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Marshal gethrforexception vb net

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The docs for Marshal. GetHRForException say something that worries me http: Allowing an exception to propagate outside the method produces incorrect behavior. In fact, the common language runtime fails to pass an exception to a COM client calling such a method through a v-table. Since I have removed all the PreserveSig attributes from all my interface methods and have moved to a completely exception-based approach for my library, this would be bad. In my COM objects, I use "throw" all the time for sending back errors to the caller both managed and unmanaged and I have not yet seen a problem. I throw a COMException, and the HRESULT ends up in the caller's hr. What's more, the unmanaged client can retrieve the IErrorInfo interface to receive the text I throw along with the error code. Are these old docs that haven't been updated to reflect current behavior Maybe I'm misunderstanding what it is trying to tell me Or is there some horrible gotcha waiting to bite me in the, umm, marshal. Is it possible your information is out of date here I've tried to see the terrible consequences you are describing, and it just ain't happening. Code Snippet void main void. Code Snippet public void DeleteInputStream int dwStreamID. Didn't see anything else that would apply. In fact, here's the contents of the "command line" window: Just your basic compile options. I am running on Vista, but it doesn't seem net that should matter. Sorry, should have added what framework version I am using. The command line I use to register my COM object is:. Ok, I was worried. I had pulled out hundreds of lines of "if SUCCEEDED" code and deleted PreserveSig from hundreds of methods. Having to put that all back was Doc question about Marshal. GetHRForException Common Language Runtime. Most of the DB tables use the autonum feature to automatically assign a unique id to records. Is it possible with the above objects Or is there an easier approach Thanks for any help! Common Language Runtime Doc question about Marshal. NET Development 2 Comment a Gethrforexception using code In my C code I add, update and delete Net in a XmlDoc. I think once I do that and reload the doc I know I loss or there is no way to read back that Node right Thank you - Ashok Net NET Development 3 RecordsAffected and Trigger Hi, I have a update trigger for my table which will SELECT some reocrds and do update to other tables. NET RecordAffected property to check for of rows updated. I found that, RecordAffected value returned is not corrected cause by the SELECT statement in my trigger. Any way to prevent it Thank you Tag: NET Development 4 Web Service call seems to block other calls to same service The same behavior can happen with a console client as well. NET Development 5 NetworkAvailabilityChanged not firing I have an occasionally connected app which dials the modem via RasApi. It seems that I cannot count on the NetworkAvailabilityChanged event when the net of a RAS connection is changed from outside the Network Connections control panel. For example, right-clicking on the connection in the taskbar notification area usually does not fire the event. Dialing the connection via RasApi seems to only fire the event the first time per session disconnect and dial again: I can reproduce this on XP home and pro. Is this a bug in. I have been trying to figure marshal out without any success, and msdn says that these functions are built in, but does the. Here is an example below: Add "A", "Justin" ; HTable. Add "B", "Robert" ; HTable. Add "C", "Scott" ; HTable. The key value of 'A' already exists, which I know and I want it to perform the collision resolution. Is there a step that I am missing here Is the collision resoluiton process the same for a Hashtable as well as a Dictionary Please help because I am truly confused on what to do without building in my own functions to fix this error. NET Development 7 Problem in implementing IEditableObject for doing n-level Undo?? I have implemented IEditableObject interface in my custom object base. I was trying to do undo functinality by filling a Dictonary object in BeginEdit and reversing gethrforexception when CancelEdit. I know it's diificult to explain. Can I get any attribute or method by which I can stop the object to again reinitialized ASCII or ANSI System. It works fine if i use Unicode System. Unicode encoding, but i do would like my file to be in ANSI format rather than in Unicode format. Default encoding Any help on this is would be greatly appreciated. NET Development 9 import certificate into internet explorer IE keystore hi how can i import certificate into internet explorer IE keystore thanks Tag: NET Development 10 How to validate an XML file Your example uses WriteXml to write an XML instance document and reads that document back in. With that test you will not get validation errors as the XML written conforms to the schema associated with the data set. As for other XML documents, I have already pointed out that validation with schemas is namespace specific, I am sure you will get validation errors if you feed an XML document to ReadXml that has the proper namespace but not the proper elements e. On the other hand, as already pointed out, if you feed an XML instance document that does not have elements in the target namespace net the schema, then the validation will only emit warnings that no schema for the elements has been found. NET Development 11 Deleting Data from a Database Multiple Tables Hi All, I was wondering if someone could help with a deleting from a database. I have followed on of the Walkthroughs "Saving Data to a Database Multiple Tables UpdateMultipleTablesWalkthrough " http: EndEdit Dim deletedOrders As NorthwindDataSet. OrdersDataTable Dim newOrders As NorthwindDataSet. OrdersDataTable Dim modifiedOrders As NorthwindDataSet. OrdersDataTable Try ' Remove all deleted orders from the Orders table. If Not deletedOrders Is Nothing Then OrdersTableAdapter. Update deletedOrders End If ' Update the Customers table. Customers ' Add new orders to the Orders table. If Not newOrders Is Nothing Then OrdersTableAdapter. Update newOrders End If ' Update all modified Orders. If Not modifiedOrders Is Nothing Then OrdersTableAdapter. Update modifiedOrders End If NorthwindDataSet. AcceptChanges Catch ex As Exception MsgBox "Update failed" Finally If Not deletedOrders Is Nothing Then deletedOrders. Dispose End If If Not newOrders Is Nothing Then newOrders. Dispose End If If Not modifiedOrders Is Nothing Then modifiedOrders. Marshal End If End Try At first the walkthrough would not save to the gethrforexception when new records were created or edit. As the code stood it only updated the database in memory. I found if I made the following change: Any Idea's how I would get this to delete Thank you for your help in advance! NET Development 12 datatable. NET Development 13 Retrive IIS Information from Remote Server and Display Data using ASP. NET or Desktop Application in Dotnet OR If any one have a code to retrieve the iis information from the remote server by connecting it with user id and password and display the details using ASP. Net or Desktop application using Visual Studio 1. Imports System Imports System. Data Private Function getPropertyStruct As DataTable Dim dt As New DataTable dt. Add New DataColumn "Name" dt. Object, ByVal e As System. Add dr Next Me. DataBind ' Catch err As ManagementException ' Response. Message ' End Try End Sub End Class Thanks in Advance Jay Tag: NET Development 14 Check if sql server is online NET Development 15 Creating A Helper Thread The latest mdbg sample http: However, I'm not sure this is what you want since you commented you would not like to build the native debugging functionality from scratch. This is essentially what you'd need to do, although you could do it at least parts of it in managed code. You'd be required to stitch the managed and native debugging architectures together. As for private interfaces, I don't believe VS uses any. The functionality they expose is via Win32 debugging APIs and ICorDebug. Needless to say, a tremendous amount of work has gone in to the interop support VS provides. Now i am using this assembly Add reference in some other assemblies Assb1 and Assb2. In Assb1 i do not want Cls2 to be visible, but Cls1 should gethrforexception visible. Here i should be able to get the property values, setting property values should not be allowed. NET Development Next 1 ZIP File Creation Using C and Shell I would like to use the zip file as a container without compressing the files. Have you noticed how to specify the compression method Tag: NET Development 2 Remoting Hi, I am using Remoting concepts in my project. But i am not sure whether i am heading in the right direction. NET Development 3 Microsoft. What gives I tried to uninstall 1. Is it telling me that it's going to uninstall 2. NET Development 4 Task Scheduler doesn't show. I am using the click once deployment. Normally I just run this program on a server and it runs continously, doing the backup at the time selected in the program. I have a customer that wants to run the program on here XP machine. She sometimes forgets to start the program, she doesn't get the backup. I wanted to set up a task in scheduler to run this program at a time prior to when the backup is schedule in my backup program. The backup program, nor any other. I realize that the program is stored deep in the documents and settings folder. I thought maybe I could just browse to the icon that starts the program and start it that way in scheduler. That doesn't seem to work either. Any ideas Thanks, Douglas Tag: NET Development 5 WebServices How can I host my WebServices Tag: NET Development 6 xmlns: The CollectionViewSource WPF sample code found at http: Error 1 Type 'SortDescription' is not usable as an object element because it is not public or does not define a public parameterless marshal or a type converter. Control adds a Text "Label" control in the parent control's collection when the control handle is created. Position and size of the control is evaluated on runtime and positioned properly in the parent control. The problem is, when i drop this control from designer on a TabelLayoutPanel, the label never gets the proper cell on which it is dropped. TableLayoutPanel only allows a single control in a cell. Is their any solution for this problem I have tried to make a container control and adding the two controls into that container, but that way i have to write all the functionalities of combo box on the container the problem appear to be solved but now i get more coding and i am getting into more problems as this is a databound control. Also i need to have the base to be ComboBox only. Thanx, Shariq Muhammad Application Development Tyler Works, Incode Division Tag: NET Development 8 Vista framework version incompatible with XP version PhilipRieck wrote: Peter, This is not just academic, actually. I had an application "in the wild" FAIL on vista marshal of the difference in versions. And there is no way to determine the version short of file property sniffing on some of the actual DLLS you can't use requiredruntime or anything similar. NET Development 10 Timeout expired. The timeout period elapsed prior to completion I am calling 4 functions to access data while loading UI Form. Interesting thing is that it occurs occasionally once in more the calls, my ideanot every time. NET Development 11 Invalid name character hexadecimal value 0x20 Hi, I am retrieving a string from the app config and splitting it. The split strings are then stored in an object and later written to a Xml file using XmlTextWriter. Invalid name character in 'Item 1'. The ' ' character, hexadecimal value 0x20, cannot be included in a name. I have tried converting it using different methods, but have so far been unsucessful. Can anyone tell me how to overcome this problem. NET Development 12 Unable to serialize nested objects from a webmethod I am return an object from a webmethod which has an array of nested objects. The problem is that the base objec gets serialized but the array of nested objects doesn't serialize. I have used XMLInclude and XMLArrayItem attributes. My class layout is like this. Class A has a nested public property which retuns an array of class b ie. User stores a bunch of fragments of formatted text in SQL DB via, say, a RichTextBox on a windows form. They later get to use via an interface some or all of those fragments of text to automatically build a complete Word document. It's the finer points of that data storage and retrieval I'm having headaches over. I've managed to get perfectly formatted text in and out of a varbinary field using FileStreams, so I know in principle it works. Thing is I'd rather not have to use temporary files to move the data around - seems likely to be pretty clunky and slow to me, particularly as I'm not storing entire documents in the DB, just smallish paragraphs of text. Any idea on alternative options I'm new to this area so I'm assuming there must be lots of cool techniques I have no idea about. NET Development 14 Loading Assembly into new domain Does the error still occur when you don't set the appdomain's policy Also what does the Fusion log look like From the exception it appears that you're calling AppDomain. Load "Testing3" ; are you doing this or are you using the full name Tag: NET Development 15 real-time file update Under public Form1 and under InitializeComponentplace CheckForIllegalCrossThreadCalls to FALSE. This allows for more than one access attempt to a control. NET Development 16 how to zip an entire folder by using c? GetHRForException nobugz Yes, you are committing a major sin. You are expecting the COM client to catch the managed exception. That's going to fail miserably when the client isn't a managed app and will terminate the client. COMException is only for use by the run-time. You must return failures through the HRESULT return value. They then in turn typically generate exceptions in the client such as COMException in a managed app. I'm surprised your approach works at all. Some COM clients install an SEH exception handler to trap asynchronous exceptions Division by zero, Stack overflow, Invalid memory access, stuff like that. Perhaps it works because that handler traps the COMException. But that is an implementation detail of the client. GetHRForException LGS Is it possible gethrforexception information is out of date here I've tried to see the terrible consequences you are describing, and it just ain't happening. GetHRForException LGS Sorry, should have added what framework version I am using. The command line I use to register my COM object is: GetHRForException nobugz Okay, I might have overdone the "sin" bit here. Which indeed was a sin in the unmanaged days, long ago for me. The fact that it works is quite compelling evidence that the CCW wrapper is catching COMException and generating the HRESULT return value from that. It is probably bigger than that, I'd imagine it catches Exception and calls Marshal. It would have to, there's no way that a COM client could catch a managed exception. I'd say you're good to go, sorry for the confusion. The documentation could be a bit tighter here. Thanks for letting me run this past you.

Visual Basic - Error Handling with the "Try Catch" block

Visual Basic - Error Handling with the "Try Catch" block

2 thoughts on “Marshal gethrforexception vb net”

  1. AngeLa129 says:

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  2. AFoST says:

    It was soon time for them to take a break and as they walked away, they referred to my DD as their great stepper.

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