I am a hobby programmer in VB.Net. Have fairly good knowledge in that. However I got stuck in a place I need help.
I have a main form called BTC_Main
I have a different class called ClientID
I would like to refer to the main form control in Client ID class file
My Line in client ID "BTC_Main.Lvw_ClientID" gives an error "Reference to a non-shared member requires an object reference"
Could anyone help me?
Thanks in Advance.
Related
i have added a service ref in my VB.NET application.
i can see the objects in the object browser. i need to log in first to obtain a session ID.
when I try
dim client as new serviceReference1.IGPSBulkData
I get an error
'New cannot be used on an interface'.
IGPSBulkdata is the only option that includes the login function so Im not sure how to make this call
any ideas?
When you add a service reference several classes are being generated from the service' WSDL. Take a closer look at the generated code 🤓 There will be something like GPSBulkDataClient.
This generated client class can be used to communicate with the service.
The error is correct; you cannot instantiate an Interface.
If you open Object Browser in Visual Studio and search for IGPSBulkData you should be presented with a list of classes which implement it. From there you can instantiate your client object (if that's what you need to do with that class).
So if there was a class called GPSBulkDataThing which implements IGPSBulkData your code might resemble:
Dim client as serviceReference1.IGPSBulkData = new GPSBulkDataThing(maybe with some arguments here)
This question has been asked many times but I can't find a solution.
I have a WCF service with a function that takes in a customer object. This customer object is in a separate project that both the client and server code reference. When I add the service reference to the client project, I choose the option to reuse data types. However, when I try to call the function on the client side and pass the customer object in, I get this error:
Error 39 Value of type 'Real.Namespace.Customer' cannot be converted to 'Service.Namespace.Customer'.
The "Real.Namespace" is the class it should be using. "Service.Namespace" is the auto generated class created by the service reference. I know this is supposed to work, so there must be some reason why it is unable to find the real class and reuse it.
I've tried this with very simple objects and it still won't work. Any ideas on why the auto generated code can't find the real class and use it?
Edit: I've tried using a very simple object just to see if I could get it to work. So right now I'm just using a test class that looks like this:
Namespace DTO
<DataContract>
Public Class Test
<DataMember>
Public Property Name As String
End Class
End Namespace
I'm working with a new Windows Phone 8 App, and trying to list the contacts on the phone.
In debug mode I can see the member Id (Contact.Id) with small blue icon next to the member (not an extension) but I can't access this member in programming mode, and can't view it when typing A = Contact.Id !, and can't find any document about it event on Microsoft site I can't find the member: microsoft.phone.userdata.contact.id
what is the type of this member?
I just realized that
contact.GetHashCode()
returns the exact same number as the Id property seen in the variable window drilldown.
Not sure how reliable it is, and how reliable it will be in the future.
Id is a private/protected/internal property of the Contact class. That means that in terms of the Silverlight runtime it's a non-accessible member. And that means you won't be able to get that value at runtime. Contact.Id is out of your reach.
Silverlight respects access levels and will only let you access members in the access level for the calling code. For example, all class can invoke all public members (properties, methods, events, fields, etc) of all other classes. As another example, only classes in the same assembly can invoke internal members of classes in the same assembly. If any class outside that assembly attempt to access internal members they'll get a MemberAccessException. And as a final example if a class declares private members (e.g. private field) then only that class can access that private members. If another class attempts to access private values inside a class it'll receive a MemberAccessException.
The above is true for both runtime (Reflection) invoked members and for compile-time (hardcoded) invoked members.
I am creating an XML web service that passes an array of custom types. In my consuming code I am referencing the code as a web reference which I have given the namespace MYWS. Now in code I am trying to assign the results of my web service call to an array of my type like so :
'instance to make a call to my web service
Dim srv As New MYDWS.ServiceNameWSSoapClient
'array to hold the results
Dim arr() As MyClass
'assign the web service call results
arr = srv.myWebMethod()
When I do this the complier complains, saying:
Value of 1 dimensional array of my.namespace.MyClass cannot be
converted to 1 dimensional array of my.namespace.MYWS.MyClass because
my.namespace.MYSW.MyClass is not derived from my.namespace.MyClass
Now I understand the message, the thing is they are the same class. The class is declared in my calling code by the web service references a dll from that project. How do I tell the compiler that these are the same type? Any help would be very much appreciated. Thanks!
The upshot is that you have a namespace mismatch. If you right-click on MyClass in your example and select Go To Definition, where does it take you? I suspect that you may end up in a locally defined class.
The solution is to change
Dim arr() As MyClass
to
Dim arr() As MYWS.MyClass
Update based on information in comments
The problem with using the web service is that you cannot cast it to a local class.
You have a couple of options depending on exactly what you need out of the local class.
If you only need methods to act on the data in the class or you need additional properties, you can create a partial class in your environment that extends the class created by the web service. For example:
Namespace MYWS
Public Partial Class MyClass
Public Property SomeAdditionalData As String
Public Sub SomeMethod
' Perform some operations on the class members
End Sub
End Class
End Namespace
However, if you have calculations or other work embedded in the class, then you will need to get the data using the web service class, then copy the data from that class into your local class. If the properties have the same names, you could ease this task using reflection.
As another option, if you have control over the web service, you could change it to a WCF service. This will allow you to reuse the exact same class code on both ends of the communication pipe.
Found a solution to the problem. In the web.config I found this:
<add key="net.mydom.mydom" value="http://localhost:7452/dir/mysvc.asmx"/>
which was what the system automatically entered when I registered the web service. I got the error messages on screen, but everything compiled and ran w/o problem.
When I manually changed to this:
<add key="net.mydom" value="http://localhost:7452/dir/mysvc.asmx"/>
The error messages went away and everything continued to function as expected.
(That only took my 7 years to figure out...)
UPDATE:
Well, not quite the fix, but it must be close. After awhile, the problem came back, when I switched back to to:
<add key="net.mydom.mydom" value="http://localhost:7452/dir/mysvc.asmx"/>
it went away again...sure to come back at any time...
UPDATE
If I explicitly add:
imports net.mydom
to the top of my code, the message goes away again (even though I was explicitly using the full net.mydom. when typing the variables.
I'm redesigning an old VB6 application into VB.net and there is one thing I'm not sure on the best way to do.
In the VB6 application whenever we created a new instance of a component, we would pass in the user details (user name and the like) so we new who was performing the tasks. However, no that I'm redesigning I've created some nice class designs, but I'm having to add in user details into every class and it just looks wrong.
Is there a VB.net way of doing this so my classes can just have class specific details? Some way so that if my classes need to know who is performing a task, they can get the information themselves, rather than having it passed in whenever the objects are created?
You could put the details of the current user in a class that is accessible by all class instances of your application.
One place you could consider putting it is in the MyApplication class. You could also create a module and place it there.
Could you wrap the current user details into an object, and pass the object when you create the others? They would just keep a reference, and delegate to the user object for user-specific stuff.
That seems like the obvious way?