Find the first empty MaskedTextBox...

Find the first empty MaskedTextBox...

• oneniner

  // I'm new to VisualBasic 2005 Express

  Depending on how new you are, it's likely that my core advice would be the advice I give 20 times a day. If you want to learn to code, you should learn the language before any frameworks, including winforms.

  However. Your form has a Controls collection. You can use foreach to step through it, and you can check if a control is a maskedtextbox, and if it is, you can cast it to that type, and check it's text property.

  Alternatively, you might prefer to build a list containing all your maskedtextboxes, which you could iterate through more simply. Or ( worst case, disgusting code scenario ), just check them one by one.

  
  
  

• andy0203

  William !

  One more thing if I may.

  I written some code to store the values to a .txt file so that when I re-open the form, the values will return (Hopfully to where they came from), but unfortunately, they don't. What happens is, they start back filling from the bottom of the form (Highest "MaskedTextBox" number to the lowest) How can I make them return to where they came from

  Here is the code I'm using:

  Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

  Try

  FileOpen(1, "FSO2.txt", OpenMode.Input)

  Dim Datepick2 As Windows.Forms.Control

  For Each Datepick2 In Me.Controls

  If TypeOf Datepick2 Is MaskedTextBox Then

  FileSystem.Input(1, Datepick2.Text)

  End If

  Next

  FileClose(1)

  Catch ex As Exception

  FileClose(1)

  End Try

  End Sub

  
  

• DuckPuppy

  Hah! You're welcome.
  
  I didn't see your reply before I wrote my other posts to you.
  
  Cheers,
  --William
  
  

• gamemaker9

  Here's another way. We do a one-time sifting of all the form's controls and assemble from that a List of MaskedTextBoxes. From then on, we can simply iterate through the List for the first one with an empty Text property.
  
  Below is the code:
  
  Public Class Form1
  
  Private MyMaskedTextBoxes As New List(Of MaskedTextBox)
  
  Sub New()
  
  ' This call is required by the Windows Form Designer.
  InitializeComponent()
  
  ' Add any initialization after the InitializeComponent() call.
  Me.CollectMaskedTextBoxes()
  
  End Sub
  Private Sub CollectMaskedTextBoxes()
  'we will assemble a collection of Mtbs in numerical order
  
  Dim myStack As New Stack(Of MaskedTextBox)
  
  'let's loop through all controls
  'MaskedTextBoxes will be encountered from Highest to Lowest
  'so we will put them on a stack as we find them and
  'then take them from the stack and put them in the List
  For i As Integer = 0 To Me.Controls.Count - 1
  'let's check each control's Name property to see if
  'the current control is a MaskedTextBox
  Dim pos As Integer
  pos = Me.Controls.Item(i).Name.IndexOf("MaskedTextBox")
  
  If pos <> -1 Then
  'we found a MaskedTextBox control
  
  'let's convert the general control to a MaskedTextBox
  Dim mtb As MaskedTextBox
  mtb = CType(Me.Controls.Item(i), MaskedTextBox)
  
  'let's add this control to our STACK of MaskedTextBoxes
  myStack.Push(mtb)
  
  End If
  Next i
  
  'let's take the Mtbs from the stack and put them in the List
  For i As Integer = 0 To myStack.Count - 1
  Me.MyMaskedTextBoxes.Add(myStack.Pop())
  Next
  
  End Sub
  
  Private Sub FindFirstEmptyMtb(ByVal someText As String)
  'loop through all the Mtbs in the Mtb collection
  For i As Integer = 0 To Me.MyMaskedTextBoxes.Count - 1
  'check Text property of current Mtb
  If Me.MyMaskedTextBoxes.Item(i).Text = String.Empty Then
  'we found the first empty Mtb
  
  'let's supply the text
  Me.MyMaskedTextBoxes.Item(i).Text = someText
  
  'and exit the for loop
  Exit For
  End If
  Next
  End Sub
  
  Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
  Me.FindFirstEmptyMtb("hello")
  End Sub
  End Class
  
  
  

• dpogo

  I also am new to VB Express. I have recently bought $200.00 plus worth of VB books. All of them are good, but two I refer to quite frequently:
  
  Mastering Visual Basic .NET by Evangelos Petroutsos (published by Sybex)
  
  and...
  
  Visual Basic 2005: Programmer's Reference by Rod Stephens (published by Wrox)
  
  Another good one is (it's a little less in-depth)...
  
  Beginning Visual Basic 2005 by Thearon Willis, Bryan Newsome (also published by wrox)
  
  
  I got them at BooksAMillion/Barnes&Noble. If you have trouble getting out, I have inserted links to amazon.com...you could get them online and have them delivered to your house.
  
  You can get by on only one of those books. They all provide fairly in-depth coverage and similar information. So, you can spend just $50.00 instead of $200.00.
  
  --William
  
  

• Kyle Fender

  William !

  Thankyou.Thankyou,Thankyou...Did I say Thankyou

  You are one steely eye'd master of code prestidigitation!

  You are the best

  (Grovel,Grovel,Grovel!)

  P.S. I'll get a few good books!

  Mike C.

  
  

• TheReverend

  one way is to loop through all the controls on the form and check two things
  

  1. first check the control's name. If its a MaskedTextBox, then...
  2. ...check the Text property. If its Text property is empty, you've found it

  however, you must be sure that the MaskedTextBoxes were placed on the form in numerical order for the following code to work.
  
  I have provided the whole class code as it was short and I had to write it anyway to test it.
  
  Public Class Form1
  
  Sub FindFirstEmptyMaskedTextBox(ByVal desiredText As String)
  Dim ControlNameBase As String = "MaskedTextBox"
  
  'let's set up a while loop
  Dim foundIt As Boolean = False
  Dim MaskedTextBoxCounter As Integer = 1
  While Not foundIt
  Dim ControlName As String
  ControlName = ControlNameBase & MaskedTextBoxCounter
  
  'let's loop through all the controls on this form
  'remember collections are usually zero based
  For ControlCounter As Integer = 0 To Me.Controls.Count - 1
  If Me.Controls.Item(ControlCounter).Name = ControlName Then
  'we found a MaskedTextBox control
  'let's test for empty string
  If Me.Controls.Item(ControlCounter).Text = String.Empty Then
  'we found the first empty one
  'let's supply desired text
  Me.Controls.Item(ControlCounter).Text = desiredText
  
  'and let's exit the while loop
  foundIt = True
  End If
  End If
  Next ControlCounter
  
  MaskedTextBoxCounter += 1
  
  End While
  
  End Sub
  
  Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
  'I put a button on the form to run the subroutine above
  Me.FindFirstEmptyMaskedTextBox("hello")
  End Sub
  End Class
  
  cheers,
  --william
  
  
  
  
• Find the first empty MaskedTextBox...