VB.NET Array/Hashtable Issue - vb.net

I am trying to make an array of hashtables. I don't know if this is the best solution, in PHP I would just do a multi-dim array, but it's not so easy in .NET. I am pretty new o VB, so if there is a better solution for this please explain.
I have 2 emails fields for a contact, and a contact can have many. I just want to load in the first two on the edit page for editing, whatever they may be.
Private Sub loadPrimaryContactEmails(ByVal db As CRMDataDataContext, ByVal contactID As Guid)
Dim q = (From ce In db.ContactEmails Where ce.ContactID = contactID Select ce).Take(2)
Dim Emails As Array
Dim count = 0
For Each email In q
Emails(count) = New Hashtable
Emails(count).Add("email", email.Email)
Emails(count).Add("label", email.Label)
Emails(count).Add("id", email.ContactEmailID)
count = count + 1
Next
txtPCEmail1.Text = Emails(0).Item("email")
txtPCEmail1Label.Text = Emails(0).Item("label")
lblEmail1ID.Text = Emails(0).Item("id")
txtPCEmail2.Text = Emails(1).Item("email")
txtPCEmail2Label.Text = Emails(1).Item("label")
lblEmail2ID.Text = Emails(1).Item("id")
End Sub
I get the error the first time I try to reference my array:
txtPCEmail1.Text = Emails(0).Item("email")
The error is:
Object variable or With block variable not set.
It builds, so I thought it might work. I can't just loop through my datasource because I have to explicitly set textbox fields. Is there a better way to go about doing this? Or is there a way to make an array of hashtables work?
EDIT - here is the good code:
So I went w/ the HybridDictionary...
Private Sub loadPrimaryContactEmails(ByVal db As CRMDataDataContext, ByVal contactID As Guid)
Dim q = (From ce In db.ContactEmails Where ce.ContactID = contactID Select ce).Take(2)
Dim Emails As New HybridDictionary()
Dim count = 1
For Each email In q
Emails.Add("email" + NCStr(count), email.Email)
Emails.Add("label" + NCStr(count), email.Label)
Emails.Add("id" + NCStr(count), email.ContactEmailID)
count = count + 1
Next
txtPCEmail1.Text = Emails("email1")
txtPCEmail1Label.Text = Emails("label1")
lblEmail1ID.Text = Emails("id1")
txtPCEmail2.Text = Emails("email2")
txtPCEmail2Label.Text = Emails("label2")
lblEmail2ID.Text = Emails("id2")
End Sub
SO yeah, kind of a hack, but I don't feel like I should have to making special methods just to load some data into a dictionary or array or whatever.

Arrays in VB.NET are different than in PHP. You will need to define the size of your array before attempting to set elements of the array.
Better yet, consider using the generic List<T> collection.

Yes Phil is right you haven't specified the Initial Size of the Array.
And as suggested by him Use generic list or I would recommend
"System.Collections.Specialized.StringCollection" Class or "System.Collections.Specialized.HybridDictionary" class

Build the hashtable first and then build the array.
Dim hash As New Hashtable()
hash.Add("Header", shortModel)
hash.Add("SpecInfo", specinfo)
hash.Add("SerialNumber", serie & "-L")
hash.Add("SerialNumber2", serie)
hash.Add("seriel", serie & "-L")
hash.Add("serie", serie)
hash.Add("Product", modelBase)
hash.Add("varBC", bc)
hash.Add("box_id", boxId.Substring(4).ToString)
Dim dt As DataTable = DbUtil.GetCursor("SFISM4.PKG_AGENCY.sp_get_print_param", {New OracleParameter("in_serie", "3CE5151ZW4")})
For Each row As DataRow In dt.Rows
hash.Add(row("NAME"), row("VALUE"))
Next
Dim mArray(hash.Count() - 1, 1) As String
Dim i As Integer = 0
For Each row As DictionaryEntry In hash
mArray(i, 0) = row.Key.ToString()
mArray(i, 1) = row.Value.ToString()
i = i + 1
Next

Related

How to get the value of a column using a dataview in vb.net

I have a list of records and for Employee R1005, I need to check if that Employee has been Enabled for login alert (i.e EnableLoginAlert = Yes), then a button will be displayed.
CompanyID EmployeeNo EnableLoginAlert
10046 R1005 Yes
20041 Ajax12 No
47021 Drek Yes
I have tried the below codes:
If dCompanyDetails.Tables(0).Rows.Count > 0 Then
Dim dataView As DataView = dCompanyDetails.Tables(0).DefaultView
dataView.RowFilter = "EmployeeNo = '" & strEmployeeNumber & "'"
Dim svalue As String = dataView.Table.Rows(0).ItemArray(0).ToString()
If svalue = "No" Then
AlertButton.Visible = False
ElseIf svalue = "Yes" Then
{
//Do something else
}
End If
End If
If you are going to use a DataView then use it. This:
Dim svalue As String = dataView.Table.Rows(0).ItemArray(0).ToString()
is simply going back to the DataTable and using it, ignoring the DataView. The DataView contains DataRowView objects so get the one you need and use it. It is similar to a DataRow and you can use it the same way in this case:
Dim enableLoginAlert = CStr(dataView(0)("EnableLoginAlert")) = "Yes"
Now you have an actual Boolean that represents the state you want.
That's not how you should do it though. Generally speaking, you would use a DataView when you want to bind data. In fact, if you bind a DataTable then the data you see in the UI actually comes from the DefaultView. That's why you can filter and sort it. In this case, there are better options.
If you want to find a row by its primary key then the Rows collection of a DataTable has a Find method, e.g.
Dim row = dCompanyDetails.Tables(0).Rows.Find(strEmployeeNumber)
Dim enableLoginAlert = CStr(row("EnableLoginAlert")) = "Yes"
If you're searching by other than the primary key, the DataTable itself has a Select method. Because multiple rows may match, it returns an array, so you need to get the row out of that, e.g.
Dim row = dCompanyDetails.Tables(0).Select($"EmployeeNo = '{strEmployeeNumber}'").First()
Dim enableLoginAlert = CStr(row("EnableLoginAlert")) = "Yes"
If you want to look up a single row it's perhaps easiest to use LINQ:
Dim row = dCompanyDetails.Tables(0).Rows.Cast(Of DataRow).AsQueryable().FirstOrDefault(Function(r) r("EmployeeNo").ToString() = strEmployeeNumber)
If row IsNot Nothing AndAlso row("EnableLoginAlert").ToString() = "Yes" Then
...
..though I'd be the first to claim that using LINQ on base DataTables is very verbose, because of the Cast/AsQueryable. I'd use strongly typed DataTables (in a dataset); if you were to convert your code to using strongly typed tables it would look like:
Dim r = someDataSet.AProperTableName.FirstOrDefault(Function(r) r.EmployeeNo = strEmployeeNumber)
If r?.EnableLoginALert = "Yes" Then
...
...using strongly typed datatables is much less messy..
nb: You need to Imports System.Linq for these to work
That LINQ is the same thing as:
For Each r as DataRow in dCompanyDetails.Tables(0)
If r("EmployeeNo").ToString() = "R1005" AndAlso r("EnableLoginAlert").ToString() = "Yes" Then
...
You also have the option of using DataTable.Select (not a LINQ thing, though LINQ has a Select too)
Dim matchingRows = dCompanyDetails.Tables(0).Select($"[EmployeeNo] = '{strEmployeeNumber}'")
If matchingrows.Count > 0 AndAlso matchingRows(0)("EnableLoginAlert").ToString() = "Yes"

Checking Someone is a Member Of One of Many Groups Using Partial Group Name

I'm a bit stuck trying to work something into my code.
What I'm looking to do is to work out whether someone is a member of any one of a collection of groups. I'm not worried about which group specifically, I only want to know:
"Is user "X" a member of at least one of this collection of groups?"
The good news is, ALL these group names start in the same way:
Google-FullAccess
Google-RestrictedAccess
Google-MailOnly
Google-Enterprise etc.
Here's what I'm using to check for a specific group:
Dim ctx As DirectoryServices.AccountManagement.PrincipalContext = New DirectoryServices.AccountManagement.PrincipalContext(DirectoryServices.AccountManagement.ContextType.Domain, "net.mydomain.co.uk")
Dim user As DirectoryServices.AccountManagement.UserPrincipal = DirectoryServices.AccountManagement.UserPrincipal.FindByIdentity(ctx, tbxuserID.Text)
Dim googleFull As DirectoryServices.AccountManagement.GroupPrincipal = DirectoryServices.AccountManagement.GroupPrincipal.FindByIdentity(ctx, "Google-FullAccess")
If user.IsMemberOf(googleFull) Then
GoogleAccess = 1
GoTo Proceed
End If
I then repeat this block of code to check for the next group and so on.
Is there a way I can adapt this to check for any group starting with "Google-"? Here's what I'd like to do but obviously doesn't work:
Dim googleCheck As DirectoryServices.AccountManagement.GroupPrincipal = DirectoryServices.AccountManagement.GroupPrincipal.FindByIdentity(ctx, "Google-*")
Help much appreciated!
I found the solution! The following works for me (after working out and storing the DistinguishedName in a String variable from a previous query - I also declare GoogleCheck as a Boolean variable beforehand):
Dim rootEntry As DirectoryServices.DirectoryEntry = New DirectoryServices.DirectoryEntry("LDAP://DC=net,DC=mydomain,DC=co,DC=uk")
Dim srch As DirectoryServices.DirectorySearcher = New DirectoryServices.DirectorySearcher(rootEntry)
srch.SearchScope = DirectoryServices.SearchScope.Subtree
srch.Filter = "(&(CN=Google-*)(objectCategory=group)(member=" + DistinguishedName + "))"
Dim res = srch.FindOne()
If res IsNot Nothing Then
GoogleCheck = True
Else
GoogleCheck = False
End If

Find a variable with concatenation

I would like to find a variable with concatenation.
Exemple :
Dim oExcelRangeArray1(0, 0) As Object
Dim oExcelRangeArray2(0, 0) As Object
Dim oExcelRangeArray3(0, 0) As Object
For i As Integer = 1 To 3
oExcelRangeArray & i = xl.Range("A1:Z400").Value
Next
but oExcelRangeArray & i doesn't work.
Thank you
For the extent of my knowledge, there is no way to achieve what you are trying to do directly, because oExcelRangeArray & i will not be evaluated as a separate step before the variable assignment happens.
In my mind you have two choices:
Assign each variable individually,
oExcelRangeArray1 = x1.Range("A1:Z400").Value
oExcelRangeArray2 = x1.Range("A1:Z400").Value
oExcelRangeArray3 = x1.Range("A1:Z400").Value
oExcelRangeArray4 = x1.Range("A1:Z400").Value
Or, add each array to a list, and iterate through it,
Dim oExcelRangeArrayList As New List(Of Object)
oExcelRangeArrayList.Add(oExcelRangeArray1)
oExcelRangeArrayList.Add(oExcelRangeArray2)
oExcelRangeArrayList.Add(oExcelRangeArray3)
oExcelRangeArrayList.Add(oExcelRangeArray4)
For i As Integer = 0 To 3
oExcelRangeArrayList(i) = x1.Range("A1:Z400").Value
Next
[Note: Writing this freehand without checking it, code may not be verbatim; hopefully you get the concept. Corrections welcome.]

VisualBasic 2010 - merge 2 strings and read them as a variable

i have this code, and i want to access some variables.
Dim k1 as String = "Something"
Dim k2 as String = "Something"
... to k230
------------------Then i have this:
Dim rnd = New Random()
Dim nextValue = rnd.Next(230)
For i = 0 To 230
If nextValue = i Then
MsgBox('k+i') <--BUT READ THIS AS A VARIABLE.
End If
i = i + 1
Next
i readed some similar questions, but them doesn't apply to this case.
Consider using arrays here:
http://msdn.microsoft.com/en-us/library/vstudio/wak0wfyt.aspx
An array is a set of values that are logically related to each other,
such as the number of students in each grade in a grammar school.
By using an array, you can refer to these related values by the same
name, and use a number that’s called an index or subscript to tell
them apart. The individual values are called the elements of the
array. They’re contiguous from index 0 through the highest index
value.
Try using a Dictionary:
Dim k As New Dictionary(Of Integer, String)()
k.Add(1, "Something")
k.Add(2, "Something")
'... to 230
Messagebox.Show(k(i))

Display all contents of a "table" created in LINQ in VB.NET

Working from a previous question I asked (which was answered very well).. Ive come across another snag... In the following code
Public Sub Main()
Dim EntireFile As String
Dim oRead As System.IO.StreamReader
oRead = File.OpenText("testschedule.txt")
EntireFile = oRead.ReadToEnd
Dim table As New List(Of List(Of String))
' Process the file
For Each line As String In EntireFile.Split(Environment.NewLine)
Dim row As New List(Of String)
For Each value In line.Split(",")
row.Add(value)
Next
table.Add(row)
Next
' Display all contents of 5th column in the "table" using LINQ
Dim v = From c In table Where c(5) = ""
For Each x As List(Of String) In v
Console.WriteLine(x(0)) ' printing the 1st column only
Next
Console.WriteLine("Value of (2, 3): " + table(1)(2))
End Sub
`
The area where it says Dim v = From c In table Where c(5) = "" the blank quotations will only accept a specific number that its looking for in that column.
For Example:
Dim v = From c In table Where c(5) = "7" Will only show me any 7's in that column. Normally there will be many different values and I want it to print everything in that column, I just cant figure out the command to have it display everything in the selected column
Once again Many MANY Thanks!
If you want to show all rows (to be precise: items in the IEnumerable), just remove the Where condition
Dim v = From c In table
Just a note: table is not a very good name for your list, it leads the thought to SQL. This is just Linq2Objects and you don't query tables you query plain objects with a syntax very similar to Linq2SQL that in turn is heavily inspired by SQL.