I have auto complete functionality in combo box ,it works properly but there is little issue ,I made the suggestion list appear for the text length more than 3 chars ,but the list appears after the length of 4 char (when user enters the fifth char of the text) which means when the code executed in the first time the list doesn't appear here is the code in Text_Changed Event
Private Sub TxtItem_TextChanged(sender As System.Object, e As System.EventArgs) Handles TxtItem.TextChanged
If Trim(TxtItem.Text) <> "" And Trim(TxtItem.Text).Length > 3 Then
'Autocomplete
Dim Bl As New ItemBL
Dim suggestions = Bl.DisplayLikeNameList(Trim(TxtItem.Text))
Dim MySource As New AutoCompleteStringCollection()
MySource.AddRange(suggestions.ToArray)
With TxtItem
.AutoCompleteMode = AutoCompleteMode.Suggest
.AutoCompleteSource = AutoCompleteSource.CustomSource
.AutoCompleteCustomSource = MySource
End With
TxtItem.Select(TxtItem.Text.Length, 0)
Exit Sub
Else
TxtItem.AutoCompleteMode = AutoCompleteMode.None
End If
End Sub
Note : This issue causes the application exit (sometimes) on Windows XP, but Doesn't affect on Windows 7
The answer was found in this post: Dynamically changing Textbox's AutoComplete List causes AccessViolationException, any advice?
So I had to make global list of suggestions and initialize the AutoComplete property in the Form load event and it worked good .
Related
What i need to do is take input 10 times from a text box, store it in an array and then display the array onto a list box.
I came up with this for loop but it doesn't work, all it does is display the first input and then the rest are just blank:
For i As Integer = 0 To 9
ArrNames(i) = txtUserInput.Text
txtUserInput.Clear()
Next i
and i have a different button to display the array and i used this:
lstDisplay.DataSource = ArrNames
can anyone help me? iv'e looked everywhere and nothing worked for me
Edit 1:
So i changed it a lot and came up with this:
Dim I As Integer
If sender Is btnEnter Then
I = I + 1
End If
ArrNames(I) = txtUserInput.Text
txtUserInput.Clear()
is what it does is if the button is pressed it increases I by one which makes it so the input goes to the right index right?
but now that i make this it stopped displaying anything at all so this:
Private Sub btnShow_Click(sender As Object, e As EventArgs) Handles btnShow.Click
lstDisplay.DataSource = ArrNames
stopped working
Hopefully that I variable is declared at class level in the same place as the array.
To force the ListBox to refresh you have to set the .DataSource to Nothing and then back to your array again:
Public Class Form1
Private I As Integer
Private ArrNames(9) As String
Private Sub btnAddName_Click(sender As Object, e As EventArgs) Handles btnAddName.Click
If I < ArrNames.Length Then
If txtUserInput.Text.Trim.Length > 0 Then
ArrNames(I) = txtUserInput.Text
I = I + 1
lstDisplay.DataSource = Nothing
lstDisplay.DataSource = ArrNames
txtUserInput.Clear()
txtUserInput.Focus()
Else
MessageBox.Show("Enter a name first!")
End If
Else
MessageBox.Show("The array is full!")
End If
End Sub
End Class
I would first recommend you to use typed Lists instead of using the old fashioned array (discussions incoming.. but..).
You can also make use of the nice feature of Enumerable.Range().
I don't have my editor right now but it should look like:
Dim list = new List(Of string)
For i In Enumerable.Range(1, 10)
list.Add(txtUserInput.Text)
Next
txtUserInput.Clear()
lstDisplay.DataSource = list
If you plan to modify your list afterwards and e.g. keep it on class scope, then you should use a BindingList(Of String) which supports notifying about changes.
Edit 1:
You are calling txtUserInput.Clear() inside the loop after the first time your input has been received from the textbox. That means in each following iteration the textbox is cleared.
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
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 a small program that on "Load" button click creates object info and populates a text field. I also have a clear button that resets everything on the form. On form load if you click the "load" button without first choosing a company from the drop down list you get an error saying "choose company first".
If you choose a company and hit "load" everything works perfectly. If you hit clear everything clears out but if you then hit "load" it fills the text field with the info from the previously chosen company instead of showing the "choose company first error".
does anyone out there have any suggestions that might help to truly clear everything when the clear button is clicked?
here is my code
Public Sub btn_LoadScript_Click(sender As Object, e As EventArgs) Handles btn_LoadScript.Click
'get vb script
If cb_COID.SelectedItem = String.Empty Then
lbl_FormMainUserMessage.Text = "Select a Company Code"
Else
Try
Dim co As Object = M3System.GetEntity("MillCompany.Company", cb_COID.SelectedItem)
Dim script As Object = co.Scripting.ItemByKey("PaycheckCalc")
'Dim script = co.Scripting.ItemByKey("CCalcCode")
Scintillatb_Script.Text = script.vbscript
Catch ex As Exception
lbl_FormMainUserMessage.Text = ex.Message
End Try
End If
End Sub
Private Sub btn_Reset_Click(sender As Object, e As EventArgs) Handles btn_Reset.Click
'clear form
For Each cb In Me.Controls.OfType(Of ComboBox)()
cb.Text = String.Empty
cb.SelectedItem = String.Empty
Next cb
For Each tb In Me.Controls.OfType(Of TextBox)()
tb.Text = String.Empty
Next tb
For Each lb In Me.Controls.OfType(Of Label)()
lb.Text = String.Empty
Next lb
Scintillatb_Script.Text = ""
End Sub
Try to set your dropdown selected index -1.
Add to your clear code :
YourDropdown.selectedindex = -1
How are you clearing the drop down list? it seems that the text of the drop down list is cleared, but not the selected index or selected item of that drop down list.
That's why when clicking load for the second time after clearing the UI, it still loads the information, instead of mentioning the error message "Choose company first error"