i am beginner about general programming. Please give me basic shared functions .
I only know few functions such as : Public Shared Function lon(ByVal a As Integer, ByVal c As Integer) As String Public Shared Sub trung()
in the old days i could so something like
GWBasic
10 A$="ReallyLongStringInSmallSpace": B$="tiny"
20 PRINT USING" ASDFASDFASDF ASDFASDF"; A$; B$
Output:
"Re ASDFASDFASDF tiny ASDFASDF"
it would automatically truncate large strings to fit in a small assigned space, and it would use empty spaces for strings too short. it made it VERY easy to print fixed front text tables in aligned columns by automatically truncating long lines and expanding using spaces (chr 32) where needed.i've already looked at .Format but it seems just for dates, times, currencies, and various byte/hex formats.
NetShareAdd API from a VB.NET application (.NET version 2.0) and although I can get the API to just create a basic shared folder I now want to create a shared folder and specify its Share permissions (not NTFS permissions) as well, which means I have to pass in a SHARE_INFO_502 structure rather than just a SHARE_INFO_2 like I was previously doing for creating a basic share. I have spent over 5 hours solid just trying to get this working and am getting to the point now where I really cant think of anything else to try.I've encountered several problems whilst trying to make this work but the one I am finally stuck on is this: When I call NetShareAdd it returns the error INVALID_PARAMETER and the parm_ err object (which is supposed to specify which member of the SHARE_INFO_502 structure caused the error) holds the value 501. I know it is something to do with the security descriptor because if I comment out the line where I set the SHARE_INFO_502 structure's shi502_ security_descriptor field then the code works without an error (just obviously does not set the share permissons I want).I think posting all of the code here might be a bad idea as its currently over 150 lines long (yes that is only code for getting this API working...) so I'll just post my definitions of the SECURITY_DESCRIPTOR structure and the code I am actually using to call the various APIs involved: [code] Each of those API calls prior to NetShareAdd returns a non-error value in the Debug.WriteLine that is done after each one, but there is obviously an issue somewhere with the security descriptor.
View 2 RepliesI have a class, MyClass, declared as public, with a Shared method test():
[Code]...
If I comment out Response.Write MyClass.test(), everything works fine and I can use the Class - however, trying to access the Shared method, I get the following error: Local variable 'myClass' cannot be referred to before it is declared Any pointers as to what I am doing wrong?
What does this error mean in VB6? Function or interface marked as restricted, or the function uses an Automation type not supported in Visual Basic.
I keep getting it when i call a particular method of a dll that comes with windows xp and beyond (in system32 called upnp.dll)
i have a function that i have in my data access class now i want to access it then declare and assign parameters and then insert data into database?
'1
'the function
Public Shared Function InsertNewRecord(ByVal myStoredProcedure As String) As Boolean
Dim conn As New SqlConnection
[code]....
VB.NET 2010, .NET 4. I am working on an application for controlling an industrial machine composed of many devices attached to the computer. Most if it is reasonable straight forward, but I'm having trouble thinking about the RS-232 devices. One of the RS-232 devices is a fancy power supply with many functions. The ones that are relevant right now are voltage read, voltage write, current read, and current write. The design pattern I'm trying to implement is one in which each attached device is represented by an object that has methods for reading/writing etc and properties for things like COM port etc.
For this power supply, clearly the Port reference should be shared among the instances, so I have a base class (say, PowerSupply) with a Protected Shared Property Port As IO.Ports.SerialPort. Then I have a couple classes that inherit from this class, PowerSupplyVoltage and PowerSupplyCurrent that each define read/write methods and properties for holding the last read/written values. My issue is in parsing the response from the power supply using the Port.DataRecieved event on the shared SerialPort object. The protocol the power supply uses specifies what data it's sending in each response packet.
So, basically, it might say something equivalent to "The voltage is 100V" or "The current is 1A" or "The voltage has been set to 150V" etc. I'm trying to parse this in a shared function. Only during the parsing process would I determine which instance's read/written value to update. I can't access the read/written value properties of the instances from within the shared function. The best I could think of is creating some kind of PowerSupplyCommunicator object that would maintain references to PowerSupplyVoltage and PowerSupplyCurrent instances along with the shared Port and DataRecievedHandler functions.
how I can dynamically load a control inside of a shared/static function?The function itself is inside of a mustinherit/abstract class.(It's an ASP.NET project in VB) I want to do something like this:[code]I'm getting "Cannot refer to an instance member of a class from within a shared method or shared member initializer without an explicit instance of the class.",but I don't understand this error.I understand what it means, I just don't understand why calling LoadControl isn't seen by the compiler as being an explicit instance of the class. What's not explicit about using LoadControl to create a new control from a file? I tried creating a new user control and initializing it, then setting it to a different control with LoadControl to no avail.I also don't want to do a DirectCast because I'm trying to put this in a shared, mustinheret (abstract) class, which therefore doesn't have an .aspx file to write in a <%@ Reference Control="~/SomeControlPath.ascx" %>, so the class name is unavailable.What I'm trying to do is write a static function that takes some value and returns a control based only on that control's source file location.The end result is a user-modifiable list of controls.They get a column of controls that they freely add, remove, or reorder based on a static list of available child controls that I specify.
View 4 RepliesI 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 made the changes from this:
[code]...
to this:(the 'End Function' says "Function 'GetFolderPath' doesn't return a value on all code paths. A null reference exception could occur at run time when the result is used."
[code]...
xplain to me or give me an example of using a select case in a shared function
View 2 RepliesWhat's the advantage of declaring a function as "Shared"? I've noticed that it doesn't require you to instantiate an object to use the method when it declared as "Shared". Is that the only upside?
View 3 Replies[Code]...
i have a function that i have in my data access class now i want to access it then declare and assign parameters and then insert data into database.
I get this error: Cannot refer to an instance member of a class from within a shared method or shared member initializer without an explicit instance of the class.
Partial Class _Default
Inherits System.Web.UI.Page
<WebMethod()> _
[Code]....
I know it has something to do with the fact that the first function is shared and the second function should probably be Public as well but I don't fully understand the reason behind it. Probably not relevant but I'm calling the web method from some javascript.
I have as sub that is triggered from the file system watcher when the new file is created in spec. directory.I need to call some function to do something with that file. [code]
View 6 Repliesi created a dll file using vb.net then it has a shared function that will execute a stored procedure of mysql but my code is something long and when accessing it, it has a big risk that it can produce an error if there is an incorrect string input, i am asking an advice how i can make it much better or can point me something much better than my code as my reference.here is my codefirst i created a function named mysqlParamDatatype wiith 1 parameter, this function will detect the mysqldatatype of the mysql sproc parameter so it can pass the value with the correct datatype. but it is to long.
Shared Function mysqlParamDataType(ByVal i As Integer) As MySqlDbType
If i = 1 Then
Return MySqlDbType.Binary
[code].....
Consider I have a shared function:Public Shared Function CalculateAreaFromRadius(ByVal radius As Double) As Double
[Code]...
If I have two or more threads in the same vb .net app and each of them calls the shared function at the same time with different RADIUS, will they each get their own AREA? I want to know for each call to the function if it is using same local variables or each call creates new instances of local variables?Will the answers to above questions be same If I have multiple (2+) single threaded apps and they all call the function at the same time with different RADIUS value?
Im having a problem understanding if accessing httpcontext inside a shared function, without passing in the httpcontext as a parameter is thread safe?
Are the 2 functions in the util class equally thread safe?
Class foo
Sub main()
Dim qs1 = util.getQS(HttpContext.Current)
[Code]....
I had a problem (which is now fixed) but I've no idea why.I have an Ajax AutoCompleteExtender with a WebService method to populate like <WebMethod()> _
Public Shared Function populateACE(prefixText As String) As List(Of String) However this didn't work - I put a breakpoint in, and it didn't even get hit. However... <WebMethod()> _ Public Function populateACE(prefixText As String) As List(Of String) does work (the only difference being not Shared).
Fair enough, but why? If you have an instance of a class then you can access Shared methods of it; if you don't have an instance of a class then you can access Shared methods of it. So what is going on behind the scenes?
I'm trying to get a query string from a shared function in a code-behind model using VB.NET. You have to use HttpContext.Current.Request.QueryString("Query") in order to get it from a shared function, however doing HttpContext.Current.Request.QueryString.Count gives back 0, which obviously isn't right in my case as there's many that exist. Is there some sort of issue with using this static call from a shared function?
View 1 Replieshow to pass system.type or a generic without much luck. I have two functions below one that works and the other that doesn't. I can't seem to make heads or tails of the VB syntax required for doing what I want to do.
' This function does not
'
' Also attempted it like this
' Public Shared Function UnserializeFromJSON(ByVal obj As String, ByRef ty As System.type)[code].......
The context of this question is that I am trying to debug performance issues (apart from the obvious ones I already know about and can find).I inherited a code base (VB.NET) for an ASP.NET app. This is an app that was developed way back in .NET 1.1 days, and was the first .NET app for a lot of the developers who worked on it.
In this code base is a class called DatabaseUtility that contains several Shared Public methods as well as non-Shared Public Functions and Subs for CRUD operations to the database (SQL Server).
It is common in my "BL" that a method creates an instance of the DatabaseUtility which essentially figures out what the connection string should be and opens a connection, as well as giving the developer a handle to the other methods contained within it.Dim utility as New DatabaseUtility()
Once I have that, I start to create parameters that I am going to pass to one of the methods in DatabaseUtility (like GetDataSet). There is a Shared method in my DatabaseUtility called CreateParameter which does essentially that. It creates a SqlParameter object so I can add it to a Parameters collection.
Now, the code base is littered with a lot of this:
utility.CreateParameter(...)However, because CreateParameter is a Shared method, I am not sure what is going on behind the scenes. I know because it is a Shared member that an instance of the DatabaseUtility is not created when I call it like this:DatabaseUtility.CreateParameter(...)
However, because I am calling it from an instance (utility), does that change the behavior at all?
Here is a VB.NET Console module I'm testing to understand how Multi-Threading/Threads work.
Imports System
Imports System.Threading
Module Module1
Public Class SimpleThread
Public Sub SimpleMethod()
[Code]...
With the help of NetFileEnum or Openfiles.exe of system32, we can get the username who has opened the shared files. Is there any API function or any exe files in any programming language like c#, vb.net, visual c++ to find out who is the user to create, rename, or delete shared files or folders on the network?
View 1 RepliesWhen I find examples online of VB.NET watch some functions use:
(Protected / Partial) & (Friend / Shared) & (Sub / Function) exp()
End (Sub / Function)
what is the difference?
i would like to have a shared function in a separate class file to address the form location . but i dont know how can i get this to work. if i use this below code in my form its working . but i cannot move this to a class file.
Shared Sub Formlocation()
Me.StartPosition = FormStartPosition.Manual
Me.Location = Screen.GetWorkingArea(Me).Location
End Sub
If I have two threads both calling a normal function at the same that appends strings, sometime the output string is a combination from both threads as the function had not finished executing the code before it was called again... Would a shared function wait to finish first?
View 9 Repliesexplain me the difference between them? I'm new to visual basic, and I need to know the very basic things in Visual Basic allowing me to become a professional User
View 8 RepliesIs there a simple sleep function in Visual Basic that doens't involve thread.
Something similiar like there exists in: C: sleep(1);
We also tried this code:Declare Sub Sleep Lib "kernel32" (ByVal milliseconds As Long)' pause for 5 seconds
Sleep 5000 but it didn't work. It gave me this error: PInvokeStackImbalance was detected
[Code]...
I must say I don't get the vb Random function. Try making a basic winapp application, but a button named Button1 and a few (around 10) labels on the form. Then add the following to the forms codebehind:
Code:
Public Class Form1
Public Function RollDize(ByVal iDize As Integer) As Integer
Dim iRes As Integer
[CODE]...
Now, if you click the button, you will see that all the labels get the same number. However, if you step through the code in debug, the numbers are random.