Looking for better solution - vb.net

I have the following code.
Surely there must be a better way of coding this using a for/next or something, but I just don't get it to work
If CheckBox1.CheckState Then bin(1) = "1" Else bin(1) = "0"
If CheckBox2.CheckState Then bin(2) = "1" Else bin(2) = "0"
If CheckBox3.CheckState Then bin(3) = "1" Else bin(3) = "0"
..
..
..
If CheckBox20.CheckState Then bin(20) = "1" Else bin(20) = "0"

OK, This should work, but bear in mind, it assumes that you have 20 CheckBoxes and that number will never change, and that the bin array will also never change the number of elements.
Private Sub SyncCheckBoxestoBinValue()
For i As Integer = 1 To 20
bin(i) = Math.Abs(CInt(CType(Me.Controls("CheckBox" & i), CheckBox).Checked)).ToString
Next
End Sub
An explanation might be in order here. Working from the inside out, here goes..
Me.Controls("CheckBox" & i)
This will refer to the control that matches CheckBox1 when i=1, CheckBox2 when i=2 etc. However, because that bit of code is designed to work with all kinds of control, it can only return it as an Object type rather than the specific type of control you're searching for.
To be able to do anything significant with that result, we need to tell the compiler that it's a CheckBox. So now we need to wrap that last bit of code in to this.
CType(Me.Controls("CheckBox" & i), CheckBox)
Now we have something that the compiler recognises as a CheckBox, we can work with it. So you want to find out of the CheckBox is checked or not. You've usedCheckstate, but personally I think it's a bit easier to useChecked` for this purpose. So ...
CType(Me.Controls("CheckBox" & i), CheckBox).Checked
This returns a result of True or False. In VB.Net this can also be seen as -1 (true) or 0 (false). although you want a 1 or 0 so that you can assign this value to your bin array. How we do this is as below
Math.Abs(CInt(CType(Me.Controls("CheckBox" & i), CheckBox).Checked)).ToString
Finally, your result of 1 or 0 is assigned to the element of bin that corresponds to the CheckBox number
That "should" do it.

Maybe make the check boxes a list and query the result by linq? For the sake of using linq for everything better readability, I mean.
Dim cbList = New List(Of CheckBox) From {checkBox1, checkBox2, checkBox3}
Dim binTmp As List(Of String) = cbList.Select(Function(chk) If(chk.checkState, "1", "0")).ToList()
bin = binTmp
You may also want to store the result as Boolean instead of "1","0" for further processing.

Related

Capturing value in DG cell

I have a DataGridView bound to a DataTable. How can I detect when a user enters a value into a cell, then populate a value into another cell?
If dataGridView3.CurrentRow.IsNewRow = True then
If Len(dataGridView3.SelectedRows(0).Cells(3)) = 7 Then
dataGridView3.SelectedRows(0).Cells(4).Value = "Surprise"
End If
End If
This code does not throw any errors but when the length is equal to 7, nothing happens in cell 4 (technically cell 5).
Cells(3) is a DataGridViewCell, but Cells(3).Value is a String (I presume). You're checking the length of the wrong object.
If Len(dataGridView3.CurrentRow.Cells(3).Value) = 7 Then
Also, Len() is an old function from the VB6 era. I highly recommed switching to the String.Length property instead:
Dim CellValue As Object = dataGridView3.CurrentRow.Cells(3).Value
If CellValue IsNot Nothing AndAlso _
CellValue.GetType() Is GetType(String) AndAlso _
DirectCast(CellValue, String).Length = 7 Then
A bit more messy solution perhaps, but the additional checks ensure that no exceptions are thrown by the If statement.

How can i check for a character after certain text within a listbox?

How can i check for a character after other text within a listbox?
e.g
Listbox contents:
Key1: V
Key2: F
Key3: S
Key4: H
How do I find what comes after Key1-4:?
Key1-4 will always be the same however what comes after that will be user defined.
I figured out how to save checkboxes as theres only 2 values to choose from, although user defined textboxes is what im struggling with. (I have searched for solutions but none seemed to work for me)
Usage:
Form1_Load
If ListBox1.Items.Contains("Key1: " & UsersKey) Then
TextBox1.Text = UsersKey
End If
Which textbox1.text would then contain V / whatever the user defined.
I did try something that kind of worked:
Form1_Load
Dim UsersKey as string = "V"
If ListBox1.Items.Contains("Key1: " & UsersKey) Then
TextBox1.Text = UsersKey
End If
but i'm not sure how to add additional letters / numbers to "V", then output that specific number/letter to the textbox. (I have special characters blocked)
Reasoning I need this is because I have created a custom save settings which saves on exit and loads with form1 as the built in save settings doesn't have much customization.
e.g Can't choose save path, when filename is changed a new user.config is generated along with old settings lost.
Look at regular expressions for this.
Using the keys from your sample:
Dim keys As String = "VFSH"
Dim exp As New RegEx("Key[1-4]: ([" & keys& "])")
For Each item As String in ListBox1.Items
Dim result = exp.Match(item)
If result.Success Then
TextBox1.Text = result.Groups(1).Value
End If
Next
It's not clear to me how your ListBoxes work. If you might find, for example, "Key 2:" inside ListBox1 that you need to ignore, you will want to change the [1-4] part of the expression to be more specific.
Additionally, if you're just trying to exclude unicode or punctuation, you could also go with ranges:
Dim keys As String = "A-Za-z0-9"
If you are supporting a broader set of characters, there are some you must be careful with: ], \, ^, and - can all have special meanings inside of a regular expression character class.
You have multiple keys, I assume you have multiple textboxes to display the results?
Then something like this would work. Loop thru the total number of keys, inside that you loop thru the alphabet. When you find a match, output to the correct textbox:
Dim UsersKey As String
For i As Integer = 1 To 4
For Each c In "ABCDEFGHIJKLMNOPQRSTUVWXYZ".ToCharArray()
UsersKey = c
If ListBox1.Items.Contains("Key" & i & ": " & UsersKey) Then
Select Case i
Case 1
TextBox1.Text = UsersKey
Case 2
TextBox2.Text = UsersKey
Case 3
TextBox3.Text = UsersKey
Case 4
TextBox4.Text = UsersKey
End Select
Exit For 'match found so exit inner loop
End If
Next
Next
Also, you say your settings are lost when the filename is changed. I assume when the version changes? The Settings has an upgrade method to read from a previous version. If you add an UpgradeSettings boolean option and set it to True and then do this at the start of your app, it will load the settings from a previous version:
If My.Settings.UpgradeSettings = True Then
My.Settings.Upgrade()
My.Settings.Reload()
My.Settings.UpgradeSettings = False
My.Settings.Save()
End If
Updated Answer:
Instead of using a listtbox, read the settings file line by line and output the results to the correct textbox based on the key...something like this:
Dim settingsFile As String = "C:\settings.txt"
If IO.File.Exists(settingsFile) Then
For Each line As String In IO.File.ReadLines(settingsFile)
Dim params() As String = Split(line, ":")
If params.Length = 2 Then
params(0) = params(0).Trim
params(1) = params(1).Trim
Select Case params(0)
Case "Key1"
Textbox1.Text = params(1)
Case "Key2"
Textbox2.Text = params(1)
End Select
End If
Next line
End If
You can associate text box with a key via its Name or Tag property. Lets say you use Name. In this case TextBox2 is associated with key2. TextBox[N] <-> Key[N]
Using this principle the code will look like this [considering that your list item is string]
Sub Test()
If ListBox1.SelectedIndex = -1 Then Return
Dim data[] As String = DirectCast(ListBox1.SelectedItem, string).Split(new char(){":"})
Dim key As String = data(0).Substring(3)
Dim val As String = data(1).Trim()
' you can use one of the known techniques to get control on which your texbox sits.
' I omit this step and assume "Surface1" being a control on which your text boxes sit
DirectCast(
(From ctrl In Surface1.Controls
Where ctrl.Name = "TextBox" & key
Select ctrl).First()), TextBox).Text = val
End Sub
As you can see, using principle I just explained, you have little parsing and what is important, there is no growing Select case if, lets say, you get 20 text boxes. You can add as many text boxes and as many corresponding list items as you wish, the code need not change.

Control name from Variable or Dataset. (Combobox)(.items.add)(.datasource)

I've checked for hours but I can't seem to find anything to help.
I want to loop through tables and columns from a dataset and use the column name in a combobox.items.add() line, however the eventual goal is to fill the combobox from the dataset itself possibly in a combobox.datasource line.
The first problem is that I can't get the code correct to setup the combobox control where it allows me to use .items.add("") and in extension .datasource
Error Message = "Object reference not set to an instance of an object"
dstcopt is the dataset from a oledbDataAdapter .fill(dstcopt,"table") line (which returns correct values)
tc_opt is a tab name on a tab control where the comboboxes are
For Each dstable In dstcopt.Tables
For Each dscolumn In dstable.Columns
Dim colName As String = dscolumn.ToString
MsgBox(colName) 'This retuns "aantigen"
Dim cb As ComboBox = Me.tc_opt.Controls("cb_" & colName)
cb.Items.Add(colName)
'cb_aantigen.DataSource = dstcopt.Tables(dstable.ToString)
'cb_aantigen.DisplayMember = "aantigen"
'cb_atarget.DataSource = dstcopt.Tables(dstable.ToString)
'cb_atarget.DisplayMember = "atarget"
Next
Next
The second problem comes when I do it manually (which works) using the exact combobox names cb_aantigen and cb_atarget as seen in the comments.
The problem is that once the form is loaded and the cb's are filled with the correct values, I can't change the value in any single cb individually, when I change one value it changes them all (there is 15 comboboxes in total) I know this is down to using a dataset, but I don't know away to 'unlink them from each other or the dataset'
Not sure if I need to split this into 2 questions, but help on either problem would be appreciated.
EDIT:
After looking at only this section of code for a day. This is what I have come up with to tackle both the problems at once.
The combobox control not working was down to using a tab tc_opt instead of a groupbox gp_anti
The issue with splitting the dataset up into individual comboboxes, I've worked around by taking the value of each cell in the database and adding it separately, probably a better way to do it though
For Each dstable As DataTable In dstcopt.Tables
For Each dscolumn As DataColumn In dstable.Columns
Dim colName As String = dscolumn.ToString
Dim cb(2) As ComboBox
cb(0) = CType(Me.gp_anti.Controls("cb_" & colName), ComboBox)
cb(1) = CType(Me.gp_rec.Controls("cb_" & colName), ComboBox)
cb(2) = CType(Me.gp_nat.Controls("cb_" & colName), ComboBox)
For icb = 0 To cb.Count - 1
If Not (IsNothing(cb(icb))) Then
For irow = 0 To dstable.Rows.Count - 1
If dstable.Rows(irow)(colName).ToString <> Nothing Then
Dim icbitemdupe As Boolean = False
If cb(icb).Items.Contains(dstable.Rows(irow)(colName).ToString) Then
icbitemdupe = True
End If
If icbitemdupe = False Then
cb(icb).Items.Add(dstable.Rows(irow)(colName).ToString)
End If
End If
Next
End If
Next
Next
Next

String.compare returns true when strings aren't equal?

I've seen plenty of questions here about strings that are equal returning as unequal, but trust me to not get that problem.
I have this function.
Protected Sub ChkValidStockCode()
If Not (Voucher.ValidStockCode = "") Then
Dim validcount As Int32 = 0
Dim validproduct As String = Product.GetProductNameByCode(Voucher.ValidStockCode)
For Each rpi As RepeaterItem In rptCart.Items
Dim ProductID As HyperLink = CType(rpi.FindControl("hlProductID"), HyperLink)
Dim ProductName As HyperLink = CType(rpi.FindControl("hlProductName"), HyperLink)
If (String.Compare(Voucher.ValidStockCode.ToString(), ProductID.ToString())) Then
validcount = validcount + 1
End If
Next
If validcount = 0 Then
txtVoucher.Text = "Sorry, this voucher is only valid when purchasing a " & validproduct
failed = True
Exit Sub
End If
End If
End Sub
It's supposed to compare the two strings and increment a validcount integer if they're equal, and then tell you off if it gets to the end of the repeater without finding any matches.
The variables in this test are LT00004 (Voucher.ValidStockCode) and SP08076 (ProductID.ToString())
I have run the code several times, outputting the different strings as the result and can confirm they are what they should be, but when I try to compare them (and I expect validCount to be 0), they return as a match.
What did I do to screw this up?
You probably want String.Equals() and not String.Compare(). Compare is used to order things and not test for equality. What's happening is String.Compare is returning a non-zero number so the condition is being satisfied. The reason for that is because in VB "0" is False but any non-zero number evaluates to true. There's a whole history behind why that's the case but I digress.

Keeping a count in a dictionary, bad result when running the code, good result adding inspections

Weird problem. Stepping through the code with inspections gives me correct answers. Just running it doesn't.
This program loops through each cell in a column, searching for a regex match. When it finds something, checks in a adjacent column to which group it belongs and keeps a count in a dictonary. Ex: Group3:7, Group5: 2, Group3:8
Just stepping through the code gives me incorrect results at the end, but adding and inspection for each known item in the dictionary does the trick. Using Debug.Print for each Dictionary(key) to check how many items I got in each loop also gives me a good output.
Correct // What really hapens after running the code
Group1:23 // Group1:23
Group3:21 // Group3:22
Group6:2 // Group6:2
Group7:3 // Group7:6
Group9:8 // Group9:8
Group11:1 // Group11:12
Group12:2 // Group12:21
Sub Proce()
Dim regEx As New VBScript_RegExp_55.RegExp
Dim matches
Dim Rango, RangoJulio, RangoAgosto As String
Dim DictContador As New Scripting.Dictionary
Dim j As Integer
Dim conteo As Integer
Dim Especialidad As String
regEx.Pattern = "cop|col"
regEx.Global = False 'True matches all occurances, False matches the first occurance
regEx.IgnoreCase = True
i = 3
conteo = 1
RangoJulio = "L3:L283"
RangoAgosto = "L3:L315"
Julio = Excel.ActiveWorkbook.Sheets("Julio")
Rango = RangoJulio
Julio.Activate
For Each celda In Julio.Range(Rango)
If regEx.Test(celda.Value) Then
Set matches = regEx.Execute(celda.Value)
For Each Match In matches
j = 13 'column M
Especialidad = Julio.Cells(i, j).Value
If (Not DictContador.Exists(Especialidad)) Then
Call DictContador.Add(Especialidad, conteo)
GoTo ContinueLoop
End If
conteo = DictContador(Especialidad)
conteo = CInt(conteo) + 1
DictContador(Especialidad) = conteo
Next
End If
ContinueLoop:
i = i + 1
'Debug.Print DictContador(key1)
'Debug.Print DictContador(key2)
'etc
Next
'Finally, write the results in another sheet.
End Sub
It's like VBA saying "I'm going to dupe you if I got a chance"
Thanks
Seems like your main loop can be reduced to this:
For Each celda In Julio.Range(Rango)
If regEx.Test(celda.Value) Then
Especialidad = celda.EntireRow.Cells(13).Value
'make sure the key exists: set initial count=0
If (Not DictContador.Exists(Especialidad)) Then _
DictContador.Add Especialidad, 0
'increment the count
DictContador(Especialidad) = DictContador(Especialidad) +1
End If
Next
You're getting different results stepping through the code because there's a bug/feature with dictionaries that if you inspect items using the watch or immediate window the items will be created if they don't already exist.
To see this put a break point at the first line under the variable declarations, press F5 to run to the break point, then in the immediate window type set DictContador = new Dictionary so the dictionary is initialised empty and add a watch for DictContador("a"). You will see "a" added as an item in the locals window.
Collections offer an alternative method that don't have this issue, they also show values rather than keys which may be more useful for debugging. On the other hand an Exists method is lacking so you would either need to add on error resume next and test for errors instead or add a custom collection class with an exists method added. There are trade-offs with both approaches.