Is it possible to handle exceptions on the AppDomain.CurrentDomain.UnhandledException callback? I want to do the following:Show my own "an exception hasoccured" dialog, with a "Send Report"button After the user dismissed thebox, I want to close my app, but I donot want to Windows default crash dialog "Theapplication needs to close" box toshow up.
View 2 RepliesAn application raises the UnhandledException event when it encounters an unhandled exception.
For instance, you can use this event to ask user send you a report by email.
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I published my VB 2008 Express application and installed it on a test computer. The test computer has .NET 3.5 on it, but does not have any Visual Studio development programs on it (I think this is the best way to really test it before sending it to other users. It works fine.The application reads some data from a text file. Every few days, I need to update this text file and send it to the user. (I do not want to republish everything, and I do not want to run a web server.) I naively (??) designed things so that this would be done by attaching the new text file to an email and sending it to the user. The user would simply (?) save this attachment to the same directory as the .exe was in (the application directory). In the old days, there would have been an .exe file in some folder like c:Program FilesDavewareMyprog.exe. And my .txt file would be right beside it.In the code, I have used
System.AppDomain.CurrentDomain.BaseDirectory() & "MyDataFile.txt"
in various places where I use a Streamreader and Streamwriter to access it. But I've now sent an 'update' email with the .txt file to the test computer, and proceeded to save the attachment, and then realized I'm stuck. I can't find any directory that looks like it might be a good old application folder. In fact, there are references to my application all over the place, in very ugly looking paths.Now I think I'm in trouble as I read the MSDN on BaseDirectory, which starts out:"Gets the base directory that the assembly resolver uses to probe for assemblies".Is there any way I can do things as I designed it? I can think of some work arounds, like try to hard code some folder off c: that has nothing to do with where the .exe is etc, but putting it in the 'application folder' seems so much easier and wouldn't require knowledge of which drive the .exe ended up on etc. on the user's computer.
I have a SqlDataSource that is supplying data to my GridView. Thats all i am using on my form, thus i have NO code behind at all. But somewhere i need a TRY CATCH block just in case my connection get's lost. What code must i place where?
If i get a error i want my lblMessage Text to be "No connection".
Edit
My GridView in my Machine.aspx
<asp:GridView ID="GridView1" runat="server" AllowPaging="True" AutoGenerateColumns="False"
Height="209px" PageSize="7" Width="331px" AllowSorting="True"
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I was reading a couple of articles a while back which I think described a behaviour where you can, in a .net application (specifically VB.net), allow an exception to occur, and then handle it in some kind of application-level exception handler, as opposed to within a Try/Catch block. My google-fu is weak at the moment, so I'm not having much luck guessing what this feature is called in order to find information about it.
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I am working on a .Net Remoting project. If there is any exception in remote object, I would like to send this exception in detail to the client. I am using the following code to accomplish that-
'This is on a shared .dll
Public Interface ICreateNewMouza
[code].....
I created a custom collection class with some methods: each of these has some parameters and throws an exception if a parameter is not valid.For example, the Add and Remove methods throw an NullReferenceException if one of their parameters is null.[code]...The Replace method replaces an item in the collection with another specified object: to reach the goal, it first calls the Remove method and after the Add method. Obviously the Replace method could throw exceptions if at least one of the specified parameters is null, because Remove and Add methods could throw exceptions.Is this the right way to go? Or should I also check the parameters in the Replace method as in the following code? [code]...In fact, in this second case, each check would be executed twice: first in the Replace method and after in the Remove and Addmethods, which are called by Replace, and in other cases the checks may be rather expensive.
View 1 RepliesIs there a way I can catch and handle two different exceptions within the same exception type? For example:
Try
' My code
Catch ex As System.Net.WebException
End Try
I have 2 different exceptions that are System.Net.WebException. I want to handle them different ways. Problem is the catch block above catches them both. Is there a way I can determine if which of the two it is and handle them differently?
I have a relatively simple VB.NET app. It targets framework 2.0 from Visual Studio 2010. The app works fine most of the time, except that the users sometimes receive the
following exceptions. The error is completely random and somewhat rare. I haven't been able to trap it while in a development environment. It also doesn't appear to be
pointing at my code. My app continues to run if the users ignore the error. How would I trap and handle this error?
I wonder how to use statement handles exceptions?Do I need to wrap the using statements with a Try/Cath/Finally clause in order to be sure that the SqlConnection object is closed and disposed even if the containing code throws an exception? [code]
View 3 RepliesI'm writing a piece of code to manage the Unhandled exceptions in my VB application.
I'm using the following code
Partial Friend Class MyApplication
Private Sub MyApplication_UnhandledException(ByVal sender As Object, ByVal e As Microsoft.VisualBasic.ApplicationServices.UnhandledExceptionEventArgs) Handles
[Code]....
I've just skipped around a few inbuilt VB classes' methods which throws exception. of all that i've came across, methods may throw multiple exceptions but ALL of them are exclusive, meaning there is no way 2 exceptions will ever occur simultaneously, yea and i was trying to make my class throw 2 exceptions simultaneously, hence this question, must all exceptions be exclusive?
View 1 Repliesif you have this in your Application events: Private Sub MyApplication_UnhandledException(ByVal sender As Object, ByVal e As Microsoft.VisualBasic.ApplicationServices.UnhandledExceptionEventArgs) _ Handles Me.UnhandledException 'test to make ceratin handlers both fire Debug.WriteLine("AppEventFired") End Sub nd to test it you do this
Throw New Exception("1") shouldn't the Debug.WriteLine("AppEventFired") line execute? It isn't that I can tell and I have checked that I am running in Debug, not Release.
I created for my app unhandled exception it ask the if they want it to "phone home" and report the problem. I want to test the code, but I can't, since if I try to fire an unhandled exception when debuging, by typing Throw New Exception() at a point in the code, the debuger just stops the code there, not letting the UnhandledException code run.
View 4 Replieshave created a new AppDomain with a unique name. But i do not want to store that name during the whole application runtime.So i ask you guys if it is possible to get that created AppDomain by name back.
Sub Main()
AppDomain.CreateDomain("TestDomain")
End Sub
so How do i get the AppDomain with the name "TestDomain" back so i can unload it later without storing that AppDomain globally?
What is AppDomain.CreateDomain
View 2 RepliesI have an ApDomain that is running a Main Routine, for example:
Public Sub Main() Implements Interfaces.IScript.Main
For a as Integer=1 to 99999
[Code]...
Can you have more than one AppDomain in a process Or more than one process in a AppDomain? What about threads? I was always told there were many threads in one process and one processor has many processes. How does App Domains fit into this picture?To me, it seems like its the same concept with a different name??
View 1 Repliesthe forum,this is my first message, and I hope that my English is understandable (I'm Italian)....I've developed a WIndows Service using VB.net 2.0; this service executes a routine every 4 hours... I would like load a dll (without entry point) at run time and when the operation is terminated, I would like unload that. I think that I've to create a new AppDomain and to load my DLL into this, but I don't know the good way to do it.
View 9 RepliesFirst, I changed my ILS function to be simply: Public Overrides Function InitializeLifetimeService() As Object Return Nothing End Function
Then I included this in my Program as well as A. As Timiz0r pointed out, Form inherits MarshalByRefObject, so I didn't have to include a Inherits statement on my main class (which already inherited Form). This was the big thing, because I didn't include it originally. Next, I changed my AppDomain setup to be:
Dim _ADomain As AppDomain = AppDomain.CreateDomain(Name)
Dim item As New A
item = CType(_ADomain.CreateInstanceAndUnwrap(GetType(A).Assembly.FullName, GetType(A).FullName), A)
With these changes I can now use separate instances of the DLL COM object as desired.
Original Question I am writing an application that creates a list of objects, each referring to a DLL, and each object placed in its own AppDomain to keep the instances of the DLL from interfering with each other. Taken another way:Program maintains a List(Of A)A is created as an instance of AppDomain using CreateInstanceAndUnwrap Each A refers to mirror.dll, which is including in the application's references
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I keep getting a "System.Runtime.Serialization.SerializationException" in my application while loading a not-defined assembly (AKA: Plug-in loading.)Even if I turn Serialization on for that plug-in, then it will fail once again. I've been looking around and couldn't find a good tutorial about it..
So all together: How to load an assembly using AppDomain?
I have done a lot of research on the memory leaks present in the WebBrowser control, and the following thread (http:url]...) told me that the only real way to reclaim the memory eaten up by WebBrowser is to load the control in a separate appdomain.I went ahead and did this, but when I unload the AppDomain that the WebbBrowser is created in (using AppDomain.Unload()), the memory is still not freed. I am looking at the Private Bytes of the process in Task Manager (which is accurate and what I'm interested in) to confirm this. The memory usage stays at 50MB+ instead of its default 5MB.Here is my code:
Form1.vb
Imports System.Reflection
Public Class Form1
Private ad_WBInst As AppDomain[code].....
I'm kinda new here, and I didn't know what forum to put this in, so I just put it here. I wanted to load an assembly to an Application Domain, use it, then unload it when I'm done with it. The assembly uses too much memory. The problem is: After I unloaded the assembly, the memory used is not getting freed. I was watching the performance all the time. The available memory increases only after I close the whole application. And that assembly is the only thing that uses a lot of memory in my application. Here's the code I used to load and unload the assembly: How can I free up the memory without closing my application. The memory was suppose to get freed up by simply unloading the assembly that uses it much.
View 2 RepliesI have an Addin for MS Excel which needs a singleton to share data amongst modules.Depending on the version of Excel (2003, 2007, 2010), and how Excel was started, it calls my addin from different, unpredictable AppDomains, which prevents the classic singleton approach.Creating a custom AppDomainManager won't work because Excel has already created the AppDomains before the addin is called.
Linking to mscoree to enumerate domains breaks the addin registration process (and I really don't want that anyway); there doesn't seem to be any other way of enumerating, so that isn't an option either.The only solution that I've found is to use remoting. Here's my test rig:
Imports System.Runtime.Remoting
Imports System.Runtime.Remoting.Channels
' Remeber to add reference to System.Runtime.Remoting DLL[code].....
Once everything is running, access to the singleton takes ~100µS, which is perfect. I can live with the ~400mS the first time each AppDomain is initialised. The problem is at startup, where the remoting invocation takes ~2.5 seconds.
I need to get the information of all the appdomain created in given process?
View 4 RepliesI have a service application that randomly stops without any errors in my log or in the event application log. I believe that there could be an unhandled exception somewhere in the code so I set up the AppDomain.Unhandled event to catch any exceptions. While trying to induce unhandled exceptions I have found that this event is not always fired. I added the following code to my service's Shared Sub Main method (but I orginally had it in the OnStart method and was seeing mostly the same thing)
Dim currentDomain as AppDomain = AppDomain.CurrentDomain
Add Handler currentDomain.UnhandledException, Address of MyHandler
I have created an application domain, using which i am executing an .exe file.So the command window does open which has the title as file name. I want to hide the command window.
Dim newAppDomain As AppDomain = AppDomain.CreateDomain("", AppDomain.CurrentDomain.Evidence, AppDomain.CurrentDomain.SetupInformation)
newAppDomain.ExecuteAssembly(IO.Path.Combine(Offic eAddInConfig.Instance.BinPath & "Core", "file1.exe"))
Here a command prompt will be opened which need to hide.
how to create a stable plugin architecture. Stable because I plan on opening up plugin creation to the public but I dont want a sloppy coded plugin to take down my whole application.
So I thought of using an AppDomain per plugin and I did a little seaching. But it seems that even using a temp AppDomain to load plugins and then unloading it once all assemblies have been inspected raises complexity allot and I was planing on using an AppDomain per plugin.
I feel the gained stability (if there is any at all) may be raising the complexity so much the app will never be done..
Is there another way to both create a stable application and at the same time making it extensible?
I cases where the host calls a defined function via say IPluginInterface I guess I can pack a whole lot of try catch blocks around that call but what if a plugin insisted of a timed routine that would run continously without being invoked from the host other that a starting call to StartPluginService or something like that?
If I include a plugin like that in the default AppDomain and it blows up I sure will blow my own foot off right?
I'm in the process of trying to create a new appdomain to load plugin dll's, then unload the new appdomain so I can update the plugin dll's without having to exit the main application. There are many, many examples out there and it looks like it should be fairly straightforward, however I'm having a problem where the main application is loading the plugin dll's along with the new appdomain. Of course this is a problem because I cannot overwrite the plugin dll's if they live in the main appdomain. Based on the examples I've seen the code below should only load the plugin dll into the new appdomain, however for some reason it also loads into the main appdomain.
Dim oDomain As AppDomain = Nothing
Dim oSetup As New System.AppDomainSetup()
With oSetup
[code]....
The IDPAPlugin interface is in a seperate project that both the plugin dll and the main application reference.
Is it possible to read the GUID from the Assembly without actually loading it in the current App Domain.
Normally Assembly.Load loads the DLL into the app domain. I just want to read the value. The description of the GUID is
'The following GUID is for the ID of the typelib
' if this project is exposed to COM
<Assembly: Guid("DEDDE61CD-928E-4ACD-8C25-3B8577284819")>
The main thing is I don't want to lock the file so that there are no errors 'Another process is accessing the file' error.