What is the best way to get a structure from memory, I know the format:
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The structure is 53 bytes until the chat text, the message length is determined by one of the structure variables LineLength, so what is the best way to get that and put into into a structure?
How can I copy from a structure to the memory referenced to by a pointer back and forth?I need to do it with an offset.
Dim g_memoryPointer As IntPtr
Dim teArgs(10) as ArgumentStructure 'a structure defined somewhere outside my prog
Dim ix as Long, offset as Long
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I was wondering if there was a way to find out how much memory a data structure too up. So say I declared a list of strings.
Dim theRN As New Dictionary(Of String, Integer)
Say it had 25 elements in it. How to find out how much memory those 25 elements are costing me?
Module Module1
Public Structure structure1
Public TRANS() As structure2
End Structure
Public Structure structure2
Public X() As Integer
End Structure
End Module
I'm new to VB 2008 after having spent a long time with VB6, so I apologize if this is a stupid question. But I'd really like to have this straightened out.
Let's say I have a pretty large structure that has lots of properties.
Code:
Now say that I want an internal database with about 10 instances of this structure total, describing, say, 10 different products that a store sells. When these values are loaded from a database, they remain totally static. (However, they can be different each time a program loads)
Now say that I have a class. Each instance of this class is a type of that BaseProduct structure. Meaning, each instance of the class pertains to one of the 10 types of products that the store sells. However, this class has additional properties that pertain specifically to each instance, which are not static.
Code:
Now, the problem here is... If I have 200 different transactions, each one contains an instance of BaseProduct. BaseProduct is HUGE, and is largely redundant (only 10 types possible), so I think it's a little silly to include a whole copy of it with EVERY transaction. However, the Transaction class really needs information regarding the base product it pertains to. Is there a way to, instead of declaring a New BaseProduct in the Transaction class, to simply make one of the properties of the Transaction class a pointer to a BaseProduct variable?
In VB6, I would accomplish this by making a BaseProduct(10) array, and then giving each Transaction an ID number referring to an entry in that array. But in VB 2008, using class structure, this is impossible. I can't define the BaseProduct(10) array outside of a class in a namespace, and if I define it in the actual application's form, then the class loses modularity since it relies on the application that's using it.
I am trying to communicate with an external device and i am trying to send a byte array to the external device via sockets but i am always getting a response the message size is too small so i am not sure what i have done wrong. Between the data type there should be no alignment present and all numbers are represented in little endian format. The char array is not null terminated as mentioned in the protocol specifications.
I have to send data based on a struct that embeds 2 other struct. So here's my vb.net code for the struct used to convert to byte array and the sending part.
Public Structure MESSAGETYPE_OIP_Login
Dim Header() As COMMANDHEADER
Dim UserName() As PSTRING
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I'm experiencing a problem with the following c-structure:
typedef struct tagTEXTUREPROP
{
DWORD dwSize;
[Code].....
The Marshal.SizeOf obviously calculates a size of 76 and it works with the DLL function, but it leaves me with some bad feelings.
I'm having a problem that's driving me crazy; I can't understand how to convert the XML structure into a class structure (that I want to use to hydrate a XML document).
The XML document looks like this:
xml
<?xml version="1.0" encoding="utf-8"?>
<artists xmlns:opensearch="http://a9.com/-/spec/opensearch/1.1/" xmlns="http://www.spotify.com/ns/music/1">
[code]....
In VB 2005, I am calling a C++ DLL function that returns the address in memory and size in bytes of a jpeg image. How can I load that jpeg image directly from memory into a picture box in my VB form? I cannot afford to save it to disk first.
View 10 RepliesIm getting a problem with one of my programs I have made in visual basic.NET where it gives me a memory error when i debug the program in the IDE. the exact error is this: "Attempted to read or write protected memory. This is often an indication that other memory is corrupt". My program basically has a few forms with text fields on that get their text values from an access database on the same hard drive. Im wondering if im doing something wrong because my program just seems to eat up memory whenever it does anything. For example I have one form that has a combobox on it and when you change the drop down list selection it retreives a few strings from the database and puts them into the relevant text boxes, if you keep changing the selection then the memory usage (in task manager) just keeps going up and up. occasionally I get the error mentioned above when debugging but in my built version of the program it throws an exception everytime the memory usage gets past 49K.
Also I noticed when debugging in the "immediate window" frame I get the following message often:A first chance exception of type 'System. Invalid OperationException' occurred in System.Data.dll...Do I need to somehow be "releasing" the memory that is used to gather data once it becomes redundant?
I am using the following code
This error occurs :
Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
Public Class FormRegEnumValue
[CODE]......................
QuoteSystem.AccessViolationException was unhandled Message="Attempted to read or write protected memory. This is often an indication that other memory is corrupt." Source="System.Windows.Forms"
Im designing a web browser and i continue to receive this error after going to about 3 websites it crashes with that error.
I have a BackgroundWorker object that I instantiated to perform a DB process on a background thread ansynchronously. I have event handlers for DoWork and RunWorkerCompleted. I can tell that the BackgroundWorker is disposing of itself because I added a message box into the Disposed event handler.Is it necessary to detach the event handlers to ensure that the memory is cleaned up and that there are not memory leaks?
View 1 RepliesI've noticed that every time I start a new thread in my program, the memory usage jumps about 1000k and it never goes back down. I have ensured that the thread is no longer running, and only one instance of my worker thread is ever running at a time. I am using ThreadPool.QueueUserWorkItem and ASyncOperation to get stuff done. The program starts using a Sub Main in a module that uses STAThread; I read that using STAThread instead of MTAThread makes it impossible for the Garbage Collector to get in and consider objects for garbage collection. However, when I change the STAThread to an MTAThread, the WebBrowser control in my frmMain cannot be instantiated.
I get this exception:
Code: An unhandled exception of type 'System.Threading.ThreadStateException' occurred in System.Windows.Forms.dll
Additional information: ActiveX control '8856f961-340a-11d0-a96b-00c04fd705a2' cannot be instantiated because the current thread is not in a single-threaded apartment. I do threading with the WebBrowser control, so will using MTAThread fix my problem? If so, how should I partition my code so that the WebBrowser control won't be affected by the above exception? I call the thread repeatedly with a timer (although only one instance ever runs at a time), and my program's memory usage starts at about 5000k and can jump to 300,000k+ depending on many times the thread needs to be called.
I cannot use Visual Basic 2008 at all. When I go to "new project" and choose "Windows Form Application" I get this error.I have tried multiple uninstall/reinstall with no result.A microsoft reply to this suggested that I needed: " .NET Framework 2.0 Service Pack 1 " I checked, and I did not have the .netframework 2.0 service Pack 1.
When I tried to download and install the above from Microsoft.com, the istaller said that "it was not allowsed" and I was not able to install the service pack 1.
I tried Uninstalling net framework 3.5, 3.0, 2.0 and then reinstalling .netframework 2.0 sevice pack 1; then reinstalling Visual basic 2008 express edition. At the reinstall of Visual basic 2008, .netframework 2.0 sevice pack 1 is unistalled by .net framework service pack 2.When I check the foruims for simiar problems, the formus are mostly for Visual basic 5.0, or other programs that I do not have.
Here is the programs I have installed:
Operating system: Windows XP
Microsoft .net framework 1.1
Microsoft .NET framwork 1.1 Hotfix(KB928366)
Microsoft .Net Framework 2.0 Service Pack 2
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All the security updates and hotfixes for Widows XP.
The follow code can be called about 6K times on the server it is run on then gets a out of memory error in the last catch statement. I don't see what is wrong with the code, it works well up until the out of memory..
Public Function AddUserToGroup(ByVal sSamAccountName As String, ByVal sGroupName As String) As Boolean
Try
Dim returnStatus As Boolean = True[code]......
I have two forms, Form1 and Form2. Form2 has a button to show OpenFileDialog. I call Form2 from Form1 by a button. My startUp Form is Form1. When i start debugging, i press my Form1's button to show my Form2, it shows, but when i click On Form2's Button to show OpenFileDialog it is giving me exception that
"Attempted to read or write protected memory. This is often an indication that other memory is corrupt."
When i set my startup Form to Form2 and click Form2's Button to show OpenFileDialog then it shows!
I want to make a structure within a structure. Basically it will appear like this:
Structure ID
dim CardType as string
im CardCode as string
[code]......
In Vb.net I am trying to assign an array of structure to another array of same structure[code]...
View 2 RepliesI have a new problem with this same Form Printing project and I get exactly the same exception but from the different point of code:
line 538: d.PrintFunction(c, typePrint, mp, x, y, extendedHeight, ScanForChildControls)
The exception type is System.AccessViolationException and it says (after I translate it from my own language in which the message is given in my pc, into English):"Protected memory was tried to be read or written. This often indicates that the other memory is damaged"
I am getting the following error: "Attempted to read or write protected memory. This is often an indication that other memory is corrupt". i am using interop service.
View 2 RepliesThis code was put together for a one time run. It's purpose is to count all the pages in a group of images. After about 6000 of 1,250,000 images in ##X it throws an "out of memory" error. Besides it being thrown together for a one time run does anybody see anything obvious that could be causing the error?
CODE:
I have two structrures
Public Structure PhoneScheduleEntries
Dim Count As UInteger
Dim PhoneSchedule() As PhoneScheduleEntry
End Structure
I am using VB.NET 2010 and accessing a DLL that was created in VB6.I added the DLL in the References, and in the program I do the following:
Dim
RTF As
myDLL.clsRTF
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I have created a public structure:
Public Structure LogicalEdge
Dim sTypeEdge As String
Dim dTotalLengthOfLines As Double
Dim lstLinesInEdge As List(Of Line)
End Structure
In my code, I create a new list of this LogicalEdge:
Dim myListOfEdges As List(Of LogicalEdge) = New List(Of LogicalEdge)
After, I create a new LogicalEdgecontainer:
LogicalEdge = New LogicalEdge
I set one of it's properties:
LogicalEdge.sTypeEdge = "endcap"
Now, I add it to the list
myListOfEdges.Add(LogicalEdge)
After looping a few times, i want to set one of the other propterties for the same item in my LogicalEdge, but when i do this:
LogicalEdge.dTotalLengthOfLines = 80.77
To look at the values in the collection, I loop through myListOfEdges collection; and I see that dTotalLengthOfLines doesn't pick up the value i have assigned to it. i thought I might need to identify which item in myListOfEdges to add it to... so i tried this:
LogicalEdge = myListOfEdges.Item(i)
LogicalEdge.dTotalLengthOfLines = 80.77
But that didn't work either.
I'm sure there is an answer to this somewhere but I'm clearly using the wrong terminology in my searches, so I apologise in advance for this inevitably being a duplicate.Take the function CType. Clearly I can cast (or at least try) a given object to a given reference type. The function will not work if trying to cast to a structure, i.e.CType(myObject, Integer)
will generate a compiler error. This I'm sure most often crops up when working with generics:
[Code]...
What is the opposite? I want only reference types so that CType doesn't fail. I can't overload the T As Structure with a plain T because it considers them identical signatures, so surely there's a keyword I'm missing somewhere?
Recently I found that I'm not able to instantiate a structure for an array:
Dim mObjectLists() As New objectLayout
Ok, fair but It's an easy way to store a bunch of data in an array instead define a class. And after that I tried to define this:
Dim mObjectLists() As Collection
And add structures to the collection. But it says you should instantiate the reference object first. I searched about creating own Collection based on the base collection class but I think It's wasting time to write a code with class inheritance instead the first sample.
add a structure to a list
View 2 RepliesIn a recent project I was working I created a structure in my class to solve a problem I was having, as a colleague was looking over my shoulder he looked derisively at the structure and said "move it into a class". I didn't have any argument for not moving it into a class other than I only need it in this class but this kind of falls down because couldn't I make it a nested class?
View 5 RepliesI need to convert structure from VB6 to VB.Net. This struct is used to pass to a c++ dll. The problem is that the following struct size in VB is 113, but for some reason in VB.Net is 116.
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