getting System.InvalidOperationException: Listbox DataSource VB.net - vb.net

This is the error I am getting
System.InvalidOperationException: 'List that this enumerator is bound to has been modified. An enumerator can only be used if the list does not change.'
I have a Listbox that is databound The list of items are stored days table the saved value is stored in a record table. The List is a Comma Separated List E.G: 1,2,3,4,5
Would equate to Items with values of 1 -5 being selected on load.
This is the save Routine which Works perfectly
Private Sub ListBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ListBox1.Leave
Dim listboxItems As New List(Of String)
For Each row As DataRowView In ListBox1.SelectedItems
listboxItems.Add(row("IDNum"))
Next row
selectLoad = True
lblDays.Text = String.Join(",", listboxItems.ToArray())
End Sub
This is Routine Which is Throwing the error.
Private Sub BGWLoadData_RunWorkerCompleted(sender As Object, e As System.ComponentModel.RunWorkerCompletedEventArgs) Handles BGWLoadData.RunWorkerCompleted
Dim TextBoxStrings() As String = {""}
Try
Dim TempStr() As String = lblDays.Text.Split(",")
ReDim TextBoxStrings(TempStr.Count - 1)
TextBoxStrings = TempStr
Catch ex As Exception
End Try
Dim TextBoxDoubles(TextBoxStrings.Count - 1) As Double
For a As Integer = 0 To TextBoxStrings.Count - 1
Try
TextBoxDoubles(a) = TextBoxStrings(a)
Catch ex As Exception
TextBoxDoubles(a) = 0
End Try
Next
Do While DaysBound = False
Application.DoEvents()
Loop
ListBox1.SelectedItems.Clear()
Dim TempIndex As Integer = 0
For Each row As DataRowView In ListBox1.Items
For a As Integer = 0 To TextBoxDoubles.Count - 1
If row("IDNum") = TextBoxDoubles(a) Then
ListBox1.SetSelected(TempIndex, True)
End If
Next
TempIndex = TempIndex + 1
Next row
End Sub
What am I doing wrong or what can be done to make the code more efficient.
Edit:
Error Occurs at Next Row.
Also telling me I have done something wrong isn't helpful I know something is Wrong because I am getting errors. I am asking for is how to fix this with a code snippet or something.

This Has been Solved by Adding a second arrary
If selectLoad = False Then
' convert CSV of IDNums of selected items in listbox into string array
Dim TextBoxStrings() As String = {""}
Try
Dim TempStr() As String = lblDays.Text.Split(",")
ReDim TextBoxStrings(TempStr.Count - 1)
TextBoxStrings = TempStr
Catch ex As Exception
End Try
' convert string array to double array
Dim TextBoxDoubles(TextBoxStrings.Count - 1) As Double
For a As Integer = 0 To TextBoxStrings.Count - 1
Try
TextBoxDoubles(a) = TextBoxStrings(a)
Catch ex As Exception
TextBoxDoubles(a) = -1
End Try
Next
' load underlying IDNums into temporary array
Dim TempIndex As Integer = 0
Dim TempIDNums(ListBox1.Items.Count - 1) As Integer
For Each row As DataRowView In ListBox1.Items
TempIDNums(TempIndex) = row("IDNum")
TempIndex = TempIndex + 1
Next row
' if any of the underlying IDNums are found in the CSV, select that item in the listbox
ListBox1.SelectedItems.Clear()
For ListItemCounter As Integer = 0 To TempIDNums.Count - 1
For SelectedItemCounter As Integer = 0 To TextBoxDoubles.Count - 1
If TempIDNums(ListItemCounter) = TextBoxDoubles(SelectedItemCounter) Then
ListBox1.SetSelected(ListItemCounter, True)
End If
Next
Next
End If

Related

prevent go to next row when duplicated value in `datagridview`

I have datagrid that user will add values in just one column , and i want to prevent duplicated data in this column, i had mange that by the code bellow,
what I want is to keep the selection (focus) in the same editing cell(x)
if the entered data is duplicated, so I tried to get the current row index and return to it if the data is duplicated but its not working.
row_index = DataGridView1.CurrentRow.Index.ToString()
Dim cell As DataGridViewCell = DataGridView1.Rows(row_index).Cells(1)
DataGridView1.CurrentCell = cell
DataGridView1.BeginEdit(True)
NOTE : User will Add barcode number, so he will use barcode scanner or add it manually and press enter key.
Private Sub DataGridView1_RowValidated(sender As Object, e As DataGridViewCellEventArgs) Handles DataGridView1.RowValidated
If DataGridView1.Rows.Count > 2 Then
Dim i As Integer = 0
Dim row_index As Integer
' loop condition will loop while the row count is less or equal to i
While i <= DataGridView1.Rows.Count - 1
Dim j As Integer = 1
' loop condition will loop while the row count is less or equal to j
While j <= DataGridView1.Rows.Count - 1
Dim str As String = DataGridView1.Rows(i).Cells(1).Value()
Dim str1 As String = DataGridView1.Rows(j).Cells(1).Value()
If Not str1 = "" AndAlso Not str = "" Then
If str1 = str Then
'row_index = DataGridView1.SelectedCells.Item(i).RowIndex.ToString()
row_index = DataGridView1.CurrentRow.Index.ToString()
Dim cell As DataGridViewCell = DataGridView1.Rows(row_index).Cells(1)
DataGridView1.CurrentCell = cell
DataGridView1.BeginEdit(True)
Exit Sub
End If
End If
j += 1
End While
i += 1
End While
End If
End Sub
You can try it also in a for loop. This is how I do it. If what you mean is to stop/retain the selection(focus) or go to in a cell/row whenever it is a duplicate with the current data you have. This should work fine.
enter code here
For i = 0 To Datagridview1.Rows.Count - 1
If Datagridview1.Rows(i).Cells(1).Value = DataYouWillInput Then
DataGridView1.CurrentCell = DataGridView1.Rows(i).Cells(1)
Exit for
End If
Next
enter code here
If your condition returns true with the condition of current data and data you'll be adding. Just exit your loop. Use this.
DataGridView1.CurrentCell = DataGridView1.Rows(i).Cells(1)

How to check if Variable value is increaseing vb.net?

Hi I have listview and lable ,the lable is showing how many items in the listview
I want if the lable is increased will show msgbox
* may be it will increased alot such as 100 or 1 whatever
* It will execute the command just one if the value is increased
* it must be execute the msgbox any time if the value is increased
I'm sorry for my bad language
thank you
the code :
Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
Dim b As String = New WebClient().DownloadString(TextBox2.Text + "/Getinfo.php")
Dim mc As MatchCollection = Regex.Matches(b, "(\w+):")
For Each x As Match In mc
Dim infoName As String = x.Groups(1).Value
Try
Dim download As String = New WebClient().DownloadString(TextBox2.Text + "/sender/info/" & infoName & "/info.txt")
Dim f As String() = download.Split(":")
Dim ls As New ListViewItem
ls.Text = infoName
For Each _x As String In f
ls.SubItems.Add(_x)
Next
Dim hTable As Hashtable = New Hashtable()
Dim duplicateList As ArrayList = New ArrayList()
Dim itm As ListViewItem
For Each itm In ListView1.Items
If hTable.ContainsKey(itm.Text) Then 'duplicate
duplicateList.Add(itm)
Else
hTable.Add(itm.Text, String.Empty)
End If
Next
'remove duplicates
For Each itm In duplicateList
itm.Remove()
Next
ListView1.Items.Add(ls)
'here I want to excute the command if the value is increased but it's timer and the code will be execute every time
Catch
End Try
Next
End Sub
At the top of your function do
Dim oldlength = ListView1.Items.Count
At the bottom do
If oldlength < ListView1.Items.Count Then
'here I want to excute the command if the value is increased
End If
I'm pretty sure that your MessageBox isn't really what you want but a debugging example because you think if you can get the MessageBox at the right time you've solved one of your problems (which is true).

Highlight specific text while user is typing

I am writing a code that highlight the duplicate words in a text. The code is working well when I add a button and the user have to press on the button to check for duplicates.
But I want to make an auto-checking code. I set my code in a subroutine that Handles RichTextBox.TextChanged. The problem is the code selects the target word and highlight it but the selection remains so when a new letter is typed, it clear what has been highlighted.
Here is my code:
Private Sub RichTextBox_TextChanged(sender As Object, e As EventArgs) Handles RichTextBox.TextChanged
Try
Call duplicate_check()
Catch ex As Exception
MessageBox.Show("error in RichTextBox.TextChanged")
End Try
End Sub
duplicate check function:
Private Sub duplicate_check()
Try
' read line by line and get input
Dim LineByLineInput() As String = RichTextBox.Lines
Dim selectionStart, selectionLength As Integer
Dim i, j As Integer
For lineNumber = 0 To UBound(LineByLineInput)
selectionStart = 0
selectionLength = 0
'get index of first char index in the current line
Dim count As Integer = lineNumber
While count <> 0
selectionStart += RichTextBox.Lines(count - 1).Length + 1
count -= 1
End While
' get line as string
Dim line As String = RichTextBox.Lines(lineNumber)
' split line into array of strings
Dim input() As String = line.Split(" ")
'check for duplicates
i = 0
For j = i + 1 To UBound(input)
If input(i) = input(j) Then 'compare each 2 consecutive words if they are the same
selectionStart += input(i).Length + 1
selectionLength = input(i).Length
RichTextBox.SelectionStart = selectionStart
RichTextBox.SelectionLength = selectionLength
RichTextBox.SelectionBackColor = Color.Yellow
Else
selectionStart += input(i).Length + 1
End If
i += 1
Next
Next
Catch ex As Exception
MessageBox.Show("error duplicate_check()")
End Try
End Sub
After your duplicate_check call, have you tried to set the selection of the RichTextBox back to the old position ?
See below :
Private Sub RichTextBox1_TextChanged(sender As Object, e As System.EventArgs) Handles RichTextBox1.TextChanged
Try
' Get current position
Dim cur_pos As Integer = Me.RichTextBox.SelectionStart
Call duplicate_check()
' Set back to old position
Me.RichTextBox.SelectionStart = cur_pos
' Unselect what your sub duplicate_check has selected
Me.RichTextBox1.SelectionLength = 0
Catch ex As Exception
MessageBox.Show("error in RichTextBox.TextChanged")
End Try
End Sub
If this solution is good for you, you should change your duplicate_check Sub to make this change and not in the RichTextBox1_TextChanged Sub

how to check checklistbox items using datagridview vb.net?

I'm just a beginner for coding and I want to programmatically check items in checklistbox using datagridview.
Data grid view values are seperated with commas like this jhon,Metilda,saman,.
Checklistbox name as chklistinput and please help me to solve this ?
'Full coding is here..............................
Private Sub TextBox10_TextChanged(sender As Object, e As EventArgs) Handles TextBox10.TextChanged
'this is ok and searching as I want
Dim SearchV As String = TextBox10.Text
SearchV = "%" + TextBox10.Text + "%"
Me.PassIssuingRecordTableAdapter.FillBy(Me.Database4DataSet.PassIssuingRecord, SearchV)
'But the problem bigins here
Dim areasback As String = DataGridView1.Rows(0).Cells(6).Value.ToString
Dim areasback1 As String() = areasback.Split(",")
For Each x In areasback1
For i = 0 To areasback.Count - 1
If chklistInput.Items(i).ToString() = x.ToString() Then
chklistInput.SetItemChecked(i, False)
End If
Next
Next
End Sub
You have to loop over chklistInput.Items.Count - 1 instead of areasback.Count - 1
use the following code:
Dim areasback As String = DataGridView1.Rows(0).Cells(6).Value.ToString
Dim areasback1 As String() = areasback.Split(",")
Dim intCount as integer = 0
For each str as string in areasback1
For intCount = 0 To chklistInput.Items.Count - 1
If chklistInput.Items(intCount).ToString() = str Then
chklistInput.SetItemChecked(intCount , True)
End If
Next
Next
chklistInput.Refresh()
Note: comparing is case sensitive

Index out-of-range error

I am getting an error when I execute this button event: here is my code:
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
Handles Button1.Click
Try
' get the details of the item
Dim R As Your_pharmacy.POSDS.ItemsRow = Button1.Tag
' next search for the barcode in the datagridview
Dim I As Integer
Dim ItemLoc As Integer = -1
For I = 0 To DGV1.Rows.Count - 1
If R.barcodeNumber = DGV1.Rows(I).Cells(0).Value Then
' item found
ItemLoc = I
Exit For
End If
Next
' if item is not found, add it
If ItemLoc = -1 Then
DGV1.Rows.Add(R.barcodeNumber, R.ItemName, R.BuyPrice, R.SellPrice, 1, R.SellPrice)
Else
' if item is already there increase its count
Dim ItemCount As Long = DGV1.Rows(ItemLoc).Cells(4).Value
ItemCount += 1
Dim NewPrice As Decimal = R.SellPrice * ItemCount
DGV1.Rows(ItemLoc).Cells(4).Value = ItemCount
DGV1.Rows(ItemLoc).Cells(5).Value = NewPrice
End If
' next clear textbox1 and set focus to it
TextBox1.Text = ""
TextBox1.Focus()
' compute the total for the recipt
Dim Sum As Decimal = 1
For I = 0 To DGV1.Rows.Count - 1
Sum += DGV1.Rows(I).Cells(5).Value 'here the error happens
Next
TextBox4.Text = Sum
Catch ex As Exception
MsgBox(ex.Message, MsgBoxStyle.Critical Or MsgBoxStyle.OkOnly, "Error")
End Try
End Sub
The error details:
error: index was out of range.must be non-negative and less than the
size of the collection. parameter name: index vb.net
DGV1 must have fewer cells than 5. When the error occurs, use a breakpoint and the debug watch window to see how many cells there are in DVG1(I). Maybe the first one is created with zero cells?