I have a custom class called "Time" with the following function, for determining if one Time equals another Time.
Public Shared Shadows Function Equals(ByVal Time1 As Time, ByVal Time2 As Time) As Boolean
Dim x(2) As Integer
x(0) = CInt(Time1.Hour)
x(1) = CInt(Time1.Minute)
[code].....
Access of shared member, constant member, enum member or nested type through an instance; qualifying expression will not be evaluated.I know it shouldn't do any harm, just let the compiler skip evaluation, but is it a way of getting rid of this warning?
In the following code i get a warning at line 59:Warning 1: Access of shared member, constant member, enum member or nested type through an instance; qualifying expression will not be evaluated.and.. At line 78 I get this Warning:
Warning 2 Property 'SelectedCustomer' doesn't return a value on all code paths. A null reference exception could occur at run time when the result is used.
The program compiles and runs well, but i cant' undesrtand the reason for these warnings. Any Idea ?
1: Public Class Form1 2: 3: 'Form level members 4: Private objCustomers As New ArrayList
Cannot appear to be able to get this function to not have the above error.Private Function GetIncidentActions(ByVal FromAgentID As Integer, ByVal ToAgentID As Integer, ByVal incidentAction As Integer, ByVal ActionDate As Date) As String
i changed a class variable to shared so i can access it in all instances of the class, but it caused an error. what is causing this, and how can i fix it?
We have a coding standard that says all shared (static) fields and methods must be called with the class name. E.g. NameOfClass.whatever Is there a tool that we can use to check this is in fact the case? (Likewise for modules) I should have make it clearer we are using VB.NET.
And is this an good example of a member that should be shared? If so does both the Private and the Public need to be shared. I just started using Refactor Pro and it almost always is recommending that I make all members shared. Is there ever a good reason not to do so?
I have a bunch of classes that all contain a Shared ReadOnly Dictionary. If I want to access that Dictionary when the class is a generic type (such as when I have a wrapper function that takes T as an interface that all of these classes implement), what's the way to do it?
I want to do something like GetType(T).GetMember("Dict"), but that will return a MemberInfo type, and that cannot be cast to a Dictionary of my defined type(s). For calling functions this way, one can use a delegate + CreateDelegate + GetMethod. But there doesn't seem to be an equivalent Create*for GetMember stuff. Or am I missing something?
If I plug the GetMember call into the immediate window, and then use a subscript as if it is an array, then the debug output says I am getting a Dictionary back. But if I use that same approach in the actual function that I am trying to write, then I get an error about System.Reflection.MemberInfo cannot be converted to Dictionary(X, Y)
I would like to understand the Pro & Cons in using the commonly used methods via Singleton class against Shared (Static) members of a class in VB.Net. It could be in terms Time, Space complexity or best practices. I have a BankAccount class with methods doing some business logic.
I've used .NET for a long time but I've never really been sure of this warning :-"Access of a shared member, constant member, enum member or nested type through an instance; qualifying expression will not be evaluated"Whilst this is not causing an issue and I've not really experienced this problem a lot with my own code, converting some code from an old .NET project gives 10's of these errors.
Code: Protected Function GetContentTypeFromString(ByVal TypeString As String) As MailContentType Select Case TypeString.ToLower
After I formatted my laptop and reinstalled Visual Studio 2005, I receive a lot of same error as below message. "Access of shared member through an instance; qualifying expression will not be evaluated" If I click the error, it direct me to the line and all 102 error suggest me to add "Windows.Forms." before "DialogResult.OK". Should I add something on "Reference"?
I created an enumeration in a class library... and compiled it into a dll
Public Enum TestEnum x = 0 End Enum
I then imported this reference to a windows form project as a referenced dll Public Class Form1 Dim mytestenum As TestPublicEnum.TestEnum Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
I'm a newbie to threading, trying to learn it as I go. don't make any assumptions and try to explain threading concepts and rules that might seem obvious. I have a Module (Static class) as follows:
Module Main Private ReadOnly _dbConn As SqlClient.SqlConnection Public ReadOnly Property DBConn() As SqlClient.SqlConnection Get Debug.Print("Accessing DBConn")
[Code]...
All throughout the application, when i access DBConn on the same thread, it works as expected. howeve, later on I created a background worker that tries to access DBConn and nothing happens, the thread just hanges (the Background worker). I dont get the printout and the application doesnt continue. the background worker thread doesnt continue past that point, and so the thread never exits. I dont get any exceptions, and i Cant debug in Visual Studio (visual studio hangs).I guess its a 2 part question: why cant i access DBConn from the other thread, and why does it hang without giving me a threadAccess exception? also, why does visual studio hang (I'm assuming it hanges because the thread is hanging)?
Please Note: I am not asking about practice. I know I shouldnt be sharing the same connection, rather returning a new connection. in this particular application it is safe since (although i execute it on a background thread) as per the flow of the application, the connection can only be accessed one at a time. I just want to know why it hangs accross the thread.
re: Access of shared member constant member enum member or nested type through an instance qualifying expression may not be evaluated I understand that this warning means that you should not reference a shared member via an instance. However, in my test case Test2.t.x("3"), I don't understand why it thinks I'm using an instance, since t is also a shared member. Also, note Test3. See what happens when you change declaration of GetObject() As Object to As Test3. I think I understand the behavior (not eval'd until runtime)
Public Shared Function MyValue() As Integer Return 0 End Function Public Sub Code()
[Code]...
Me.MyValue gives a warning in VB.NET and (the equivalent code gives) an error in C#. Is there a particular reason for this? I find it more intuitive/natural to access the shared function using 'Me.MyValue' - but I avoid it to keep my warnings at 0. Did someone else just decide 'Nah, it makes more sense to do it the other way' or is there some technical reason I don't understand?
EDIT: I was thinking of it wrong, more like a 'sub class' in OOP. Even if something is declared in the base class, you access it through the instance you have. But that relationship is not the same with shared or static.
I've encountered a problem which challenges my understanding of access modifiers in VB.Net. I have a class declared Friend. If I declare its properties Public, the application works. If I declare them Friend, the application fails.
Before this, I believed that, in a class declared Friend, it would make no functional difference whether I declared the members Public or Friend. I thought class access declarations applied their restrictions to all nested entities, so nested properties declared Public were effectively restricted as if they had been declared Friend. Obviously, I was wrong. Can anyone explain how access modifiers really work, or point me to the relevant documentation?
Here is a more detailed description of the situation: I have a Friend class called StripTask with properties called StripDate, HistorianDate, and TaskText. I have a collection of StripTasks (called _StripTasks) which is used as the data source for a Syncfusion GridDataBoundGrid. The way the binding works, I need to pass the name of a StripTask property to each of the grid columns so each column knows what data to display. It ends up looking something like this:_DataBoundGrid.GridBoundColumns(1).MappingName = "StripDate". When the mapped properties are declared Public, it works. When the mapped properties are declared Friend, the grid is populated with the correct number of rows, but every cell is empty.
As a follow-up question, is it a good idea to avoid things, such as this Syncfusion binding method, which require me to pass property names as strings? It just feels as if I'm inviting trouble.
I am making a small application in which i have added a class module and a window forms in vb.net. i want to acess the shared variables and mathods of class without making any object.
I am trying to add shared members in derived classes and use that values in base classes...
I have base
class DBLayer public shared function GetDetail(byval UIN as integer) dim StrSql = string.format("select * from {0} where uin = {1}", tablename, uin) end function end class
[Code]..
currently there is error using the tablename variable of derived class in base class but i want to use it i dun know other techniques if other solutions are better then u can post it or u can say how can i make it work? confused...
Inside my .aspx I have some JSON code that looks like this:
[Code]....
Basically what I'm doing is pulling text from two labels on one page, and sending them to another page by calling the "doIt" function which looks like this:
[Code]....
Just so I'm clear, the "doIt" function and the JSON call are on two separate web forms. My problem is that with the "doIt" function being Shared, I can't access any global variables of the class. And if I remove the Shared, my JSON doesn't execute.
Just asking for personal preferences, pros,cons on the following situation. I have a class(classA) that has some shared members in it. I have a procedure in a form that needs to execute a function in a separate class(classB). This function requires some of the shared member values from classA. I can either pass these values as parameters from the form to classB, or in classB I can just access them directly by referencing classA. As a general rule I've tended to try to use parameters to pass all the information a function needs but it starts to seem a little unwieldly when passing several parameters to multiple procedures.
Ive put in some code to trap a keystroke... In this case, a spacebar.If I call somethingsiple like application.exit(), no problem.I do need to have it call a local public sub though, and when I do so, I get the error: "Reference to non-shared member requires an object reference"I've tried to research this, but what the forums are saying to do is not clear to me yet.[code]The forums are saying to declare the sub as a class and call it as a variable.
I'm attempting to use a function which exists in a class (IDautomation.vb) I found online.I use the "Imports" statement at the top of my class/form. When I attempt to call a function from the Imported class I get an intellisense error:
"Reference to a non-shared member requires an object reference" I guess I thought by using the "Imports" statement I could access any of the properties/methos from that class.
I have added a settings file to a project but whenever I reference one of the setting variables I get the following error:
Error 2 Reference to a non-shared member requires an object reference. C:DevelopmentPhoenixAppProcessCreditCardProcessing.vb 67 77 Process
I had to manually add this in a merge conflict and the settings code worked fine in the originating branch. The generated code also seems to be identical from what I can see.
I am accessing the settings using My.Settings.{VarName}
edit: Just tried deleting the settings files. This still happens once the file has been re-generated from the app.config values.
Is it considered an acceptable practice to use Modules instead of Classes with Shared member functions in VB.Net?I tend to avoid Modules, because they feel like left over remains from VB6 and don't really seem to fit in anymore. On the other hand, there doesn't seem to be much difference between using a Module and a Class with only Shared members.
I've got an project that whenever an exception is throw will generate an error log. It was debugging fine so I decided to build a test version to let some co-workers try out. The build didn't work exactly right and I had to alter some reference properties to get it to build. Now I have the following error, "Reference to a non-shared member requires an object reference."The red highlighted text shows "reference to a non-shared member requires an object reference.
