I'm just needing a simple bit of code for vb.net that will allow me to marshal an object into a string, allowing for the saving and loading of this string so I can save my classes, needs to be simple and easy!
View 1 RepliesSave & Load all object property within a form??
I have been working on thread [URL], but it only limitation is it cannot save and load control that is child control (within groupbox, tabcontrol)..
I didn't think it fair to post a comment on Fredrik Mörk's answer in this 2 year old post, so I thought I'd just ask it as a new question instead..NB: This is not a critiscm of the answer in any way, I'm simply trying to understand this all before delving into memory management / the marshal class.
In that answer, the function GetByteArray allocates memory to each object within the given array, within a loop.Would the GetByteArray function on the aforementioned post have benefited at all from allocating memory for the total size of the provided array:
Dim arrayBufferPtr = Marshal.AllocHGlobal(Marshal.SizeOf(<arrayElement>) * <array>.Count)
I just wonder if allocating the memory, as shown in the answer, causes any kind of fragmentation? Assuming there may be fragmentation, would there be much of an impact to be concerned with? Would allocating the memory in the way I've shown force you to call IntPtr.ToInt## to obtain pointer offsets from the overall allocation pointer, and therefore force you to check the underlying architecture to ensure the correct method is used*1 or is there a better way? (ToInt32/ToInt64 depending on x86/64?)
*1 I read elsewhere that calling the wrong IntPtr.ToInt## will cause overflow exceptions. What I mean by that statement is would I use:
Dim anOffsetPtr As New IntPtr(arrayBufferPtr.ToInt## + (loopIndex * <arrayElementSize>))
I've read through a few articles on the VB.Net Marshal class and memory allocation; listed below, but if you know fo any other good articles I'm all ears![URL]..
I am looking for the windows mobile equivelent of a flow layout panel (or any other control that I can use to hold custom controls)
View 2 RepliesI'm trying to figure out how to set/change text within a cell in a DataGridView control. When I was using the MSFlexGrid, I used the TextMatrix function. How can I do a similar function in vb 2008?
View 1 RepliesI have a string which contains XML. I want to create an XMLdocument from this. I am using Load and LoadXMl methods like this:
Dim doc As XmlDocument
doc.LoadXml(applicationXml)
but they are retuning:
Object reference not set to an instance of an object.
My XML looks like this:
<gate.util.persistence.GateApplication>
<urlList class="gate.util.persistence.CollectionPersistence">
<localList>
[Code]....
I'm currently converting a Visual Basic application to Ruby because we're moving it to the web. However when converting some algorithms I've run into a problem concerning bit shifting.How I understand it, the problem lies in the size mask VB enforces on Integer types (as explained Here). Ruby, in practice, doesn't differentiate in these types.
[Code]...
Okay, so I'm using this code to save a webpage to a file:
Dim myWebClient As New System.Net.WebClient
myWebClient.DownloadFile(mainbrowser.url.tostring, _
"C:/currentpage.html")
[code].....
This is the general goal I am trying to achieve:My VB.NET program will generate some Lists that may contain booleans, integers, strings, or more lists. I want the program to output a "file" which basically contains such data. It is important that the file cannot be read by humans Okay actually, fine, human-readable data wouldn't be bad.Afterward, I want my Ruby program to take such file and read the contents. The Lists become arrays, and integers, booleans and strings are read alright with Ruby. I just want to be able to read the file, I might not need to write it using Ruby.
View 2 RepliesI would like you all to give me some links about embeding scripting languages and I would like to ask if it is possible to embed Ruby into a Vb.net application. I only know Vb.net c# and ruby and would prefer not to have to learn c/c++ (even though i probably will have to in the very far future).
View 3 RepliesI have a finished a software written in ruby on rails. It is possible to convert it to visual basic?
View 3 RepliesI'm a VB6 programmer who was forced to upgrade to Visual Studio 2005 Version 8.0.50727.42 .NET Framework Version 2.0.50727. I am trying to write a call-back which will intercept a Windows message for when our USB HID device is plugged or unplugged. We have a custom .dll which handles the majority of the HID interface. I just need to call a few API's to connect to the device. I can connect and communicate.
I am looking at USB Complete Third Edition. The code examples do not compile. I'm unsure if this is because of the .NET version 2 or the 2005 dialog of VB. I cannot resolve "StructLayout..." statements, but the program appears to be working without them. I cannot get any "Marshal." statements to compile, which is where I am finding it difficult to get around.
[Code]...
Although OnDeviceChange() is being called six times, both IF statements fail. m.msg is 0x219, which is Device Change. m.WParm is always 7, m.lParm is always 0. And, this is where I'm stuck. m.lParm should be a pointer which gets me to the device path? Don't know what 7 is.
So, maybe I'm not registered to receive the proper messages from the device (or I'm looking in the wrong place). The missing step might be to call the RegisterDeviceNotification() API. This book is telling me to use frmMy.Handle declared globally as Friend frmMy As frmUSB - that gives me a null reference runtime error, so I swapped in Me.Handle for the first parameter to RegisterDeviceNotification(). It likes that. But, then it has heartburn with the buffer pointer - not so easy to resolve in Visual Basic. The call wants a LONG. I have DevBroadcastDeviceInterfaceBuffer, which the book says to use Marshal.AllocHGlobal(Size) and Size is Marshal.Sizeof(DevBroadcastDeviceInterface). Neither Marshal statement compiles and I'm not sure if it was removed in this version of .NET? Anyone? I really don't need a dynamically allocated buffer. This is quickie VB app for a single USB device.
Can anyone tell me how far down the rabbit hole I am and what I'm missing. I can tell when something changes to some USB device. I have a handle to that device supplied to me by a custom API library - probably is the HID handle.
How can I setup to receive a message when my HID USB device is unplugged or plugged in?
How would I create a list of elements in VB.NET, save it to a .dat file, and make Ruby re-create such list (as an array) with such elements (they will be strings, booleans and integers)?
View 2 RepliesI need an array with fix String lenghts and fix rows... I do this...
Imports System.Runtime.InteropServices
Public Class Class1
Public WPFFunktion As String
[code]....
We are trying to communicate between our two applications, One is in VB.Net and the other one is in ruby. We can easily communicate between two .Net applications but how to communicate between a .Net and ruby application? [code] After creating the Memory Mapped File through the above code how can we read/write it in ruby?
View 1 Repliesread/write from VB.Net to ruby application and vice versa using Memory Mapped Files?
View 3 RepliesWhat is the most timers you have used in an application? I think the most I have ever used is 2.In another forum this question was asked. "I have a Timer ... I have a situation where I want to run the code in the Tick event ONLY ONCE not on the interval i have the timer set too."
I responded with Timer1_Tick(New Object, New System.EventArgs) Which led to this "The 'sender' object is VERY important when you have more than one Timer being handled by the Tick event procedure. This is because in a multi-timer tick event procedure, the only way your program knows which timer just fired is by querying the 'sender' object.When you use code like this you are putting nothing into the 'sender' object, so that if you were ever going to query it a 'kaboom' is going to happen.""...this 9 timer Tick event handler job done. Remember, all that is required is the correct timer name gets put into the ListBox." "The need for multi-timers to be handled by a single Tick event handler happens all the time. How would a real life programmer handle this? "Oh, to test the "kaboom" theory I wrote this and ran it overnight successfully:
[code]...
I am using a COM library in my VB.NET app that has an asynchronous execution method and signals my application via an event when it completes. The event handler is on a different thread from the calling thread. I want to invoke another execution on the main thread when I receive the completion event. If I call directly in the event handler for another execution it starts on the new thread. How do I marshal back to the main thread. This is done in a dll not in a form.
View 3 RepliesI'm trying to call the GetInterfaceInfo Windows API - it accepts a structure as one of its parameters and this structure has a member that is an array. The API populates the contents of the array when it is called and there can be any number of items in the array. How can I define such an array in my structure?
If I just use a normal .NET array like so then the program just crashes (no exception thrown)
<StructLayoutAttribute(LayoutKind.Sequential)> _
Public Structure IP_INTERFACE_INFO
Public NumAdapters As Integer
[Code]...
and this works fine, but the problem is I have to define the SizeConst attribute as you can see to something large (64 in this example) so that the API doesnt fail because the array wasnt big enough. Firstly this is a waste of memory as in most cases the number of items the API sticks in the array will be less than 10, but secondly if there was ever a case where the API wanted to put more than 64 items in then it would fail.
Using ReDim to set the length of the array at runtime seems to have no effect, and that SizeConst attribute has to be set to a constant value so there's no way I can dynamically set it.
creating a business layer in a .dll which at the moment is being used on a windows forms application. I have some objects with properties that use iNotifyPropertyChanged to update the UI which has all been working fine. My problem is tarted to explore using multiple threads and ing a cross-thread error because the properties are being changed on a different thread to the UI and iNotifyPropertyChanged is attempting to update the values (shown in labels) on the UI thread... shows the best way to solve my problem. The .dll will never know what Forms application is using it so I really dt want to hard code references into the objects. From what I gather this code allows you to register a form with the .dll and then add the invoke to OnPropertyChanged to avoid any threading issues. Is this correct?
View 5 RepliesI get an AccessViolationException using this code (attempted to access protected memory, this is often an indication that other memory is corrupt) on the line in DoWaitNotify that copies the pixel data back to the location in memory. In my experience, that usually means that the array is too large, but it all seems to check out. Does image data expire after a certain time or something?
Public Class Form1
Private Const NUM_THREADS As Integer = 3
Private Original As Bitmap
[Code]....
VS 2010 [RESOLVED] Marshal.ReadInt32 -> AccessViolationException
View 6 RepliesI tried to translate this code to vb.net using Marshal.copy but I can't get it to work
for (int y = 0; y < bitmapdata.Height; y++)
{
byte* destPixels = (byte*)bitmapdata.Scan0 + (y * bitmapdata.Stride);
[Code]...
Is there a way to load an object based on the variable's name as a string?
e.g. Dim MyObject as Object = ' Load by object name as in: "MyObject" & someVariable
Marshal attributes to be passed as an argument in this Declare statement? [code]...
View 3 RepliesDataGridView i will like for DataGridView to Save when i close my application and i will also like to Load when i open my application.
View 5 Replieshow can i save load a listbox? [code]
View 2 RepliesI wanna save and load my color selected by ColorPicker like this[code]...
View 9 RepliesI have been playing around with Visual Basic for about a week now. I created a program that I use at work basically just to organize my day.
The program consists of buttons that link to programs and spreadsheets that I use often, as well as a checklist of tasks I've completed and text boxes that I use for reminders. Other buttons affect GroupBox texts and Label texts.
What I'd like to know is how I can implement a Save and Load button? I'd the current state of the program to be saved so it can be loaded in the event that I have to shut the program down. (Check boxes checked, Text in Text boxes, Labels, etc...)
I've been looking online for HOURS and I've messed around with the SaveSettings feature... nothing seems to work.
I have a treeview control that contains an Active Directory OU structure and I want to save this to an XML file, and load it again later.
When I save an OU that has a space in the name, I get an "XMLException was unhandled" error. The description is "The ' ' character, hexadecimal value 0x20, cannot be included in a name.".[code]...