I'm wondering if it's possible in VB.NET to make similar properties call one generic one?A sentence doesn't explain it well so here's a code example.I have a bit field defined like this:
<Flags()> _
Enum E_Operation As Integer
Upload = 1
[code]....
We have migrated our Vb6 application to VB.NET using a third party tool. Now we are in a process of Refactoring and introducing object oriented concepts in the application.
In VB6, we were using structures in many places. As a part of introducing object oriented programming,
1. is it a good idea of changing all Structures to Classes? or Is there a concept of "Generic Structure" similar to Generic collections, Generic classes?
2. Can some one guide me any source containing guide lines or best practices for applications that are migrated to VB.NET from VB6 and implementing object oriented programmaing.
I have created a simple application where I fetch questions from an Access database and store the answers to another Access database. I am not sure how many questions client would like to ask, so I can't hardcode that number.
So, column names for answers table (besides user information like first, last name and so on) will be a1, a2, a3 ... aN.
And finally the problem!
For testing purposes I have hardcoded saving first 3 answers like this:
newEntry.a1 = answers(0)
newEntry.a2 = answers(1)
newEntry.a3 = answers(2)
Now I would like to iterate through all properties based on count of "a-type" properties:
'aCount is number of "a-type" properties
For i = 0 To aCount - 1
Dim property As String
property = "a" & (i + 1)
newEntry.property = answers(i)
Next
Of course, above code does not work, it is just a pseudo-code idea that "should" to the same as my hardcoded example.
Is it possible to iterate through predefined properties of newEntry object in that manner?
I'm trying to create a class for storing data on People with another class to store their Bank Transactions.Ideally, this all be hidden away and leave only simple statments, declarations and functions available to the programmer.[code]I know this is possible as these exist in the Listbox Class though can't figure out how it's done.
View 2 RepliesI want to pass a List of T where T is an object I've created that has about ten properties (strings, dates and integers).The lst passes to the function successfully. I am also passing an New T of the Object (itm as T).I can see all the values (see image below), but because it's generic I cannot seem to retrieve the property values and I cannot figure out how to iterate through the properties of each itm as they are retrieved in the For Each.[code]
View 10 RepliesI have a class which extends HashSet(Of T).I am trying to evaluate some custom properties of this HashSet during execution and make decisions based on those values.
During debugging, I am pausing execution and adding a Watch on my instance of this HashSet.
The Watch only provides me with a view of the Count of the HashSet and the objects contained by the HashSet.How can I get the Watch to show me the other properties of the HashSet?
Currently my code has the following properties:
[Code]...
I need to return an a generic list in the correct order for my project, and I'm getting InvalidCastException errors. Here is the code:
Dim lDt As List(Of Comment) = RemapCommentsForE1(so.CommentList). _
OrderBy(Function(x) x.CreateDate.Value). _
ThenBy(Function(x) x.Sequence). _
[code].....
[code]I want to make the Properties Window to update the properties for X and Y at each MouseMove, so they become immediately visible for the user.
View 2 RepliesI know about the existence of System.Nullable(Of T) Structure.I am trying to write a class to replace it: The Nullable(Of T) Class [VB code below]. But when I tested the Nullable(Of T) Class (See NullableOfTClassTest Class, Method Main) an exception occurs when using the CType operator to convert from System.Int32.Why does this happen at runtime, why isn't my Ctype operator method being called?
NOTE: code below reordered and reduced in order to hilite problem.
Namespace MyNamespace
Public NotInheritable Class NullableOfTClassTest
Private Sub New()
End Sub
[Code]...
I am trying to essentially convert an Excel spreadsheet into a Windows Form. On the first worksheet I have setup an IF statement to work as a search function =IF(C10="","",VLOOKUP(C10,'Price List'!$A$2:$D$40008,2,FALSE)) to read a price list on a separate worksheet. It works by taking a partnumber then puts the description in the next column (description column) and then the price in the "price each" column then finally totalling the row based of the quantity selected (see below).[code]...
View 11 RepliesBasically I'm trying to make a file browser similar to what XBMC has, a file browser that you navigate with your arrow keys.This is the custom UserControl I made:
The small box on the left will be an icon, I will have a custom icon for directories/files. The label box that says title will be the name of the directory/file.
What I need to know is How to get the name of the directory/file so I can change the Title labelbox text to match the name.How to distinguish whether it's a file or a directory so I can set the picturebox to the right icon.How to create a new UserControl for each directory/file
If I'm not mistaken PHP crypt() function use DES-based encryption algorithm. So I've search DES Encryption code and all that I found is code that similar to the one in this post http://www.vbforums.com/showthread.php?t=471798
But with those codes I must enter 8 character lenght salt. Less then that the code wouldn't succeed. In the other hand. The PHP crypt() function only could use 2 character length salt. If you enter more than that, it seems it only use the first 2 character..[URL]
How can I call multiple objects? Example..
nameTextbox.Enabled
addressTextbox.Enabled
ContactTextbox.Enabled
How can I call this objects with same properties...
So rather than typing them all with =True or False...
I just have to type a variable = True or false...
And where will I type the code.
I have a class like this:
Public Class MyClass
Private _intList As New List(Of Integer)
Private _avg As Decimal
[code]....
The Getter is calculating average and calls Setter to save the value. For some reason I cannot understand, the average is always 0. For example:
Dim c As New Class2()
c.Add(1)
c.Add(2)
c.Add(3)
Console.WriteLine(c.Avg.ToString()) ' This will print 0
What is the cause of this?
I'm making a seat booking system in vb.net (WinForms) and I need the user to be able to select the seat they wish to use and for it to change colour (so they can tell that it selected).
I began to try using buttons, but 480 buttons seriously slowed down the load time for the form. I then tried a data grid view with buttons in the rows/columns, but couldnt make that work properly.
Would it be worth trying to use 480 picture boxes and change their background colour? Or would that just slow the form down the same way as 480 buttons?
I have a WPF Keyboard Application, it is developed in such a way that an application could call it and modify its properties to adapt the Keyboard to do what it needs to. Right now I have a file *.Keys.Set which tells the application (on open) to style itself according to that new style. I know this file could be passed as a command line argument into the application. [code]...
View 1 RepliesIs there a way to call a running application (my own) and read properties from it? In this case read and get a collection of objects and put it into a similar collection.
View 4 RepliesIm looking to make a desktop app that will be similar to the doodle function in yahoo messenger but with a loaded background image to draw on. I was thinking of using a P2P/IP chat on the side.Im just starting with vb most of my coding has come from actionscript
View 3 RepliesI have an abstract class in VB.NET. I want all classes that inherit from this class to return whatever value makes sense. For example, it could be an Decimal, Integer, String. How can I delcare the function in the abstract base class to allow for this? Is this even possible?
[Code]...
I can create classes that use generics, however I was wondering if it is possible to apply this to a shared method rather than rely on the caller casting to the correct type.This is the method:
Public Shared Function DeserializeObject(ByVal serializedXml As String, ByVal givenType As System.Type) As Object
Dim serializer As New XmlSerializer(givenType)
Return serializer.Deserialize(New IO.StringReader(serializedXml))
End Function
I'm pretty sure this can't be done, but thought I'd check (if so Extra points will be awarded if someone can technically explain why the compiler can't do this)..
I have a utility class that takes a generic list as a parameter.Code looks like:
Function DoStuff(collection as Object, elt as Object)
...
collection.Add(elt)
[code]....
Currently I have written a function to deserialize XML as seen below.How do I change it so I don't have to replace the type every time I want to serialize another object type ? The current object type is cToolConfig. How do I make this function generic ?
Public Shared Function DeserializeFromXML(ByRef strFileNameAndPath As String) As XMLhandler.XMLserialization.cToolConfig
Dim deserializer As New System.Xml.Serialization.XmlSerializer(GetType(cToolConfig))
Dim srEncodingReader As IO.StreamReader = New IO.StreamReader(strFileNameAndPath, System.Text.Encoding.UTF8)
Dim ThisFacility As cToolConfig
[code]....
I'm trying to create a base interface for a class of mine that uses generics. However, I cannot figure out how to declare a property of the interface when its type won't be defined until the class is initialized.
To clarify, consider List(of T), which according to msdn, implements IList (among other things). Note that IList is not the same as its generic counterpart IList(Of T). So that mean any List(of T) can be converted to IList, which simply returns an object for its items. That's what I want to do with MyClass(of T), be able to cast it as IMyClass regardless of what T is.
But when I try such as:
Interface IMyClass
Prop A as Object
Class MyClass(of T) Implements IMyClass
Prop A as T Implements IMyClass.A
I get a signature error for the last line, even though object is broader than T. What am I doing wrong, or how exactly did Microsoft manage to make List(of T) implement IList?
I am looking to make a "user.settings" file or something similar that stores information for my application. I'm not sure how I would read a text file per line and do something depending on what it says.
View 7 RepliesIs it possible in Visual Basic to make a Windows form vibrate randomly for a few seconds, similar to an "earthquake" effect?
View 3 RepliesI'm doing a project for school. I'm trying to make a game similar to the Impossible game. I need a square (picturebox) to jump but I want gravity to effect it.
View 1 RepliesConsider:
Public MustInherit Class Column
Public ReadOnly Property ReturnSomethingUseful() As Object
Get
'return something useful
[code]....
But this gives the following error:
Public Overrides Function ParseValue(sValue As String) As Boolean'
cannot override 'Public Overridable Function ParseValue(sValue As String) As Object'
because they differ by their return types.
I accept that you can't do this, but I'd like to be able to preserve the semantics of what I'm. trying to do, which is to have an untyped version that deals with Object, but a typed version in derived classes that knows about the specific type T.
I have a Journal that records entries for different types: Journal(Of ParentT)
[Code]....
I am trying to construct a generic interface class with generic functions. My goal was to use this to implement multiple worker classes for database interaction that have the same basic functionality. Each class will deal with different object for example, category, product or supplier but unless the the functions in the interface are generic that this won't work.This is the interface code that I have but I don't know if I have done it correctly. [code]
View 2 Replies
