I want to invoke a method on a class that i have a reference to. The method that I want to call has a custom attributes. Currently I can find this attributes and call the property of my class Attribute.
is there a way to invoke that method ?
PS/ The project is written in vbnet, but I think the solution is the same in c#.
Imports System.Threading Public Class TestClass Private myClassThread As New Thread(AddressOf StartMyClassThread)
[code]....
The result:Application runs, no errors or exceptions.Displayed is the listbox and the Start button.I press the start button and a msgbox says "Not Invoked" as expected and upon clicking OK to that msgbox "Start Button Pressed" is added to the Output listbox control.Immediately following that the msgbox pops up again and says "Not Invoked". I was expecting "Invoked" as a separate thread is trying to use the Output listbox control.Of course this results in the Output.Items.Add being attempted which results in no visible result as the thread is not allowed to directly update the UI control.
I have been using a pretty slick generic invoke method for UI updating from background threads. I forget where I copied it from (converted it to VB.NET from C#), but here it is: Public Sub InvokeControl(Of T As Control)(ByVal Control As t, ByVal Action As Action(Of t))
Consider a MyForm class that contains a shadowed implementation of Show(). It also contains a CreateForm() method, which accepts an instance of the form and calls the shadowed sub:
1. On the main form a scanner class is instantiated that (in the scanner's constructor) sets the scanner settings (baud rate, parity, etc) and opens the scanner for use
2. A barcode is scanned (via a scanner connected to the device in a seral port) while on the main form
3. In the scanner class, the DataRecieved event gets the needed info from the scanned code.
4. Then that info is passed back to the main form to a method RunCommandCode (which takes the scanned info as an argument)
5. On the main form the RunCommandCode calls another method CommandCodeHandler, passing the scanned info again
6. In the CommandCodeHandler sub a method is called in a Utils class (SetSelectedTab), which interacts with the form itself (determines how many tabs exist on a tab control), which is the reason for the invoke in the first place
So, before I figured out I needed to use the Invoke method (and, more specifically, that the scanner was working in a different thread), I was getting an error in step 6 on the line that got the TabControl.TabPages.Count.
I am implementing a custom iDispatchLLInvoke handler for VB.NET - some of this is working.So Far - I have been able to intercept and provide custom handling of simple functions and property calls - but I am stuck when I try to set a property and get an error "Invalid Pointer (Exception from HRESULT: 0x80004003 (E_Pointer))".
I am using the new .NET 4.0 ICustomQueryInterface to do this. In Summary - I intercept and provide my own implementation of iDispatch - I load the dispIDs on the first call - and return a the dispID for each call within GetIDsOfNames - this ID is than passed to Invoke where reflection is used to get the value and return the result.
When I attempt to set a property - a call is made to GetIDsofNames and I return a valid dispID - the application than crashes with the error above and no call is made to Invoke.As a result - I am assuming that the issue relates to my interface definition been wrong becase the code never get's back to .NET code - see below for this code:
<ComImport(), Guid("00020400-0000-0000-C000-000000000046"), InterfaceTypeAttribute(ComInterfaceType.InterfaceIsIUnknown)> _ Public Interface IDispatch Sub GetTypeInfoCount(ByRef pctInfo As UInt32)
I've created a MyFunc extension (in Module Extensions) for all the base types as well as generic arrays, ICollection(Of T) and Dictionary(Of String,T):
Function MyFunc(Of T)(a() As T) As String Function MyFunc(Of T)(collection As ICollection(Of T)) As String Function MyFunc(Of T)(dict As Dictionary(Of String,T)) As String
What's the difference between using the in out attributes in a interop method call such as SomeWIN32APICall(<[In],Out> Byval SomeVariable as SomeType) Vs SomeWin32APICall(ByRef SomeVariable as SomeType)? When I use the latter my app crashes.Edit: Fixed Typo
Is it possible to somehow invoke foo("SomeAwesomeString") from VBScript directly (i.e., without it having to launch an additional process)?
The use case is this: I am trying to write an 'extension' application for hMailServer (hMS), but hMS can only invoke VBscript scripts when an event happened. I can have the VBscript launch an .exe every time the event happened, but the processing involve opening and closing a connection to a back-end database. So, every invocation is very expensive. I had been thinking that I can reduce the expense by having a Service to maintain the connection (i.e., opening it once and re-open it if the connection closed). Plus by implementing the processing as background worker threads will result in a non-blocking processing + less process-starting overhead.
I have a COM component that I want to call using late-binding from VB.NET (using Primary Interop Assembly - PIA method). My IDL signature for the COM method looks like: HRESULT Send([in]BSTR bstrRequestData, [out]VARIANT *pvbstrResponseData, [out]VARIANT *pvnExtCompCode, [out,retval]int *pnCompletionCode);
So 2 'ByRef' parameters in VB.NET lingo, and a return value. I attempt to invoke this method like so: Dim parameters(2) As Object parameters(0) = "data" parameters(1) = New Object() parameters(2) = New Object() Dim p As New ParameterModifier(3) [Code] ..... This fails spectactularly with an exception: {"Invalid callee. (Exception from HRESULT: 0x80020010 (DISP_E_BADCALLEE))"}
I assume this means I'm doing something wrong in my parameterMods array. Because if I comment out setting any value of the ParameterMods array to 'True' - it works. It of course doesnt update the parameters that are [out] parameters and so it's not working as intended. Is there something else to consider since the method also has a return value? The MSDN example pretty much does exactly what I am doing, with the exception that example did not have a return value.
I Have a Function on my frmMain Class wich will update my control to something else after an invoke. When i type "?Label1.Text" on the Immediate Window, the text property IS updated, but when i go check the Form, nothing happened. The code is just like this
I have a ASP.NET (C#) web page which utilizes a VB class library. The VB library performs a SOAP POST to a remote web service and returns a message. However the VB library keeps running into a "No connection could be made because the target machine actively refused it xxx.xxx.xxx.xxx" However, I've also created a C# test client which consumes the same VB class library and can perform the post just fine! [code]
I have written a class that handles my socket information, which means i need to raise events back to my form class using a delegate. But for some reason the following does not work: -
Public Class Form1 Private WithEvents objEthernet As Ethernet Dim Eth As New Ethernet
[Code]....
Both of the Disconnected and connected events fire and are working from my socket thread but when i call "CallPassData" i get the following error "Invoke or BeginInvoke cannot be called on a control until the window handle has been created"
The problem is that, when I call the "SetStatusBarText" sub from another thread, InvokeRequired is True (as it should be), but then my threads stall on the Me.Invoke statement - pausing execution shows them all just sitting there, not actually invoking anything.
I am new to making events and I have read up on them to further my understanding of them, and I have come across a situation that I am stuck at. Currently I have a handful of classes (lets call them a childform) that are all inherited from a class that's a form (lets call it a parentform) with an event called UpdateData(). When these forms are created they are added into a hashtable of ParentForms then added into another form. I call on these forms through a method that returns the form from the hastable. [code]....
How can we apply attributes to class fucntion using AOP in C#?I am slightly not clear in what context AOP should be used? As we can use AOP for logging purpose, security(Authentication), please suggest some other scenarios where we can take benefit of AOP.Is AOP can be use to share data among different running threads in application process?
VB.NET allows you to set optional parameters like this to avoid order restrictions (which is lovely) but in this case it's forcing you to that.For example this is not possible:
<TestAttr("a", "abc", "foo", 3)>
even though the parameters are in the same order as the original definition.
I have an API that I created and currently utilize successfully in C#. I am trying to create an example of interacting with the API in VB.NET (so that the QA without C# experience can still utilize it for creating automated tests).
In C# I do the following
[TestingForm(FormName= "Land Lines", CaseType= _caseType , Application= ApplicationNameCodes.WinRDECode, HasActions= true)] public class LandLines : RDEMainForm
[Code]....
This gives me a compile time error because it claims that FORM_NAME and CASE_TYPE is not defined, even though the class has it defined inside.
How can I use the defined constants inside the class in the class attributes?
I am trying to retrieve the Attributes of a class's property specifically. So for example. Let's say I have a class called "Employee", and a custom attribute called CustomLabelAttribute with a string value. What would I need to do to retrieve the value of CustomLabelAttribute for Employee.FirstName specifically? I assume I will need to use reflection, but it's kind of new to me, and I've just recently started using it on any level.