TextBox

Question

I have been using the designer to add textbox to my projects. I then have to hide them. What is the correct code to creating a textbox that I can use to pass and store data?

Answer 1

A textbox for what?

Phone, Office, Windows Forms, a Web page, WPF, ..............................................................................

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Success
Cor

Answer 2

I have been using the designer to add textbox to my projects. I then have to hide them. What is the correct code to creating a textbox that I can use to pass and store data?

Don't use a textbox to pass and store data.  Use it to display some text or to obtain text input from the user.  Use variables to store and pass data.  You create a textbox using a constructor -

  Dim TB As New TextBox

To associate a textbox with a form so it shows on the form add it to the form's control collection (or the control collection of whatever container you are putting it in).
http://msdn.microsoft.com/en-us/library/system.windows.forms.control.controls(v=vs.110).aspx

Answer 3

Hello,

As already mentioned, using a TextBox for passing and storing information is not a good idea. Instead consider using a List(Of T) i.e.

Private MyList As New List(Of String)

Or perhaps the list might store strong typed data for a class i.e.

Public Class Perrson
    Public Property FirstName As String
    Public Property LastName As String
    Public Sub New()
    End Sub
End Class

Adding items

Private PersonList As New List(Of Person)
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    PersonList.Add(New Person With {.FirstName = "Karen", .LastName = "Payne"})
End Sub

If you need to pass this to another class, module, form or function that is easily done. 

Best to explain what you need to do and if you are set on creating a bunch of TextBox controls any ways we can still assist. For example, create a bunch of TextBox controls

Public Class TextBoxCreate
    Public Property TextBoxes As TextBox()
    Public Property TextBoxBaseName As String
    Public Property TextBoxCount As Integer
    Public Property ParentControl As Control

    Public Sub New(
        ByVal ParentControl As Control,
        ByVal BaseName As String,
        ByVal Count As Integer)

        Me.ParentControl = ParentControl
        Me.TextBoxBaseName = BaseName
        Me.TextBoxCount = Count

    End Sub
    Public Sub CreateTextBoxes()
        Dim Base As Integer = 10
        TextBoxes = Enumerable.Range(0, TextBoxCount).Select(
            Function(Indexer)

                Dim b As New TextBox With
                    {
                        .Name = String.Concat(TextBoxBaseName, Indexer),
                        .Text = Base.ToString,
                        .Width = 150,
                        .Location = New Point(25, Base),
                        .Parent = Me.ParentControl,
                        .Visible = False
                    }

                Me.ParentControl.Controls.Add(b)

                Base += 30

                Return b

            End Function).ToArray

    End Sub
End Class

Simple usage

Private tbs As New TextBoxCreate(Me, "txt", 20)

The above to be modified to allow data to be passed in rather than number of TextBox controls to create and then iterate thru the list and create that many TextBox controls but as mentioned earlier it is better not to use TextBox controls this way, it's how some did work back in VB6 and there are much better methods today.

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Answer 4

So if I have a function that is creating a value to a variable in a sub and I want to store that in a table,  where would I store the value as it is changing before I collet it to be added to the table?  I would have passed it to a textbox and then stored that value   by referring to the textbox not the variable. 

Answer 5

Hello,

Like this

Public Class Form1
    Private NameList As New List(Of String)
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim FullName As String = GetName()
        If FullName IsNot Nothing Then
            NameList.Add(FullName)
        Else
            MessageBox.Show("Requires first and last name")
        End If
    End Sub
    ''' <summary>
    ''' This is hard coded for demoing
    ''' </summary>
    ''' <returns></returns>
    ''' <remarks></remarks>
    Private Function GetName() As String
        If Not String.IsNullOrWhiteSpace(txtFirstName.Text) AndAlso Not String.IsNullOrWhiteSpace(txtLastName.Text) Then
            Return String.Concat(txtFirstName.Text, " ", txtLastName.Text)
        Else
            Return Nothing
        End If
    End Function
    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        For Each FullName In NameList
            '
            ' Do something with the item
            '
        Next
    End Sub
End Class

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Answer 6

So if I have a function that is creating a value to a variable in a sub and I want to store that in a table,  where would I store the value as it is changing before I collet it to be added to the table?

If you have a variable that needs to be referred to from several different pieces of code within a form, then declare that variable at the form level. It will then be available to any code that is part of that form. 

Public Class Form4

    Dim TableItem As String = ""

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
         'etc

See: http://msdn.microsoft.com/en-us/library/1t0wsc67.aspx

Answer 7

But,  what about multiple forms?  I am trying to pass from one form to another and used textbox to do so.  Do I declare a class on a form?  This effort didn't seem to work.

I just found declaring it as a Public variable.  As for A Class should I be able to do this as well?

Answer 8

But,  what about multiple forms?  I am trying to pass from one form to another and used textbox to do so.

If you need to access information between forms then you must use one of the available processes for passing that data back and forth.  There are some examples here:

http://vbdotnetblog.wordpress.com/forms/

Another option is to create a shared variable in a module. See:

http://msdn.microsoft.com/en-us/library/7825002w(v=vs.90).aspx

If you have been using form controls to pass data then you were probably relying on the default form instance (which is a shared instance of your form that is created automatically for you).  This approach is simple to start with but quickly becomes unmanageable and unreliable.  It only exists because it was the way it used to be done in previous versions of VB that did not properly support objects.

Answer 9

Hello,

To set the Text property from a child form we can set the Owner when creating the child form then in the child assign text to the TextBox in the parent form TextBox.

Both forms have a TextBox1

Parent form

Public Class Form1
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim f As New Form2 With {.Owner = Me}
        Try
            f.ShowDialog()
        Finally
            f.Dispose()
        End Try
    End Sub
End Class

Child form

Public Class Form2
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        CType(Me.Owner, Form1).TextBox1.Text = Me.TextBox1.Text
    End Sub
End Class

We can use a Singleton pattern (if you know C# it's similar to a static class). In short the class is created once and used throughout the project. We could even place the code in a class project in the same solution and use it.

Class to use

Public Class Person
    Public Property Identifier As Integer
    Public Property FirstName As String
    Public Property LastName As String
    Public ReadOnly Property FullName As String
        Get
            Return FirstName & " " & LastName
        End Get
    End Property
    Public Sub New()
    End Sub
End Class

Singleton class

Public Class Example1
    Private Shared _Instance As Example1
    ''' <summary>
    ''' Only executes first time
    ''' </summary>
    ''' <remarks></remarks>
    Protected Sub New()
        People = New List(Of Person)
    End Sub
    Public ReadOnly Property Count As Integer
        Get
            Return People.Count
        End Get
    End Property
    Public Sub Clear()
        People.Clear()
    End Sub
    Public Sub Add(ByVal sender As Person)
        Dim ExistTest = (From p In People Where p.Identifier = sender.Identifier).FirstOrDefault
        If ExistTest Is Nothing Then
            People.Add(sender)
        End If
    End Sub
    Public Shared Function Instance() As Example1
        If _Instance Is Nothing Then
            _Instance = New Example1
        End If
        Return _Instance
    End Function
    Public Property People As List(Of Person)
End Class

Form1 (parent)

Public Class Form1
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim f As New Form2
        Try
            f.ShowDialog()
        Finally
            f.Dispose()
        End Try
    End Sub
    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        If Example1.Instance.Count > 0 Then
            MessageBox.Show(Example1.Instance.People.First.FullName)
        Else
            MessageBox.Show("Need to show form2")
        End If
    End Sub
End Class

Form2 (child)

Public Class Form2
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Example1.Instance.People.Add(
            New Person With
            {
                .Identifier = 1,
                .FirstName = "Karen",
                .LastName = "Payne"
            }
        )
    End Sub
End Class

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Please remember to mark the replies as answers if they help and unmark them if they provide no help, this will help others who are looking for solutions to the same or similar problem.