines_number.Text, x)
For i = 1 To x
Dim newTB As New TextBox
Dim newLB As New Label
newLB.Name = "lbl_workstation_number_line" & i
newLB.Text = "Nbr Work Station in Line" & i
newLB.Size = New Size(190, 20)
newLB.ForeColor = Color.White
newLB.Font = New Font("consolas", 12, FontStyle.Regular, GraphicsUnit.Pixel)
newLB.Location = New Point(20, Z + i * 30)
newTB.Name = "Textbox" & i
newTB.Size = New Size(170, 20)
newTB.Location = New Point(200, Z + i * 30)
Me.Controls.Add(newTB)
Me.Controls.Add(newLB)
Next
i = i + 1
Else
MessageBox.Show("please enter a number")
txt_lines_number.Text = ""
End If
End Sub
Let's say you just have one row, and only create one TextBox. You set the name here:
newTB.Name = "Textbox" & i
where the resulting TextBox is named Textbox1. The problem is you can't just reference the identifier Textbox1 directly in your code, as you do with txt_lines_number. You can't even reference it as a member of the class (Me.Textbox1). This name didn't exist at compile time, and so it's not an identifier you can use, and it's not a member of the class at all. There was never a matching Dim statement for that name.
What you can do, though, is look again in the Controls collection where you added the TextBox to the form:
Me.Controls("Textbox1")
or
Me.Controls("Textbox1").Text
You may also need to cast the value to a TextBox:
Dim box As TextBox = DirectCast(Me.Controls("Textbox1"), TextBox)
MessageBox.Show(box.Text)
Remember that case matters here.
Further saving this in a DB is out of scope for one question. There are as many ways to do that as there are programmers in the world. You should make your own attempt first, and come back here with a new question when you run into specific problems.
Thank you,
this is my attempt and it is done !
Dim userInput As TextBox = Form1.Controls.Item("TextBox" & i.ToString)
mycommand.Parameters.AddWithValue("#workstation", userInput.Text)
:D
Because you creating dynamic amount of input controls, right tool for the job will be DataGridView control.
Create a class to represent your data
Public Class LineInfo
Public Property Number As Integer
Public Property WorkStationNumber As Integer
End Class
Create `DataGridView in the form designer.
Private Sub btn_OK_lines_number_Click(sender As Object, e As EventArgs) Handles btn_OK_lines_number.Click
Dim linesAmount As Integer
If Integer.TryParse(txt_lines_number.Text, linesAmount) = False Then
MessageBox.Show("please enter a number")
txt_lines_number.Text = ""
Exit Sub
End If
' Create class instance for every line
Dim lines =
Enumerable.Range(1, linesAmount)
.Select(Function(i) New LineInfo With { .Number = i })
.ToList()
'Set lines as DataSource to the DataGridView
Me.DataGridView1.DataSource = lines
End Sub
DataGridView will display all lines and provide input fields to update work station numbers.
You can access updated lines later by casting DataSource back to the List
Dim lines = DirectCast(Me.DataGridView1.DataSource, List(Of LineInfo))
' Now you can access all data and save it to the database
Dim parameters =
lines.Select(Function(line)
Return new SqlParameter With
{
.ParameterName = $"#workstation{line.Number}",
.SqlDbType = SqlDbType.Int,
.Value = line.WorkStationNumber
}
End Function)
.ToList()
myCommand.Parameters.AddRange(parameters)
You can freely change style, font colors of different columns in the datagridview.

Problems with generating labels

The Problem: I'm programmatically generating labels but am having trouble referencing them in code because they don't exist at runtime.
The Context: For a game, I've generated a 10x10 grid of labels with the following:
Public lbl As Label()
Dim tilefont As New Font("Sans Serif", 8, FontStyle.Regular)
Private Sub Lucror_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim i As Integer = 0
Dim a As Integer = 0
Dim height As Integer
Dim width As Integer
height = 30
width = 30
ReDim lbl(99)
For i = 0 To 99
lbl(i) = New Label
lbl(i).Name = i
lbl(i).Size = New System.Drawing.Size(30, 30)
lbl(i).Location = New System.Drawing.Point((width), height)
lbl(i).Text = i
lbl(i).Font = tilefont
Me.Controls.Add(lbl(i))
width = width + 30
a = a + 1 'starting new line if required
If (a = 10) Then
height = height + 30
width = 30
a = 0
End If
Next
End Subenter code here
This worked fine but the labels function as tiles in the game and game tiles need to store 2-3 integers each as well as be able to be referenced through event handlers. I figured a possible way to store integers would be to generate 100 arrays, each named after a label and each holding the 2-3 integers, but that seems very redundant.
What I need:
On click and on hover event handlers for every label
An array (or dictionary?) to store 2-3 integers for every label
Labels have to reference each others names ie. do something to label with name (your name + 1).
The Question: Is there a simple way to achieve these three things with the current way I generate labels (and if so, how?) and if not, how else can I generate the 100 labels to make achieving these things possible?
Any help is much appreciated.
Your labels do exist at runtime, but not at compile time. Attaching events is a little different at runtime, you must use AddHandler.
Below is some sample code that should illustrate everything you're asking for. I've introduced inheritance as a way of saving data that is pertinent to each tile. The GameTile type behaves exactly as a label, and we've added some functionality for storing integers and naming the control.
Public Class Form1
Dim tilefont As New Font("Sans Serif", 8, FontStyle.Regular)
Public Property GameTiles As List(Of GameTile)
Private Sub Lucror_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim a As Integer = 0
Dim xPosition As Integer = 30
Dim yPosition As Integer = 30
GameTiles = New List(Of GameTile)
For i = 0 To 99
Dim gt As New GameTile(i.ToString)
gt.Size = New System.Drawing.Size(30, 30)
gt.Location = New System.Drawing.Point((yPosition), xPosition)
gt.Font = tilefont
gt.Integer1 = i + 1000
gt.Integer2 = i + 2000
gt.Integer3 = i + 3000
Me.Controls.Add(gt)
AddHandler gt.Click, AddressOf TileClickHandler
GameTiles.Add(gt)
yPosition = yPosition + 30
a = a + 1 'starting new line if required
If (a = 10) Then
xPosition = xPosition + 30
yPosition = 30
a = 0
End If
Next
End Sub
Private Sub TileClickHandler(sender As Object, e As EventArgs)
Dim gt = CType(sender, GameTile)
MsgBox("This tile was clicked: " & gt.Text &
Environment.NewLine & gt.Integer1 &
Environment.NewLine & gt.Integer2 &
Environment.NewLine & gt.Integer3)
End Sub
End Class
Public Class GameTile
Inherits Label
'this class should be in a separate file, but it's all together for the sake of clarity
Public Property Integer1 As Integer
Public Property Integer2 As Integer
Public Property Integer3 As Integer
Public Sub New(NameText As String)
MyBase.New()
Name = NameText
Text = NameText
End Sub
End Class

How to do this effect in VB? It works in Python

how can i fix this problem, in line with ">>" , in python it works, how does it work in vb
Public Class frmCafeOrder
Public ingredients = {{"Apple", 10.0},
{"Lettuce", 12.5},
{"Tomato", 8.5},
{"Ham", 20.0},
{"Tuna", 18.5},
{"Grain Wheet", 8.0},
{"Honey Oat", 10.5}}
Public priceControls = {{chkApple, lblApplePrice},
{chkLettuce, lblLettucePrice},
{chkTomato, lblTomatoPrice},
{chkHam, lblHamPrice},
{chkTuna, lblTunaPrice},
{rbGrainWheet, lblGrainWheetPrice},
{rbHoneyOat, lblHoneyOatPrice}}
Private Sub frmCafeOrder_Load(sender As Object, e As EventArgs) Handles MyBase.Load
init()
For i As Integer = 0 To ingredients.GetLength(0)
Dim ingredient = ingredients(i, 0)
>>Dim controls = priceControls(i)
Dim price = ingredients(i, 1)
>>priceControls = controls(i)
>>priceControls = String.Format("HK$ {0}", price)
Next
End Sub
End Class
First, you are trying to use a 2D array without specifying the other dimension.
You specify these perfectly:
Dim ingredient = ingredients(i, 0)
Dim price = ingredients(i, 1)
but are failing to do that with this:
Dim controls = priceControls(i) 'notice it's missing the second dimension
Secondly.... this... whatever this is...
Dim controls = priceControls(i)
priceControls = controls(i)
You are setting controls to priceControls and then trying to set it to itself, but with an added (i), where on earth did the (i) in controls come from?
and then for a little added confusion.
priceControls = controls(i)
priceControls = String.Format("HK$ {0}", price)
why set it to one thing when you are just going to set it to another?
What I am guessing you are trying to do is this:
Go through the list of ingredients in Ingredients()
Populate the right lbl.text field with the corresponding price
For i As Integer = 0 To ingredients.GetLength(0)
Dim ingredient as String = ingredients(i, 0)
Dim price as String = ingredients(i, 1)
Dim lbl as Label = DirectCast(priceControls(i, 1), Label)
lbl.text = String.Format("HK$ {0}", price)
Next
You haven't really specified the problem directly or what you are looking to do, so this is really just my guess at both.

Controls are not added to tabpage VB.NET

I run the following code in the constructor of a window. The "label" gets added but none of the other controls are shown on screen. If I debug the newTab.Controls there are several controls in it. Why don't they show up on the screen and I only see the "label" control.
Thanks
Dim graphlist As ArrayList = New ArrayList
For Each funct As TL_FUNCTION In functionlist
If (funct.functionname = functi) Then
If Not (graphlist.Contains(funct.picture)) Then
graphlist.Add(funct.picture)
End If
End If
Next
For Each picture In graphlist
Dim NewTab As New TabPage
NewTab.Name = picture
NewTab.Text = NewTab.Name
Me.TabControl1.Controls.Add(NewTab)
Me.TabControl1.SelectedIndex = Me.TabControl1.TabCount - 1
For Each func As TL_FUNCTION In functionlist
If (func.picture = picture) Then
Dim label As Label = New Label
label.Text = func.curve.ToString
NewTab.Controls.Add(label) 'This label shows up
Dim key As String
Dim values() As String
For Each key In func.values.Keys
values = func.values.GetValues(key)
For Each value As String In values
Dim label2 As New Label
label2.Text = key.ToString
Dim textb As TextBox = New TextBox
textb.Text = value
NewTab.Controls.Add(label2) 'this one is not shown on the tab
NewTab.Controls.Add(textb) 'this one is not shown on the tab
Next value
Next key
End If
Next
Next
You are placing the new labels and textboxes underneath the new label that you see in the TabPage because you never set their location, so it defaults to point (0, 0).
Try setting the location for the controls:
For Each value As String In values
Dim label2 As New Label
label2.Text = key.ToString
label2.Location = New Point(10, NewTab.Controls.Count * 24)
Dim textb As TextBox = New TextBox
textb.Text = value
textb.Location = New Point(label2.Right + 4, label2.Top)
NewTab.Controls.Add(label2)
NewTab.Controls.Add(textb)
Next value