Calculate multi TextBoxes

Question

I have few TextBoxes and i need to calculate sum of all of them into another TextBox or Label, any suggestions? Name of the TextBoxes are: TextBox1, TextBox2 and so on. It is a regular TextBoxes without any data on it.

Answer 1

Hello @DRGAGI

A very simple example, using a class named Item and NumericTextBox (custom TextBox for ensuring only numerics are used and is a very basic TextBox). Full source code is in this GitHub repository.

Class implementing INotifyPropertyChanged.

Imports System.ComponentModel  
Imports System.Runtime.CompilerServices  
  
Public Class Item  
    Implements INotifyPropertyChanged  
    Private _value1 As Integer  
    Private _value2 As Integer  
    Private _value3 As Integer  
    Private _value4 As Integer  
  
    Public Property Value1() As Integer  
        Get  
            Return _value1  
        End Get  
        Set  
            _value1 = Value  
            OnPropertyChanged()  
        End Set  
    End Property  
  
    Public Property Value2() As Integer  
        Get  
            Return _value2  
        End Get  
        Set  
            _value2 = Value  
            OnPropertyChanged()  
        End Set  
    End Property  
  
    Public Property Value3() As Integer  
        Get  
            Return _value3  
        End Get  
        Set  
            _value3 = Value  
            OnPropertyChanged()  
        End Set  
    End Property  
  
    Public Property Value4() As Integer  
        Get  
            Return _value4  
        End Get  
        Set  
            _value4 = Value  
            OnPropertyChanged()  
        End Set  
    End Property  
  
    Public ReadOnly Property Total() As Integer  
        Get  
            Return Value1 + Value2 + Value3 + Value4  
        End Get  
    End Property  
    Public Event PropertyChanged As PropertyChangedEventHandler Implements INotifyPropertyChanged.PropertyChanged  
    Protected Overridable Sub OnPropertyChanged(<CallerMemberName> Optional memberName As String = Nothing)  
        RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(memberName))  
    End Sub  
End Class  

Numeric TextBox

Option Infer On  
  
Imports System  
Imports System.ComponentModel  
Imports System.Windows.Forms  
  
''' <summary>  
''' TextBox which only accepts numeric values along with asserting data copied from the Windows Clipboard  
''' </summary>  
Public Class NumericTextBox  
    Inherits TextBox  
  
    Private WM_KEYDOWN As Integer = &H100  
    Private WM_PASTE As Integer = &H302  
    ''' <summary>  
    ''' Handle key presses for non numeric data  
    ''' </summary>  
    ''' <param name="msg">Window message</param>  
    ''' <returns>bool from base</returns>  
    Public Overrides Function PreProcessMessage(ByRef msg As Message) As Boolean  
        If msg.Msg = WM_KEYDOWN Then  
            Dim keys As Keys = CType(msg.WParam.ToInt32(), Keys)  
  
            Dim numbers As Boolean = ((keys >= Keys.D0 AndAlso keys <= Keys.D9) OrElse  
                                      (keys >= Keys.NumPad0 AndAlso keys <= Keys.NumPad9)) AndAlso  
                                     ModifierKeys <> Keys.Shift  
  
            Dim ctrl As Boolean = keys = Keys.Control  
  
            Dim ctrlZ As Boolean = keys = Keys.Z AndAlso ModifierKeys = Keys.Control,  
                ctrlX As Boolean = keys = Keys.X AndAlso ModifierKeys = Keys.Control, ctrlC As Boolean = keys = Keys.C AndAlso  
                    ModifierKeys = Keys.Control, ctrlV As Boolean = keys = Keys.V AndAlso  
                    ModifierKeys = Keys.Control, del As Boolean = keys = Keys.Delete,  
                bksp As Boolean = keys = Keys.Back, arrows As Boolean = (keys = Keys.Up) Or (keys = Keys.Down) Or  
                                                                        (keys = Keys.Left) Or (keys = Keys.Right)  
  
            If numbers Or ctrl Or del Or bksp Or arrows Or ctrlC Or ctrlX Or ctrlZ Then  
                Return False  
  
            ElseIf ctrlV Then  
                ' handle pasting from clipboard  
                Dim clipboardData = Clipboard.GetDataObject()  
                Dim input = DirectCast(clipboardData.GetData(GetType(String)), String)  
                For Each character In input  
                    If Not Char.IsDigit(character) Then  
                        Return True  
                    End If  
                Next character  
                Return False  
            Else  
                Return True  
            End If  
        Else  
            Return MyBase.PreProcessMessage(msg)  
        End If  
    End Function  
  
    <Browsable(False)>  
    Public ReadOnly Property AsInteger() As Integer  
        Get  
            Dim value As Integer  
            If Integer.TryParse(Text, value) Then  
                Return value  
            Else  
                Return 0  
            End If  
        End Get  
    End Property  
    ''' <summary>  
    ''' Monitor for non-numeric pasted from clipboard  
    ''' </summary>  
    ''' <param name="m">Windows message <see cref="Message"/></param>  
    Protected Overrides Sub WndProc(ByRef m As Message)  
        If m.Msg = WM_PASTE Then  
            Dim clipboardData = Clipboard.GetDataObject()  
            Dim input = CStr(clipboardData?.GetData(GetType(String)))  
            For Each character In input  
                If Not Char.IsDigit(character) Then  
                    m.Result = New IntPtr(0)  
                    Return  
                End If  
            Next character  
        End If  
  
        MyBase.WndProc(m)  
  
    End Sub  
End Class  

Form code

Imports System.ComponentModel  
  
Public Class Form1  
    Private BindingList As New BindingList(Of Item)  
  
    Private Sub Form1_Shown(sender As Object, e As EventArgs) Handles Me.Shown  
        BindingList = New BindingList(Of Item) From {New Item() With  
            {.Value1 = 12, .Value2 = 3, .Value3 = 100, .Value4 = 6}}  
  
        NumericTextbox1.DataBindings.Add("Text", BindingList, "Value1")  
        NumericTextbox2.DataBindings.Add("Text", BindingList, "Value2")  
        NumericTextbox3.DataBindings.Add("Text", BindingList, "Value3")  
        NumericTextbox4.DataBindings.Add("Text", BindingList, "Value4")  
        NumericTextbox5.DataBindings.Add("Text", BindingList, "Total")  
    End Sub  
End Class  

Edit: Dynamic version of the above

Since you have more TextBoxes then originally thought the following uses a language extension (can be done without an extension yet this is cleaner and usable in any project) to get all NumericTextBoxes into a list. The only downside to this is you need to replace you current TextBox controls with the one I use.

Namespace Classes  
    Public Module ControlExtensions  
        <Runtime.CompilerServices.Extension>  
        Public Iterator Function Descendants(Of T As Class)(control As Control) As IEnumerable(Of T)  
            For Each child As Control In control.Controls  
  
                Dim currentChild = TryCast(child, T)  
                If currentChild IsNot Nothing Then  
                    Yield currentChild  
                End If  
  
                If child.HasChildren Then  
                    For Each descendant As T In child.Descendants(Of T)()  
                        Yield descendant  
                    Next  
                End If  
            Next  
  
        End Function  
        <Runtime.CompilerServices.Extension>  
        Public Function NumericTextBoxList(pControl As Control) As List(Of NumericTextBox)  
            Return pControl.Descendants(Of NumericTextBox)().ToList()  
        End Function  
  
        ''' <summary>  
        ''' Get names of controls   
        ''' </summary>  
        ''' <param name="pControls"></param>  
        ''' <returns></returns>  
        <Runtime.CompilerServices.Extension>  
        Public Function ControlNames(pControls As IEnumerable(Of Control)) As String()  
            Return pControls.Select(Function(c) c.Name).ToArray()  
        End Function  
  
    End Module  
End Namespace  

Here is all you need in the form.

Public Class Form1  
    Private BindingList As New BindingList(Of Item)  
  
    Private Sub Form1_Shown(sender As Object, e As EventArgs) Handles Me.Shown  
  
        BindingList = New BindingList(Of Item) From {New Item() With  
            {.Value1 = 0, .Value2 = 0, .Value3 = 0, .Value4 = 0}}  
  
        For Each numericTextBox As NumericTextBox In NumericTextBoxList  
            Dim index = Integer.Parse(Regex.Replace(numericTextBox.Name, "[^\d]", ""))  
            numericTextBox.DataBindings.Add("Text", BindingList, $"Value{index}")  
        Next  
  
        TotalLabel.DataBindings.Add("Text", BindingList, "Total")  
    End Sub  
End Class  

Note that I use a Label for total this time but could also use a regular TextBox.

Summary

We are developers strive to write short, efficient and concise which is all well and good yet short is not always efficient and concise. Then there needs to be a willingness to refactor rather than try to fit a square peg in a around hole. Which brings me to the following point, when I post code it's for your benefit, not mine to allow you and others become better coders.

Source code has been updated to match the edit section above.

Answer 2

Hi

Try this as a stand alone example and see if it helps.

' Blank FORM1 
Option Strict On
Option Explicit On
Public Class Form1
    Dim lab As New Label
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        ' ==========================
        ' this code block is ONLY for
        ' this example - you have your
        ' controls already on the Form
        Dim y As Integer = 20
        For i As Integer = 1 To 6
            Dim tb As New TextBox
            With tb
                .Location = New Point(20, y)
                .Width = 100
                Controls.Add(tb)
                AddHandler tb.TextChanged, AddressOf TextBox_TextChanged
                y += tb.Height + 4
            End With
        Next
        With lab
            .Location = New Point(160, 20)
            .AutoSize = True
            .Font = New Font(.Font.FontFamily, 20)
            Controls.Add(lab)
        End With
        ' ==========================
    End Sub

    ' you could probably use thse two 
    ' Subs as a possible answer to
    ' your question
    Private Sub TextBox_TextChanged(sender As Object, e As EventArgs)
        Dim total As Double = 0.0
        For Each c As Control In Controls
            If c.GetType = GetType(TextBox) Then
                total += GetDouble(c.Text)
            End If
        Next
        lab.Text = total.ToString("0.00")
    End Sub
    Function GetDouble(s As String) As Double
        Dim v As Double = 0.0
        If Double.TryParse(s, v) Then Return v
        Return 0.0
    End Function
End Class

Answer 3

Private Sub Button25_Click(sender As Object, e As EventArgs) Handles Button25.Click
        TextBox73.Text = Val(TextBox49.Text) + Val(TextBox50.Text) + Val(TextBox51.Text) + Val(TextBox52.Text) + Val(TextBox53.Text) + Val(TextBox54.Text) + Val(TextBox55.Text) + Val(TextBox56.Text) + Val(TextBox57.Text) + Val(TextBox58.Text) + Val(TextBox59.Text) + Val(TextBox60.Text) + Val(TextBox61.Text) + Val(TextBox62.Text) + Val(TextBox63.Text) + Val(TextBox64.Text) + Val(TextBox65.Text) + Val(TextBox66.Text) + Val(TextBox67.Text) + Val(TextBox68.Text) + Val(TextBox69.Text) + Val(TextBox70.Text) + Val(TextBox71.Text) + Val(TextBox72.Text)
    End Sub

Is this correct way? Looks like it works fine

Answer 4

I want to thank you all for your time and help. You helping me a lot to learn and understand programming. I don't have school of programming because i work too hard and have no time to take some courses to learn, everything i learned is via internet, youtube... This is something that inspiring me and relax me after work. I hope one day i become more experienced and understand better programming language. You are great, thank you again.
I have so many questions to ask, but i will post them as my project grow and come with new situations.

Answer 5

First up when you drop a text box onto the form, the form designer will "cook up" and give the text box control a name. So you have TextBox64 etc. You can work with those names - but they are hard to work with in code.

So we do have 10 text boxes "1 to 10". But as you can see, the names above are quite messy.

So, when you drop a text box, let’s give each text box a name, and start with T1, then T2, then T3 etc.

You can use any name - but "T" is nice and short - saves the keyboard!!

So, click on the first text box (our number one), and change the text box name to something that ends with “1”.

So, we use T1, then T2, then T3 all the way up to T10

When you click on a text box, display the property sheet. And you can thus change the name here:

So, in above, let’s change then second selected Textbox to T2.

So this for the 10 boxes. (first one T1, then T2 and then so on!).

And lets rename our total text box.

Let’s call it MyTotalBox

Now, our code to add up the 10 boxes becomes this:

       Dim MyTotal As Double = 0  
  
        Dim strTbox As String  
  
        For i = 1 To 6  
            strTbox = "TextBox" & i  
            If Controls(strTbox).Text <> "" Then  
                MyTotal = MyTotal + Controls(strTbox).Text  
            End If  
        Next  
  
        ' put our total in the text box called MyTotal  
        MyTotalBox.Text = MyTotal  
  

And note the simple check for if the text box is blank.

Now, of course over time, one would improve this system, and perhaps reject non numbers in each text box. But, for a BASIC solution (pun intended!!!) then the above will give you some really nice simple tips.

First up, note how we stuffed a value (string) into a simple variable. Then we used that simple string value to “reference” the control on the form.

In most cases, you can in code just type in the control name, but since we had 10 of them, and since we gave them a “name convention”, then we can now use a for/next loop on those controls.

As you journey down this road of learning to code?

Well, there is ALWAYS more things to learn.

So, is what you have and wrote the right way? Well, it worked! And that gave you a shot of happy juice. And without those small shots happy and seeing your code run? Seeing your code do something?

Well, that is just pure joy – not much else can beat the feeling of typing in a bit of code, just a small amount and then seeing and feeling the results.

And without the above fun shots? Then you not take the next step, the next road, and the next leap in learning about coding.

Now, we can/could do a MUCH better number check. Once you have the above working (try it!!! - its fun, its short, it is sweet!!!).

Now we can introduce a more robust number check. We can change the above code to this:

      Dim MyTotal As Double = 0  
        Dim MyCheckNumber As Double = 0  
  
        Dim strTbox As String  
  
        For i = 1 To 6  
            strTbox = "TextBox" & i  
            If Double.TryParse(Controls(strTbox).Text, MyCheckNumber) Then  
                MyTotal = MyTotal + MyCheckNumber  
            End If  
        Next  
  
        ' put our total in the text box called MyTotal  
        MyTotalBox.Text = MyTotal  

So, in above we introduced a more advanced feature. it is called TryParse. And you can use it to check/test if the value in the text box is in fact a actual number that passes the mustard seed test! If the condition fails, then the expression is false, and we skip. If the value is a number, then it "stuffs" the result of the valid conversion into our variable called MyCheckNumber.

Enjoy! - and don't forget to try fun things, and simple things - I have fond memories of my first coding experiences - years later I never dreamed about what we can now do with computers. I went on to do computing science, wrote interactive oil spill simulations for oil companies, and much much more!

But, it all starts out as baby steps. And without the fun, without the simple - then it becomes rather hard to climb these steps - the steps of you first starting to write code! - what a joy!

Regards,
Albert D. Kallal (Access MVP 2003-2017)
Edmonton, Alberta Canada