Im coding in VB.Net and trying to have a textbox which displays price with a $ sign. I have gotten it to where the textbox would be empty and once the user puts in a number the sign would show. But I cant add it to the textbox which gets its data from the datasource. If you could lead me towards the direction to get it to show up in the textbox that would be great thanks.
You could try the reulting visual behavior of a MaskedTextBox control
With for example this mask:
MaskedTextBox1.Mask = "9999999999$"
Then, to get a integer value when the text has changed:
Private Sub MaskedTextBox1_TextChanged(sender As Object, e As EventArgs) _
Handles MaskedTextBox1.TextChanged
Dim mtb As MaskedTextBox = DirectCast(sender, MaskedTextBox)
Dim intValue As Integer
If Integer.TryParse(mtb.Text.Replace("$"c, "").Replace(" "c, ""), intValue) Then
Console.WriteLine(intValue)
End If
End Sub
Related
I'm new to visual basic and programming in general, but I'm trying to make a statistic counter sort of program. I'm trying to use a variable to reference a textbox, for example, k_kills(i) = txtKills(i).Text. This doesn't work, however, so I then tried the following:
For i = 0 To 8
Dim tempBox As TextBox
Dim tempName As String = "txtKills" & i.ToString
tempBox = Me.Controls.Item(tempName)
k_kills(i) = tempBox.Text
Next
This also doesn't work and spits out an error each time saying that 'tempBox was Nothing'.
Can anyone tell me if I can make this work?
Thanks.
You will need to find the control in some collection. By default the control would exist in its parent's Controls property and since you're trying to get the control by its name then you could use ControlCollection's Find method. If you can guarantee that the control's parent is the Form then you'd call:
Dim tempBox As TextBox = DirectCast(Me.Controls.Find(tempName, False), TextBox)
But if there is the possibility that the control's parent is something other than the Form then you'd call:
Dim tempBox As TextBox = DirectCast(Me.Controls.Find(tempName, True), TextBox)
The first would execute slightly quicker because it only iterates over the current ControlCollection whereas the second could take longer because if it cannot find the control in the current ControlCollection then it starts to iterate over the child controls as well.
Assuming the controls are all in Form as parent and they all start with txtKills...
If you are going to use these text boxes as a group for several actions you may want to build an array or list of TextBox.
Dim Kills(7) As TextBox
Private Sub CreateTextBoxArray()
Dim index As Integer
For Each ctrl As Control In Controls
If ctrl.Name.StartsWith("txtKills") Then
Kills(index) = DirectCast(ctrl, TextBox)
index += 1
End If
Next
End Sub
Private Sub ClearKillTextBoxes()
For Each t In Kills
t.Clear()
Next
End Sub
Private Function GetTextFromKillBoxes() As List(Of String)
Dim lst As New List(Of String)
For Each t In Kills
lst.Add(t.Text)
Next
Return lst
End Function
After Mary's comment I edit my answer to add this line --> My code does not work if Option Strict is On and 'For' starting in 0 or 1 or any number and txtKills[X] exists.
This was my previous answer and I don't know if I have to delete or not:
Your code works fine but I think you have an error because your For starts in 0 and you don't have any "txtKills0". I've tested it now:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim k_kills(10) As String '<< Ignore the length
For i = 1 To 7
Dim tempBox As TextBox
Dim tempName As String = "txtKills" & i.ToString
tempBox = Me.Controls.Item(tempName)
k_kills(i) = tempBox.Text
MsgBox(k_kills(i))
Next
End Sub
I have a form with about 20 controls on it (ComboBox, TextBox, etc) that I have pre-loaded with data. This is being displayed to the user and gives them the capability to change any of the fields.
I do not know the best way of recognizing that changes have taken place. After some research, I found TextBox.TextChanged and setting the flag IsDirty = True or something along those lines.
I don't think this will be 100% bulletproof since the user might change the value and then go back and change it to how it was when initially loaded. I've been thinking about saving the current data to .Tag and then comparing it with the .Text that was entered when the user clicks "Cancel" to simply ask them if they'd like to save the changes.
This is my code:
Private Sub Form1_Load(ByVal sender as Object, byVal e as System.EventArgs)Handles MyBase.Load
For Each ctr as Control in me.Controls
if typeof ctr is TextBox then
ctr.tag=ctr.text
end if
Next
End Sub
This is the code for when the user clicks "Cancel":
Private Sub CmdCancel_Click (ByVal sender as Object, ByVal e As System.EventArgs) Handles CmdCancel.Click
For each ctr As Control in Me.Controls
If Typeof ctr is Textbox then
if ctr.tag.tostring <> ctr.text then
MsgBox ("Do you want to save the items", YesNo)
end if
End if
Next
End sub
Is this an effective way to do this? Can it be relied on? If anyone has any better idea, I'd love to hear it.
Have a look at this:
For Each txtBox In Me.Controls.OfType(Of TextBox)()
If txtBox.Modified Then
'Show message
End If
Next
EDIT
Have a look at this. This may be of interest to you if you wanted an alternative way to the .Tag property:
'Declare a dictionary to store your original values
Private _textboxDictionary As New Dictionary(Of TextBox, String)
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
'You would place this bit of code after you had set the values of the textboxes
For Each txtBox In Me.Controls.OfType(Of TextBox)()
_textboxDictionary.Add(txtBox, txtBox.Text)
Next
End Sub
Then use this to find out the original value and compare to the new value:
For Each txtBox In Me.Controls.OfType(Of TextBox)()
If txtBox.Modified Then
Dim oldValue = (From kp As KeyValuePair(Of TextBox, String) In _textboxDictionary
Where kp.Key Is txtBox
Select kp.Value).First()
If oldValue.ToString() <> txtBox.Text Then
'Show message
End If
End If
Next
I know this already has an accepted answer, but I thought the part about checking if the actual text value has changed should be addressed. Checking modified will reveal if any changes were made to the text, but it will fail if the user, for example, adds a character and then deletes it. I think a good way to do this would be with a custom control, so here's an example of a simple control that stores the textbox's original text whenever it is changed programmatically, and has a textaltered property that can be checked to show whether or not the user's modifications actually resulted in the text being different from its original state. This way, each time you fill the textbox with data yourself, the value you set is saved. Then when you are ready, you just check the TextAltered property:
Public Class myTextBox
Inherits System.Windows.Forms.TextBox
Private Property OriginalText As String
Public ReadOnly Property TextAltered As Boolean
Get
If OriginalText.Equals(MyBase.Text) Then
Return False
Else
Return True
End If
End Get
End Property
Public Overrides Property Text As String
Get
Return MyBase.Text
End Get
Set(value As String)
Me.OriginalText = value
MyBase.Text = value
End Set
End Property
End Class
What i want is when i input a number in texbox1.text like for example i enter 3 it should show 3 textbox but i always get an error. and also i have to save it in database but i dont know how. Help Please..
Private boxes(TextBox1.text) As TextBox
Private Sub Form2_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim newbox As TextBox
For i As Integer = 1 To TextBox1.Text
newbox = New TextBox
newbox.Size = New Drawing.Size(575, 35)
newbox.Location = New Point(10, 10 + 35 * (i - 1))
newbox.Name = "TextBox" & i
newbox.Text = newbox.Name
'connect it to a handler, save a reference to the array and add it to the form controls
AddHandler newbox.TextChanged, AddressOf TextBox_TextChanged
boxes(i) = newbox
Me.Controls.Add(newbox)
Next
End Sub
OK. The error I get when I try to run your code is :-
An unhandled exception of type 'System.InvalidCastException' occurred in Microsoft.VisualBasic.dll
Additional information: Conversion from string "" to type 'Integer' is not valid.`
This is because you're trying to start a loop using a string as the termination index for the loop. Try using
For i As Integer = 1 To Val(TextBox1.Text)
your next problem will depend on how you've declared boxes. If you have declared it like this ..
Dim boxes() As TextBox
You'll end up with a Null reference exception because when you declared boxes, you didnt supply any elements. To remedy this you'll need to add this just before your loop ..
ReDim Preserve boxes(Val(TextBox1.Text))
If boxes is a list.. and to be honest .. thats a better choice than an array, instead of the above line you'll need to change
boxes(i) = newbox
to
boxes.Add(newbox)
You might also need to change other code associated with boxes, but the work will be worth it.
Your biggest problem is that you're trying to get a value from a TextBox that hasn't even appeared yet. You've put your code inside the form's load event. It really needs to be in a separate method. Oh and rather than use the TextBox.changed event you should use a button control to execute the method. Otherwise it's too easy for someone to change the number in the textbox. With your code, each time the textbox is changed (deleting a digit or adding another digit), more TextBoxes will be added and you could end up with lots of them.
So possible final code should look like ..
Public Class Form1
Dim boxes As New List(Of TextBox)
Private Sub Addbuttons(buttonCount As Integer)
Dim newbox As TextBox
For i As Integer = 1 To buttonCount
newbox = New TextBox
newbox.Size = New Drawing.Size(575, 35)
newbox.Location = New Drawing.Point(10, 10 + 35 * (i - 1))
newbox.Name = "TextBox" & i
newbox.Text = newbox.Name
'connect it to a handler, save a reference to the array and add it to the form controls
boxes.Add(newbox)
Me.Controls.Add(newbox)
Next
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Addbuttons(Val(TextBox1.Text))
End Sub
End Class
I'm new to VB.NET and have been struggling all afternoon with something. I've found similar questions on the forum but none of them seemed to describe my problem exactly. I'm fairly sure that I'm missing something very basic.
I have made a main form which currently holds only one button which purpose is to open up a second form and close the main form. Based on the settings the user will select on the 2nd form the first form might have to be adapted to match with the new settings. But the problem occurs even before that.
The 'settings' form has 15 textboxes which I drew onto the form in development mode. They are called ID1, ID2,..,ID15. The values which I want to display in there are saved in an array:
Dim ids(15) as integer
Next, I created a module to simulate what you could call a control array as I used to use them in VB6.
Public sources() As TextBox = [frmSettings.ID1, frmSettings.ID2, //and so on
I did this to be able to iterate through all the 15 textboxes:
For i = 0 To 14
Sources(i).Text = ids(i + 1)
Next
Then I added on the main form this code to the Button1_Click() event:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
frmSettings.Show()
Me.Close()
End Sub
I did the same thing for the 'exit ' button on the frmSettings form.
This seems to work, but only once. I launch the application, push the button and frmSettings pops up and shows all the values from the array in the textboxes. When I push the 'close' button, I return to the main page.
So far so good, but if I try to return to frmSettings a second time, all the textboxes remain blank as if the code I added to the form never gets executed.
Any help would be greatly appreciated!
First, make sure the array that holds your data is accessible to both forms:
Module Module1
Public ids(15) As Integer
End Module
There should not be a declaration for "ids" in either form.
Next, make frmSettings itself responsible for loading and saving the data:
Public Class frmSettings
Private Sub frmSettings_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim matches() As Control
For i As Integer = 0 To 14
matches = Me.Controls.Find("ID" & (i + 1), True)
If matches.Length > 0 AndAlso TypeOf matches(0) Is TextBox Then
Dim TB As TextBox = DirectCast(matches(0), TextBox)
TB.Text = ids(i)
End If
Next
End Sub
Private Sub btnSave_Click(sender As Object, e As EventArgs) Handles btnSave.Click
Dim valid As Boolean = True
Dim matches() As Control
For i As Integer = 0 To 14
matches = Me.Controls.Find("ID" & (i + 1), True)
If matches.Length > 0 AndAlso TypeOf matches(0) Is TextBox Then
Dim TB As TextBox = DirectCast(matches(0), TextBox)
Dim value As Integer
If Integer.TryParse(TB.Text, value) Then
ids(i) = value
Else
MessageBox.Show(TB.Name & ": " & TB.Text, "Invalid Value", MessageBoxButtons.OK, MessageBoxIcon.Warning)
valid = False
End If
End If
Next
If valid Then
Me.Close()
End If
End Sub
End Class
I have some DataGridView code written in vb.net. (Nothing is attached to a datasource.)
The 4th column is a checkboxCell. How do I detect if that checkBox is checked or unchecked?
This code strangely reports TRUE or FALSE at random times. It even turns ON the checkbox in rows other than the row I clicked in.
Private Sub DataGridView1_CellContentClick(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DataGridView1.CellContentClick
Dim whichGrid As DataGridView = CType(sender, DataGridView)
Dim rowClicked As Int16 = e.RowIndex
Call MsgBox(rowClicked & vbCrLf & whichGrid.Rows(rowClicked).Cells(4).Value)
End Sub
All the other examples I've looked at here (and elsewhere) don't seem to help. Their solutions are always:
Just check the cell's VALUE.
Just learn c#, and learn to convert it to vb.net.
Just check VALUE for nothing, or null, or "", or all of those.
Convert VALUE to a bool.
Attach it to a datasource instead.
Set TrueValue and FalseValue.
I've tried countless other methods, none seem to actually get the checkbox ON/OFF value in vb.net.
Cast the cell's value to a Boolean:
Dim RowIndex As Integer = ...
Dim ColumnIndex As Integer = ...
Dim IsTicked As Boolean = CBool(DataGridView1.Rows(RowIndex).Cells(ColumnIndex).Value)
If IsTicked Then
MessageBox.Show("You ticked the box.")
Else
MessageBox.Show("You cleared the box.")
End If