First time posting a question..I am trying to write to a table from a vb form and i am getting this message when executing the insertcommand:
Cannot call methods on char. The following is the code that i am using:
[Code]...
I tried the search (forum / google) before, but unfortunately I found no solution. From VB.NET I have to call a very old c-dll, the methods have signatures like this:[code]In VB I tried the method-declaration with IntPtr, FixedLengthString, Char(), Byte() and so on, but with no success. I now, that char* declarations can be handled with the Stringbuilder, but that seem not to work in this case, as the declaration is a char[256] and no pointer.So how to declare the c-method above to be used in VB.NET?
View 11 RepliesI will preface this by saying Im previously an asp developer and am learning oop programming/Vb.Net
Im working on a 3 tier architecture and trying to abstract my code as much as possible since I have a very large intranet to convert. In my business layer I am defining my classes with management methods. Below is an example of one of my classes.
My question: Is there a way for me to genericaly refer to the class type and object type so that I dont have to continualy refer to the class name/type "ServiceRequest" throughout the class. For example something like:
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I am coding in VB.Net, VS 2008. I wrote a console app that consumes 2 web methods from a web site application. I need to enhance this console app so that it launches the web methods continuously, perhaps every x minutes (during business hours), but never before the last invocation has terminated, whose duration may vary, depending on how many accounts there are to process.
Originally, I scheduled the application using Task Scheduler, but I think this doesn't prevent two invocations at the same time.
Although I have seen many posts on using timers, I haven't found exactly what I need.
So far I have:
Dim aTimer As New System.Timers.Timer()
AddHandler aTimer.Elapsed, AddressOf TriggerWebMethods
' Set the Interval to 10 minutes:
[Code]....
When should Timer.Elapsed be used vs. Timer.Tick? What is the difference between Timer.Enabled vs Timer.Start, and should I be selecting just one? I would like the 2nd web method to kick off when the first one is done.
I have 4 rounding options: None, Standard, Up, Down If they choose None and the number is 108.7879, I just want to display 108.78 with no rounding. I know I probably can use Math.Ceil for Up and Math.Floor for Down, but I am not sure what to use for None or Standard.
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There are no "non-public" or "static" methods in my code. All are public. What I'm trying to do is pass a FrameworkElement (more specifically a web browser control) that was created in one process over to another process for display and use. Also I'm not using (and would to avoid using) any of the framework 3.5 addin stuff.[code]
View 2 Repliesi want to read a character 1 by 1 from a string and a .txt, i know all about stream reader so for the .txt would it be somthing like:textbox1.text = tr.readCharacter.i would prefer to be able to read from a textbox or String array though.
View 10 RepliesI need validation for string to comply with next: no space char starts with one delimiter char ends with one delimiter char has no other char as delimiter char. Updated sorry missed that should only be one delimiter char at start and at the end
View 2 RepliesPublic Shared Function UrlTokenDecode(ByVal input As String) As Byte()
If (input Is Nothing) Then
Throw New ArgumentNullException("input")[code].....
I have a class like this:
[Code]...
It works, when I make getBar methods public, but I don't want to expose these unneccessarily. Why I can't call private shared methods from a public one in the same class is over my head. I'm using .net framework 4.0 in a web application.
I have written my own function, which in C would be declared like this, using standard Win32 calling conventions:int Thing( char * command, char * buffer, int * BufSize);I have the following amount of VB figured out, which should import the dll and call this function, wrapping it up to make it easy to call Thing("CommandHere",GetDataBackHere).UPDATE:This code is now a working solution, as shown here:
Imports Microsoft.VisualBasic
Imports System.Runtime.InteropServices
Imports System
Imports System.Text
[Code]...
Updates: I got the code to build by following the help received here, and then I had forgot the As Return Type (which got me a MarshalDirectiveException PInvokeRestriction). Then I had an assertion failure inside my DLL, which lead to an SEHException. Once fixed, this works BEAUTIFULLY. There are newsgroups where people are saying this can not be done, that VB only loads managed dll assemblies (which I guess is the normal thing most VB users are used to).
i am trying to increment a char in vb.net, eg: Dim letter As Char = "a"c. and i want to make it b, and so on. how can i do this?
View 1 RepliesThis is the original code in c#
public class CategoryRepository: RepositoryBase<Category>, ICategoryRepository
{
public CategoryRepository(IDatabaseFactory databaseFactory)
: base(databaseFactory)
[Code]...
Does anyone has an idea what i should change to let it work and let my UserRepository use the methods in RepositoryBase while implementing the IUserRepository?
how can I cut the 1st 3 char in a string in vb 2008?
For example:
Dim i As String = "ABCDEF";
I want to only cut the 1st 3 char and the system will only display "ABC" after the 'cut' action done.
how do you convert from char to keys?
View 3 RepliesI am working with a vb program, but there is something strange on one of my .vb code pagewhen i put the "dot" afther the object name its dont show the methods availables for this objectbut on other vb code pages i can see it. but in this one no.for exmaplethis is a piece of code: Dim sb As New StringBuilder()
View 3 RepliesI am not sure how clear my question is by the title, but I am trying to make Class methods instead of Instance methods in Visual Basic that way I don't have to waste memory and code creating temporary objects to execute methods that don't need instance variables.
I am not sure if you can do that in VB but I know you can in Objective-C by using either a "+" or "-" sign in front of the method declaration. And in C++ (at least I think, I can't remember) you put the static keyword or const keyword in front of the function.How would I do this in VB if it is possible? Or should I just make a separate set of functions that are not members of a class?
[code] Error4'Char' values cannot be converted to 'Short'. Use 'Microsoft.VisualBasic.AscW' to interpret a character as a Unicode value or 'Microsoft. VisualBasic.Val' to interpret it as a digit.
View 1 RepliesI need to strip every other char from an array or string. Whichever is easier.
View 4 Repliesis there any way to convert chinese characters to pinyin?i searched google and this is the nearest result that i found[URL]..HttpUtility.HtmlEncode(Text);
but it requires .net framework 4 if i'm not wrong.
currently i am using .net framework 3.5. is there any other way or web service that i can use?
i am using a c++ dll to control a usb device. a while back i created a vb6 program that interfaced with the dll.it worked perfectly.now i am trying to make one in vs2008.here is the header of the function i am trying to use in teh c++ dll [code]but this get no value for textbuffer.and after the function is called a few times it gives me a memory error. i think it is because the string is not fixed length.is there a way i can get this to work in vb.net without rewriting the dll
View 3 RepliesI have split a string into a char array, now i need to copy the char array to an int array with the ASCII values of each char.Donīt know how to do it without looping each value.
This is my code:
origen = RichTextBox1.Text.ToString
Dim valor As Char() = origen.ToCharArray
Dim numeros As Integer() = (How can i convert "valor" to an int array?????)
i have found [char] specified in some of the examples at msdn , what is the difference between char and [char]
View 2 RepliesDim r As New IO.BinaryReader(New IO.FileStream(path,IO.FileMode.Open))
While r.PeekChar() <> 0
End While
[code]......
I have a form with 12 text boxes. I'm trying to get the data from those text boxes to "save", and when that form is opened again have the data be inserted back. This form has different time slots so I need to be able to have it save and repopulate based on what time slot I am clicking on. I was going to have it read the data by splitting it with commas, then inserting them back into the correct fields but it's not working. I had it write the results to a text file and they get written correctly and inserted back, but the problem with that is it only reads that text file so every time slot I open up gets the same data.
Below is code I used to get the data when the Save button is clicked. [Code]. Problem is I get an error saying "Char values cannot be converted to Integers" on the first line, the (","c) part.
im using my method as a search method in my program and it goes like this
For Each dr As DataRow In ds.Tables("Employee").Rows
If (dr("LastName") = "GO") Then
dr(MyColumn1) = "Testing1"
[code]....
is there another way to search for a row, i think in my code it would took time because it will pass through all the rows.
I've got several methods that all need to add items to a single list which will eventually be used to populate a listview. I thought about declaring the list at class level so that all of these methods could access it, but it didnt really make sense as the only methods that access this list are Shared methods, so I didnt think it was worth having a list just sat there for the entire time that any instances of the class are created, when in a lot of cases the list would not be used.
So what I ended up doing was just declaring the list in the Shared method that then calls these other methods that need to add to the list, and for each of these methods it calls it passes the list in as an argument. The methods can then add items to the list and as the list is a reference type it updates the underlying list object, so once all of the methods have been called then the list in the calling method is up to date and can be used. Then when that method exits, the list is no longer in scope and so is removed from memory. This all works fine, but it feels a bit... wrong. Would it be better to just declare the list at Class level and not be bothered about the small overhead of the list always being in scope when instances of this class are created that will not even use the list?
EDIT: Actually, thinking about it.. because the methods that use the list are shared then the list would need to be shared as well if it was at class level - so the list would not only be around when instances of the class are created, but all of the time. So it will just be sat in memory for the lifetime of the program wont it? I assume this could make a noticeable impact on memory usage after the list has been filled with data, so I guess if I went down that route then I would have to make sure I cleared the list once I had populated the listview. This is another reason why it just seems much easier and more manageable to declare the list as a local variable in the shared method that then calls the other methods that also add to the list.
currently I am using something like the following:[code]It seems to work fine, but I've seen posts on different blogs and stuff that say string.compare is better for some reason.Is this ok to use or should I be using string.compare()?
View 3 RepliesI wrote some string extension methods in a VB assembly and am unit testing them from a C# project. However, C# acts like it cannot see the the extension methods, when other VB projects reference the VB assembly they have no problem. Both the VB assemebly and the C# test project are targeting .Net 3.5. Is there a way around this?
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Whenever we need to handle events, we do it by creating a method which handles the event. Without creating methods; is there some other ways of handling events?
View 6 Replies