I am trying to create a settings class.
The Property Test() is a list of strings.
When I add a string such as: t.test.Add("asasasAAAAA")
I want it to autmatically turn lowercase.
For some reason it is not. Any Ideas?
p.s.
using t.test.Add(("asasasAAAAA").ToLower) will not work for what I need.
Thank you.
Public Class Form1
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim t As New Settings
t.test.Add("asasasAAAAA")
t.test.Add("aBBBBBAAAAA")
t.test.Add("CCCCCsasAAAAA")
End Sub
End Class
Public Class Settings
Private strtest As New List(Of String)
Public Property test() As List(Of String)
Get
Return strtest
End Get
Set(ByVal value As List(Of String))
For i As Integer = 0 To value.Count - 1
value(i) = value(i).ToLower
Next
strtest = value
End Set
End Property
End Class
ashakjs
That's the reason: set accessor of your property is actually never called.
when you use t.test.Add("asasasAAAAA") you are actually calling a get accessor, which returns a list, after that specified string is added to this list, so .ToLower function is never called.
Simple way to fix this:
Dim list as New List(Of String)
list.Add("asasasAAAAA")
list.Add("aBBBBBAAAAA")
list.Add("CCCCCsasAAAAA")
t.test = list
Alternatively, you can implement your own string list (easiest way - inherit from Collection (Of String)), which will automatically convert all added string to lower case.
What you are trying to do and what you are doing don't match. To do what you want, you need to create your own collection class extending the generic collection - or provide a custom method on your settings class which manually adjusts the provided string before adding it to the local (private) string collection.
For an example of the second option, remove the public property of the settings class which exposes the list of string and use a method like the following:
Public Sub Add(ByVal newProp As String)
strtest.Add(newProp.toLower())
End Sub
Related
I have a DLL with several properties and a function that generates runs a SSRS report in the background and saves it to a PDF file.
I have a DataTable with all the reports that need to be generated and where they need to be saved.
I want to make each instance of the DLL run in a separate thread. I took a stab at it found the 2nd row in the DataTable overrode the first row.
Here is the Class/DLL Code
Public Class SSRSFunctions
Private Shared _Formated_Parameters As String
Private Shared _Report_Parameters As Dictionary(Of String, String)
Public Property FORMATED_PARAMETERS() As String
Get
Return _Formated_Parameters
End Get
Set(ByVal value As String)
_Formated_Parameters = value
End Set
End Property
Public Sub New()
_Report_Parameters = New Dictionary(Of String, String)
End Sub
Public Function RenderReportToFile() As String
'RenderReportHere
End Function
Public Sub AddParameter(ByVal Name As String, ByVal Value As String)
If _Report_Parameters.ContainsKey(Name) Then
_Report_Parameters.Remove(Name)
_Report_Parameters.Add(Name, Value)
Else
_Report_Parameters.Add(Name, Value)
End If
End Sub
End Class
Here is the calling Code
Private Sub CheckForNewRequests()
'Filter DataTable for Reports to Run
For Each dr As DataRow in DateTable.Rows
Dim rpt As New SSRSFunctions
Dim t1 As New Threading.Thread(AddressOf StartNewThread)
rpt.FORMATED_PARAMETERS = (dr("REPORT_PARAMS"))
t1.Start(rpt)
Next
End Sub
Private Function StartNewThread(ByVal report As SSRSFunctions) As String
Return report.RenderReportToFile()
End Function
I am trying to figure out why the "Dim rpt As New SSRSFunctions" is not creating a new instance of the DLL and so the second row of the dataTable has a new instance to store it's parameters.
The second row is overriding the first.
Help?
Thanks
jlimited
Dont make the private properties shared, remove the Shared keyword from the declarations.
change
Private Shared _Formated_Parameters As String
Private Shared _Report_Parameters As Dictionary(Of String, String)
to
Private _Formated_Parameters As String
Private _Report_Parameters As Dictionary(Of String, String)
By sharing them you are saying that no matter how many instances of the class is created always use (share) the same instance of the shared internal variable.
Public Class notifierMain
Public Class Contacts
Inherits List(Of row)
Public Sub New()
Dim r As New row()
Me.Add(r)
End Sub
Public Class row
Public Sub Validate()
Dim curType As String = Me.GetType().ToString
End Sub
End Class
End Class
Public Class MyContacts
Inherits contacts
End Class
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim c As MyContacts = New MyContacts()
c(0).Validate()
End Sub
End Class
When I debug this winforms application I get curType = "notifier.notifierMain+Contacts+row"
I want to the Validate function to know it is in MyContacts. How do I do this?
You're tostring()'ing gettype which returns a property called full name.
just check the .Name after get type and that'll have the result you want.
btw: this is a weird example, if you want validate() to return the name of the class you'll have to declare it as a function.
:)
The Me.GetType() is always going to return the type of the class it is enclosed in.
You will need to change Validate to a function and pass in the type of object being validated, but then you might as well call c(0).GetType() outside if the validation anyway!
See MSDN documentation for GetType
You can explore your generic type as shown in this MSDN article:
http://msdn.microsoft.com/en-us/library/b8ytshk6.aspx
Hope this helps.
The code below works for the class that I hard coded "XCCustomers" in my RetrieveIDandName method where I use CType. However, I would like to be able to pass in various classes and property names to get the integer and string LIST returned. For example, in my code below, I would like to also pass in "XCEmployees" to my RetrieveIDandName method. I feel so close... I was hoping someone knew how to use CType where I can pass in the class name as a string variable.
Note, all the other examples I have seen and tried fail because we are using Option Strict On which disallows late binding. That is why I need to use CType.
I also studied the "Activator.CreateInstance" code examples to try to get the class reference instance by string name but I was unable to get CType to work with that.
When I use obj.GetType.Name or obj.GetType.FullName in place of the "XCCustomers" in CType(obj, XCCustomers)(i)
I get the error "Type 'obj.GetType.Name' is not defined" or "Type 'obj.GetType.FullName' is not defined"
Thanks for your help.
Rick
'+++++++++++++++++++++++++++++++
Imports DataLaasXC.Business
Imports DataLaasXC.Utilities
Public Class ucCustomerList
'Here is the calling method:
Public Sub CallingSub()
Dim customerList As New XCCustomers()
Dim customerIdAndName As New List(Of XCCustomer) = RetrieveIDandName(customerList, "CustomerId", " CustomerName")
'This code below fails because I had to hard code “XCCustomer” in the “Dim item...” section of my RetrieveEmployeesIDandName method.
Dim employeeList As New XCEmployees()
Dim employeeIdAndName As New List(Of XCEmployee) = RetrieveIDandName(employeeList, "EmployeeId", " EmployeeName")
'doing stuff here...
End Sub
'Here is the method where I would like to use the class name string when I use CType:
Private Function RetrieveIDandName(ByVal obj As Object, ByVal idPropName As String, ByVal namePropName As String) As List(Of IntStringPair)
Dim selectedItems As List(Of IntStringPair) = New List(Of IntStringPair)
Dim fullyQualifiedClassName As String = obj.GetType.FullName
Dim count As Integer = CInt(obj.GetType().GetProperty("Count").GetValue(obj, Nothing))
If (count > 0) Then
For i As Integer = 0 To count - 1
'Rather than hard coding “XCCustomer” below, I want to use something like “obj.GetType.Name”???
Dim Item As IntStringPair = New IntStringPair(CInt(CType(obj, XCCustomers)(i).GetType().GetProperty("CustomerId").GetValue(CType(obj, XCCustomers)(i), Nothing)), _
CStr(CType(obj, XCCustomers)(i).GetType().GetProperty("CustomerName").GetValue(CType(obj, XCCustomers)(i), Nothing)))
selectedItems.Add(Item)
Next
End If
Return selectedItems
End Function
End Class
'+++++++++++++++++++++++++++++++
' Below are the supporting classes if you need to see what else is happening:
Namespace DataLaasXC.Utilities
Public Class IntStringPair
Public Sub New(ByVal _Key As Integer, ByVal _Value As String)
Value = _Value
Key = _Key
End Sub
Public Property Value As String
Public Property Key As Integer
End Class
End Namespace
'+++++++++++++++++++++++++++++++
Namespace DataLaasXC.Business
Public Class XCCustomer
Public Property CustomerId As Integer
Public Property CustomerName As String
End Class
End Namespace
'+++++++++++++++++++++++++++++++
Namespace DataLaasXC.Business
Public Class XCCustomers
Inherits List(Of XCCustomer)
Public Sub New()
PopulateCustomersFromDatabase()
End Sub
Public Sub New(ByVal GetEmpty As Boolean)
End Sub
End Class
End Namespace
'+++++++++++++++++++++++++++++++
Namespace DataLaasXC.Business
Public Class XCEmployee
Public Property EmployeeId As Integer
Public Property EmployeeName As String
End Class
End Namespace
'+++++++++++++++++++++++++++++++
Namespace DataLaasXC.Business
Public Class XCEmployees
Inherits List(Of XCEmployee)
Public Sub New()
PopulateEmployeesFromDatabase()
End Sub
Public Sub New(ByVal GetEmpty As Boolean)
End Sub
End Class
End Namespace
From MSDN
CType(expression, typename)
. . .
typename : Any expression that is legal
within an As clause in a Dim
statement, that is, the name of any
data type, object, structure, class,
or interface.
This is basically saying you can't use CType dynamically, just statically. i.e. At the point where the code is compiled the compiler needs to know what typename is going to be.
You can't change this at runtime.
Hope this helps.
Since List(Of T) implements the non-generic IList interface, you could change your function declaration to:
Private Function RetrieveIDandName(ByVal obj As System.Collections.IList, ByVal idPropName As String, ByVal namePropName As String) As List(Of IntStringPair)
And then your troublesome line would become (with also using the property name parameters):
Dim Item As IntStringPair = New IntStringPair(CInt(obj(i).GetType().GetProperty(idPropName).GetValue(obj(i), Nothing)), _
CStr(obj(i).GetType().GetProperty(namePropName).GetValue(obj(i), Nothing)))
Of course, you could still have the first parameter by Object, and then attempt to cast to IList, but that's up to you.
ctype is used to convert in object type.
I need to cast, in the better way, two objects of two types of two custom-classes (in VB.Net):
The code:
Public Class pluto
Public Sub New(ByVal campoPippoPass As String)
_campoPippo = campoPippoPass
End Sub
Private _campoPippo As String = ""
Public Property campoPippo() As String
Get
Return Me._campoPippo
End Get
Set(ByVal value As String)
If Not Object.Equals(Me._campoPippo, value) Then
Me._campoPippo = value
End If
End Set
End Property
End Class
Public Class pippo
Public Sub New(ByVal campoPippoPass As String)
_campoPippo = campoPippoPass
End Sub
Private _campoPippo As String = ""
Public Property campoPippo() As String
Get
Return Me._campoPippo
End Get
Set(ByVal value As String)
If Not Object.Equals(Me._campoPippo, value) Then
Me._campoPippo = value
End If
End Set
End Property
End Class
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Dim a As New pippo("ciao")
' here I have the error 'invalid cast'
Dim c As pluto = CType(a, pluto)
MsgBox(c.campoPippo)
End Sub
How can I convert "c" into an "a" type object? Is there another way than writing the following?
Dim c As New pluto(a.campoPippo)
In the case of a more complex class, it could be more easy if there was a function for the conversion.
Firstly, I'm assuming the line: Dim c As pluto = CType(b, pluto) is a mistype and should actually be Dim c As pluto = CType(a, pluto)?
You can't cast one class to another unless they're related. You might need to explain what you're trying to do otherwise my answer would be, why are you creating the different classes pluto and pippo if they seem to be identical? Just create the one class and create two objects of it.
If you do need separate classes, maybe they are related in some way and you could make pippo inherit from pluto? Or make both of them implement the same interface.
In general I'd also suggest that it might be worth translating your class/variable names to English since that might make it easier for people to understand what you're trying to do.
I've created a custom user control that has several properties. One specifies which database I want the control to access. I want to be able to present the user of the control a drop down from which he can select which database the control will interact with.
How do I get the dropdown to work? I can get default values, but have yet to figure out how to get the selectable list.
Any help is apprectiated.
Thanks.
Marshall
You just need to attach your own TypeConverter to your property. You will override the GetStandardValuesSupported and GetStandardValues methods (maybe GetStandardValuesExclusive too) to return the list of databases you want to show.
If you are new to the PropertyGrid and the TypeConverter, here is a document.
It turns out to be simpler than I thought.
I had an enumeration set up for the property, but was having trouble using it for the property type. Said it was unaccessable outside of the class.
Then I had a 'duh' moment and changed the enumeration from Friend to Public, and then I was able to use the enumeration as the property type. As a result the values from the enumeration are listed in a dropdown when I look at the values for that property of the controls.
Thanks to all that answered.
Marshall
I'm a little confused about your problem.
If your user control contains a DropDownList control, just inititalize somewhere in the user control.
The easiest way is in the Codebehind for the usercontrol, just do DropDownList.Items.Add() or whatever the syntax is for adding an item.
Here is the template I use to create a custom datasource for my comboboxes:
Private Class Listing
Private _List As New ArrayList
Public Sub Add(ByVal ItemNumber As Integer, ByVal ItemName As String)
_List.Add(New dataItem(ItemNumber, ItemName))
End Sub
Public ReadOnly Property List() As ArrayList
Get
Return _List
End Get
End Property
End Class
Private Class dataItem
Private _ItemNumber As Integer
Private _ItemName As String
Public Sub New(ByVal intItemNumber As Integer, ByVal strItemName As String)
Me._ItemNumber = intItemNumber
Me._ItemName = strItemName
End Sub
Public ReadOnly Property ItemName() As String
Get
Return _ItemName
End Get
End Property
Public ReadOnly Property ItemNumber() As Integer
Get
Return _ItemNumber
End Get
End Property
Public ReadOnly Property DisplayValue() As String
Get
Return CStr(Me._ItemNumber).Trim & " - " & _ItemName.Trim
End Get
End Property
Public Overrides Function ToString() As String
Return CStr(Me._ItemNumber).Trim & " - " & _ItemName.Trim
End Function
End Class
And this is how I load it:
ListBindSource = New Listing
Me.BindingSource.MoveFirst()
For Each Row As DataRowView In Me.BindingSource.List
Dim strName As String = String.Empty
Dim intPos As Integer = Me.BindingSource.Find("Number", Row("Number"))
If intPos > -1 Then
Me.BindingSource.Position = intPos
strName = Me.BindingSource.Current("Name")
End If
ListBindSource.Add(Row("Number"), strName)
Next
cboNumber.DataSource = ListBindSource.POList
cboNumber.DisplayMember = "DisplayValue"
cboNumber.ValueMember = "Number"
AddHandler cboNumber.SelectedIndexChanged, AddressOf _
cboNumber_SelectedIndexChanged
Hope this helps. One thing to keep in mind is that if cboNumber has a handler already assigned to the SelectedIndexchanged event, you will encounter problems. So don't create a default event.