In a project of mine I'm currently doing this:
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all classes inherit docMain and addTemplateToList( X ) adds x to a List(Of docMain). Now my question is: Is there a better way to do what's done in the code sample? I thought of something like:
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Is this somehow possible in VB.net (Reflection?)?
I have a question that regarding the initialisation and setup at the daily startup of a winform app.The startup requires a httprequest to login to a remote website, to obtain a cookie container for later processing. It uses the Keep Alive method to stay open as long as the sub is open.
My question is (perhaps naiive?) how can I keep the cookie container, and any other variables stored in memory kept there so they stay in scope while I the application is doing other things throughout the day?
For example, I have a sub in a class that takes care of the login to the web site and stores the cookies, once the sub ends, the cookie jar empties out. I could keep loging in again but that seems like extra processing to call the process instead of jsut keeping it in memory. I guess I could write the cookies out to a table and read back in, but perhaps there is simpler way?
why this gives an error at run-time:
Dim mightBeNothing As List(Of String) = Nothing
Dim a As List(Of String) = IIf(mightBeNothing Is Nothing, New List(Of String)(), New List(Of String)(mightBeNothing))
I am getting ArgumentNullException on the second line. If I replace the last part with:
Dim a As List(Of String) = IIf(mightBeNothing Is Nothing, New List(Of String)(), New List(Of String)())
It works - but the constructor New List(Of String)(mightBeNothing) will never be called if mightBeNothing is nothing, so what is the issue?
I downloaded a .net component that I would like to make consumable by COM clients. This component allows one to create a DXF file (Cad drawing). The problem is that the component is composed of quite a few class files, some inherit another. All the examples I found only show one file no namespaces etc. [Code]
View 1 RepliesI want to use this Structure in multiple .vb files within my project:
Structure MyStruct
Dim Name As String
Dim Good As Boolean
End Structure
If I define it in one file, the other files can't use it. How do I define it globally?
I am having trouble while installing Visual Basic 6.0 . Setup gives message
View 5 RepliesI have created a read-only property(name) in class1. How can I use this name property in class2?
Public Class Class1
ReadOnly Property name() As String
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Can I directly carry this name variable value into class2?
I am wondering the best way to store an object in memory that is used in a lot of classes throughout an application. We have multiple databases, 1 per customer. We also have a master table and each row is detailed information about the databases such as database name, server IP it's located and a few config settings.
I have an application that loops through those multiple databases and runs some updates on them. The settings I mentioned above are updated each loop iteration into memory. The application then runs through series of processes that include multiple classes using this data. The data never changes during the processes, only during the loop iteration.
The variables are related to a customer, so I have them stored in a customer class. I suppose I could make all of the members shared or should I use a singleton for the customer class? I've never actually used a singleton, only read they are good in this type of situation. Are there better solutions to this type of scenario? Also, I could have plans for this application to be multithreaded later.
I'm a long-time developer but semi-new to Visual Studio .NET and VB.NET. I've been working on an application for months, written in Visual Basic .NET. It's a rewrite of a popular IDE of mine that's originally written in assembly. What I'm trying to do in VB.NET is have multiple TabPage classes that inherit from TabPage, ofcourse, but each having it's own methods for common functions like Cut, Copy, Paste, etc. so that when I call tab.Cut(), the TabPage class for the currently-selected tab is the one used. In each custom TabPage class, I'll have a New instance of the main control that goes in that tab.
I think there would be a problem when I loop through the TabPages since the Foreach routine can only use one object type, as far as I know (TabPage).Currently I have only one custom TabPage class called Page that obviously inherits from TabPage, has additional properties and also methods that allow editing functions for whatever control is selected to be displayed for the tab. For example, when I call the New constructor, I supply the editor type as a parameter: dim tab as New Page(HEX_EDITOR).I have edit controls such as text, syntax editor, hex editor, bitmap editor, HTML editor, HTML browser. This means I get a new instance of all of those controls each time a new Page is added to the TabControl. I'm currently disposing of the unneeded editors depending on which editor is the one needed. The scheme is not preferred but it works great for now as I work on other areas of the IDE.
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I have one class with <Serialize> attribute called Tree. And Tree class has an arraylist of TreeNode classes. Is it possible to use Soap to convert the Tree class and arraylist of TreeNode classes to one xml file or binary file? If it is possible, do i need to use <Serialize> attribute on TreeNode classes too? If not, what should i do then?
View 3 RepliesI am integrating two disparate data sources where each value may depend on one or more other derived elements.This app runs as a windows service.Currently all my code is in a single class.I am upgrading to 2010 and wondering if best practices would be to break out my functions into multiple classes - there are over 100 data elements that need to be constructed. The following is an example of a couple derived items:(Is there a better way to do this - when complete I will pass this app off to someone else to support and want to make sure I give them the best beginning.[code]......
View 2 RepliesIs it possible to have multiple classes in a namespace and be able to reference the functions within the clases if the Major class is instaniatated from another class?? for instacnce:
Namespace Database
Public Class Data
Public Class Prepare
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I'm still teaching myself how to bind and use observable collection. One problem that I'm a little confused on is binding multiple classes/observable collection to one page. In other words, if I have a PersonName class and a AnimalName class, I have to create two separate observalbe collections for each? How would I set the datacontext when a page only allows one?
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Now If I add another class, how would I combine the two on the binding part and collection part.
Okay, say I have a class named "ChannelList", and it raises an event named "FoundChannel"
But what I'M wanting to do is create multiple classes of different names that use that class, but I want to have all of the "FoundChannel" events be handled under one single sub routine?
I want to be able to incorporate some constant definitions and enum types in multiple classes of mine.Something akin to including a header file in C++. How do I do this best in VB.NET? I'm having a hard time because the only way I can see to do it is to inherit a class with the definitions in it but there is no multiple inheritance in vb.net so I am having some issues with that.
View 6 Replieswhile making my irc bot i need to send many different irc commands such as join channel, change mode, kick user message, topic channel message and so on. All these commands are currently process individually in a public sub on the irc connection thread.
Public Sub Write(ByVal command As String)
_streamWriter.WriteLine(command)
_streamWriter.Flush()
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Would you have a load of public sub's to handle each or maybe something else?
I'm developing a new functionality for web site project with VB.NET default language in VS 2008. As my preferred language is C# I create subfolder for C# code in the App_Code folder and add appropriate codeSubDirectories element to web.config file. The problem is that I can't refer VB.NET classes in my C# code. All VB.NET classes and structures are placed in global namespace in the App_Code. But even if I place some VB.NET class in the same namespace I've use for my classes in C#, I still can't use them.
View 2 RepliesI would like to know how will performance go when I instantiate multiple classes in one form.e.g
Public Class frmClass
Dim obja As New ClassA
Dim objb As New ClassB
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We are developing a webservice for a client. We are not supose to throw SoapExceptions, so instead, we catch every exception server side, and return a custom Exception class.
Public Class Order
...
End Class
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The problem now is, that since my webmethod is returning the type [Object]. The wdsl that is generated does not contain the order, or the exception.
I can change the [Object] to [Order] Or [MyException], but only one of them is generated in the wsdl.
I want both the MyException type and the Order type in my wsdl, but i just cant get it working.
I am in college taking computer programming and we are now in multiple classes and forms. It was very hard to get ahold of at first but now that I understand it a bit better I am curious as to how often in a professional enviornment do developers create multiple classes for a project? Besides the use of custom functions what else is beneficial for it?
View 4 RepliesI will attach a pic of the errors I have left to resolve. And in addition, when I run it, it doesn't put the CustName and AcctNo in the ListBox. I could attach more code to get a bigger picture of what I'm trying to do. Here is where I have the errors on the list:
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2. FunctionLayer -deals with Common Operations which get results from DataLayer and return results to Forms.3. User - deals with User. (For Reusing the User Class in other projects, i have separated this class)Here in Class2 - I have an instance of Class1( ie., DataLayer) for DB Operations.imilarly in Class3- I have an instance of Class1( ie., DataLayer) for DB Operations.Now in my form, If i create Instance of Class2. But When I need user functionality in this form, I have to create an instance of Class3 to this form.
View 6 RepliesHere's what I've got thus far:
Dim xpDoc As New XPathDocument(strXmlUrl & strXmlInfo(0) & "?xml=1")
Dim xpNav As XPathNavigator = xpDoc.CreateNavigator()
Dim xpExpression(9) As XPathExpression
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My VB project is large enough that it requires several files. It was originally developed as a Console App and I created each file as a MODULE. All modules could use subroutines, data structures and constants from other MODULES and everything worked fine. I needed to add basic windowing to the app and this required that the app be converted from a Console App to a Windows Forms App. The main window is Form1 which is not a MODULE but a CLASS. The problem is that some MODULE based functions cannot access subroutines, data and constants that are defined within the CLASS Form1 unless they are incorporated into the CLASS file and this makes the CLASS file very large. If I add a new Class file to the project, it also cannot interoperate with Class Form1 in the same way that multi-MODULE code interoperates.
How does one spread CLASS code across several files and still allow it to interoperate as if it were in a single file? Alternatively, how does one create several CLASS files that operate the way multiple MODULE files operate.I am sure that there are all kinds of best practices that I am violating but the goal to to get some prototype software working and interfaced to some lab equipment.
I am having this strange thing happen where I have a Module that contains multiple classes in my project. In the Solution Explorer, the module shows up as a Windows Form and if I double click on it to open it, it tries to open the Form Designer. What could be causing VS to think that it is a Windows Form instead of a module?
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I have an small physics toy application I am developing. It works fine except the particles will not push each other away, only pull towards, I debugged that sub going through it command by command and realised the value 'H' would not change, what ever it was set to during the first pass through the sub is what it kept, the only way to change this value is to manually set it i.e 'h = 1'. Once the calculation is redone on the 'H' value it resets to what it was previously, even though the x1,y1,x2,y2 are all different, thus meaning H should be different.
I think it is me that has made a mathematical mistake somewhere, but I cannot see where it is. I need a fresh pair of eyes to look over my work. Please let me know if you find anything.
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I have been developing an antivirus using vb.net. The virus scanner works fine but I was thinking of ways to optimize the scanning speed (because large files take forever)
View 3 RepliesOk, the error I'm getting is "Load Report Failed" and it happens when I need to load a large number of crystal ReportDocument objects. I've searched on this, and there is a property in the registry that you can change to -1 and it allows to load more, however I'm still getting the error, just after I get about twice as many documents loaded.
The report is basically a one page document (for each client in the database with an interest charge). It displays the amount of interest charged, and other information pertaining to the charge. These documents are basically printed out and mailed to the client.
I created a "Print Preview" screen which has a CrystalReportViewer object, and an ArrayList property. The ArrayList property has an array of all reports, and there are next and back buttons to browse through each report. Once they are satisfied, they will print them all out, and I can dispose of the objects.
The solution for this, from everywhere I've seen, is to "Dispose the object after you are done with it". My problem is that I can't dispose it until they are finished with the print preview screen.
Is there a better way to go about this that won't require too much time to code (we are already over the deadline on this project) or a simple solution to get past the ReportDocument limit? Right now it is erroring on report 150., There are 180 records (as of today) that need to be loaded.
How can I Optimize my own code written by VB.net? Is there any tools for it? Does Visual Studio have any one? What's your suggestion? I use VS2008 as my editor.
View 1 RepliesI have a DataGridView where I bind a datasource (sql query) to it. The row count is high with many columns. Trying to scroll through this DGV is painfully slow.
Does anyone know of any kinds of optimization I can do so that I can scroll faster? Like what is the DataGrid doing when you scroll? Does it repaint every screenful? Does it validate every row? It seems like it is doing something unneeded when a user scrolls.