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]...
explain 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 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 don't understand the error, Argument not specified for parameter 'test' of 'Public Shared Function TestThis(test As String)'.
Partial Public Class Form1
Shared Sub ReceiveCallback(ByVal ar As IAsyncResult)
Form1.Invoke(TestThis, New Object(){"test"}) 'error
[code].....
I can access a module from code behind but not from the aspx page in inline VB code <% ... %>.
View 2 RepliesI 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.
if you could see everthing but the thing I'm having trouble with the Public Shared Function(folder in 'Dim folder As nvironment.SpecialFolder' is the problem)
Option Explicit On
Option Strict On
Imports System.IO
[code].....
I've taken over the maintenance of the website (ASP.NET VB) and on one particular page I noticed the below code
Inherits System.Web.UI.Page
Public Shared UserNumber As String
Private Sub Page_Init(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Init
[Code]....
My question is whether the variable UserNumber can be accessed or changed by any other user than the current one?
I want to know what implies to declare a function or a sub using public or directly Sub / Function i.e.:
Public Function Whatever()
' Process
End Function
versus.
Function Whatever()
' Process
End Function
I have an arraylist in a user form (Mainform) that I would like to be able to share among multiple forms and edit the contents. Using the Public Shared method I have been able to view and even edit the arraylist, but it does not seem to be changing it back on the main form. I can give more detail if needed.
View 9 RepliesSay I have an ASP solution with a Globals.vb file. Inside that file, I have this: Public Shared MyVariable As String Now say I publish this solution and make it available to Bob and Cindy.If Cindy sets (through the interface) MyVariable to 5, would Bob be able to read it? I hope not, I'm hoping this variable would be user-specific.
View 2 RepliesI currently have two forms, and I need to share the value of a variable in one of them.
I declared the variable to be 'Public Shared', and assigned a value to it. However,
when I inspect the value it appears as 'Nothing'. Here is the snippet:
Public Class A
Public Shared sVar As String = Nothing
Private Sub A_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
[Code]....
I have created a public shared subroutine in a class file in asp.net 2 (vb.net) web site app_folder.The subroutine retrives some values from a sql database via an sql query and assigns the datareader field values to several variables The problem is I can't seem to assign the variables from the subroutine to the variables and textbox controls in the asp.net page I am calling the subroutine from. The textbox text value just appear blank.By the way, if I response.write the variables in the subroutine they appear populated by the sql data reader.
View 9 RepliesI have an asp.net web app. It has a shared class, and I want to have the connection string the same through out the site. My string is in my web config, but I don't want to type this all over the place:
View 3 Repliesgive me a good resource that explains the difference between a Private, Public, Shared Functions/Sub/Variables? I normally use Public for Subs/Functions inside of Modules I call from other parts of the program. But I'd like to get more of an understanding of how and when to use them. I want as little as impact to a system that is running my programs as possible, so i guess the key here is I'm trying to just get more proficient in my coding.
View 8 RepliesCan we override a Public Shared method in derived class? If not why?
View 2 RepliesI have a List(Of AddlInfo) with AddlInfo being an object. I'm trying to pass addlInfoList by reference into a function of another class:
[Code]...
This works if I'm not passing the reference into another class, but when I try to do this, I get the following error: Overload resolution failed because no accessible 'Sort' can be called with these arguments:
[Code]...
shared variables of particular form in vb.net 2005
View 1 RepliesI didn't write the function for the AutoCompleteExtender so I am not quite sure how to change it without screwing it up, so I figured I would ask here. Recently, it was requested that the AutoComplete show a product name & the date of launch of that specific product. I do not know how to add the date to the AutoComplete.
View 1 RepliesI am trying to get a handle on SyncLock and multithreading, but I am having some trouble wrapping my head around exactly how it should be implemented. I have a Public Class Utilities with a many Shared Functions. I want to make sure that each function can only be executed when there are no other concurrent calls to the same function. So If I have 2 functions, A and B in a Public Class Utilities, what is the syntax so that a function "locks" while it is being executed, preventing any subsequent calls until the "locking" thread has completed?
CODE
Public Class Utilities
Public Shared Function A (ByRef i As Integer) As Integer
[CODE].............................
I know I need to wrap the statements of execution in a SyncLock block, but I am unsure of the scope of the parameter used with SyncLock...is it private to the function, class, etc? Can the same object be used to lock both functions if they are independent?
I am just testing how to use dll and after googling a lot, I made it work partially...Created new project Class Library, named it myFirstDll and made a Public Shared Sub helloDll to do something. Now since this is my first time, the dll is simply showing the input in a msgbox:
Public Shared Sub helloDll(ByVal msg As String)
If msg <> "" Then
MsgBox(msg, MsgBoxStyle.OkOnly, "WE HAVE SOME MSG")
Else
MsgBox(msg, MsgBoxStyle.OkOnly, "NO MSG")
End If
End Sub
After building the dll-file, I started a new project using normal windows forms, named it "useMyDll", I clicked Project -> Add Reference, and added my dll. The program file that I made needed a textbox and a button for using the dll:
Private Sub useDllButton1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles useDllButton1.Click
Dim msg As String = Nothing
msg = TextBox1.Text
myFirstDll.myFirstDLL.helloDll(msg) 'this will be in msgbox in dll-file
End Sub
And when running this I could write something in the textbox and a msgbox with that input would pop up. Really happy with that. My first attempt to make a dll and use it was very successful. Then I thought, what about running the dll from rundll32.exe? It would be handy to make a dll that could be run without my exe. After googling a long time, I tried to add a new button:
Private Sub useDllButton2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles useDllButton2.Click
'Now let us see if we can open it using rundll32.exe ?
Dim msg As String = Nothing
msg = TextBox1.Text
[CODE]...
Now the first button still works just fine, but the second button gives some error (translated to english would be) like "missing entry: helloDll" I also tried to open with command prompt, same result.
After googling again I read one place that you can't run a visual basic dll with rundll32.exe, so is this true? Or is there some way of doing it? I read one place that it works if you make the dll be "COM-Visible", but I don't really understand how to or what it means. I tried to open properties, clicked Assembly Information, and "Make assembly COM-Visible", but this doesn't change anything. Then I read somewhere that it has to be in a module to work. Could it be that I need to rewrite some codes and it would work, or would I have to start learning c++ in order to accomplish this?
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]....
I have a public function to call default email client.Public Function OpenEmail(ByVal EmailAddress As String, Optional ByVal Subject As String = "", Optional ByVal Body As String = "") As Boolean
[Code]...
I have a public function to call default email client.
Public Function OpenEmail(ByVal EmailAddress As String, Optional ByVal Subject As String = "", Optional ByVal Body As String = "") As Boolean
Dim bAns As Boolean = True
[code].....
Here's what i would like to know, i will post my layout below.
CODE:
Right what i want to do is when i click my button it goes to the timer3.tick.. i then want it to use the public function on the listbox's.
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()
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)..
xplain to me or give me an example of using a select case in a shared function
View 2 Replies