If i use a stream to modify few bytes in a file without changing the total number of bytes
does the stream rewrite all the file even if just few bytes have been replaced?
i am working on an application called logonscreenchangerxp i made my program and when i run it on xp virtualmachine i get errors the program is made using vb 2008 and using .net framework 2.0 i am not able to get full permissions to modify boot.ini file and a regisrty value and to delete a file
View 5 RepliesHow to convert memorystream byte array to csv file. I have GetExport method that converts rpt file to excelformatted memorystream and then returns that as a byte array. Is there a way to convert this byte array to a csv file? Due to some reasons I can only pass this byte array back to calling function.
Public Function GetExport(ByVal reportID As ReportID) As Byte()
Dim byteArray As Byte() = Nothing
Using expRptDoc As ReportDocument = New ReportDocument()
Dim rptFileName As String = Server.MapPath(ReportCommand.GetXMLReportPath(reportID))
expRptDoc.Load(rptFileName)
[Code] .....
I just converted the following code from c# to vb.net. It is functional and works correctly with my company's firmware/devices. My next challenge. Previous serialport code used much more readable structs which where then converted (after building a packet) into byte() automatically as part of the serialport encoding. (this is my understanding)How could I
1. morph byte arrays 'ToSocket' and 'ToMTP' below into structs and
2. convert into byte array for Socket.BeginSend(byte(),.....) to stream out to remote devices?
Imports System.ComponentModel
Imports System.Text
Imports System.Net.Sockets
[Code]....
How do I read a raw byte array from any file, and write that byte array back into a new file?
View 3 RepliesI am developing an application that Monitors a specific folder for file changes such as modify deletion, update, etc. The only problem I have is , the application doesn't fire up File events.
Here is the code:
Imports System.IO
Imports System.Diagnostics
Public Class Form1
[CODE].............................
I don't know whether it is simple or not because i am new to programming. my requirement is : In my vb.net winform application, the filenames of the files present in "D:Project" willbe displayed in DataGridView1 control. Now I want to load these files one after another into memory stream buffer and add the headers("ID","Name","Class") to the content in the file. Then I want to save these files in "C:" with "_de" as suufix to the filename i.e.,sample_de.csv.
View 1 RepliesI am writing a backup program that zips files. Using some sample code I have the following that creates a zip file. Problem is it does not get any subdirectories or files. Where am i going wrong?
Dim azFileNames() As String = Directory.GetFiles(SourceFolder)
Dim objCrc32 As New Crc32()
Dim zipStream As ZipOutputStream
[CODE]...
Alternativley, there is another component to the zipping dll that I could probably bypass the above altogether. It is: FZ.CreateZip(DestFile, SourceFolder, True, "", "") Where DestFile is (Output stream as system.io.stream). I'm trying to read all the files, directories, sub dir and files, etc from a specific location, let's say 'My Documents' into Destfile in which the FZ.CreateZip zips the file. FZ is FastZip which is from icsharpcode.net. They have c# examples, but that's greek to me. I'm trying to just learn VB!
Is there anyway to take a static stream reader, and switch it to another text file based on the user changing the file?
View 1 Repliesi would like to ask is there anyway to read a txt file with UTF-8 encoding using streamreader or filestream. the txt file is contain some extended ASCII that makes me cannot read the characters properly. I hav tried Encoding.ASCII.GetString(Encoding.UTF8.GetBytes()) but still it return wrong character when it's reading extended ASCII code.
View 2 Repliesi am making a game in which the file stream gets a certain file(lets say a.txt) and it reads it, if it has certain values stored in the file it returns boolean(this is a function), then a sub procedure writes to the file using a streamwriter and a filestream using the same file. I am having problems, sometimes visual basic says that another process is using the file, this is before i closed the filestreams and the streamwriter or streamreader, then it gives me errors when i close the files, it tells me that it can't access a file that is already closed, i thought the filestream gets the file and lets the streamreader or streamwriter read or write to the filefound out the problem?
View 2 Repliesis it possible to report the percentage of file written by a file stream wile it is writing a large file?I am using a code like this one to write a large file
Using Fs As System.IO.FileStream = System.IO.File.Create(FolderPath)
Dim bf As New BinaryFormatter()
bf.Serialize(Fs, data)
End Using
I'm writing some text to a memory stream and need to modify it once in the memory stream The reason I can't modify prior to adding to the memory stream is that it is from some 3rd party component. Here is an example:ms = New MemoryStreamdoc.Save(ms, SaveFormat.Html)I need to do some modification to the resulting text that ends up in ms. Is there a way to convert the contents of ms into a string, and then back into a memory stream once modified?
View 13 Repliestrying to find a decent answer for my question; I do have a utf8 file which I (down)load, manipulate and wanting to save back again.The result always is that the file I produce is not in utf8 format;
Dim fs2 As New FileStream("c: est.dat", FileMode.Create, FileAccess.Write, FileShare.None)
Dim w As New BinaryWriter(fs2, Encoding.UTF8)
[code].....
When I look at a file on my hard disk, e.g. test.csv, when I look at the Properties of the file, it is officially known as, "Microsoft Office Excel Comma Separated Values File", and file types of .pdf are listed as "Adobe Acrobat Document", etc. etc. All of this information can be seen in Windows Explorer too when my folders are displayed by Details. How do you get at this "type of file" information with .NET?
View 2 RepliesI have a folder call "Client Info"
I want to searh a file inside this folder
sample file name inside the "Client Info" folder
1. ST1_127u132979jjvdj.doc
2.SB3_JKFH823NK9DS0-2.doc
3.SU2_kjwkrjhiwerwkrndd.doc
I only know "ST1", "SB3","SU2"...
this few, and then need to use this few to find the file and get the full file name IN vb code
I have an .net application with 2 processes, communicating using a network stream.The protocol consists of a set of commands, some with parameters, which are sent through the stream to the server. The server processes the command, and sends a response.
The protocol for one of the commands looks like this:
[code]...
Usually, this works fine. Very rarely (probably once every few millions of calls), The reading side gets the wrong values. I added code to trace the values sent and received. This shows that occasionally, the reading side gets two extra bytes, with the value 0, which was not sent by the writing side. These extra bytes appear in different places, e.g. in one case they were between i1 and i2; in another they were between the first and second byte of s2. Does anyone have any idea where these 2 bytes could come from? I checked my code, and every place that writes to the stream is traced, so it doesn't look like they are actually written to the stream. It might be worth noting that s1 is always 0, in the current implementation.
how to convert byte array to memory stream in vb.net.
View 1 RepliesI'm working on a licensing system for my application. I'd like to put all licensing information (licensee name, expiration date, and enabled features) into an object, encrypt that object with a private key, then represent the encrypted data as a single text string which I can send via email to my customers.
I've managed to get the encrypted data into a byte stream, but I don't know how to convert that byte stream into a text value -- something that contains no control characters or whitespace. Can anyone offer advice on how to do that? I've been researching the Encoding class, but I can't find a text-only encoding.
I try to read a stream and save it as byte array to add it later to zip file.this is the code that I use
Dim totalbytes As Byte() = Nothing
Dim iBytesRead As Integer
Dim sChunks As FileStream = File.OpenRead("c:myfile.wav")
Dim Totalread As Int64 = 0
[code]....
but there is something is not correct,
I am trying to play video files (atleast wmv, avi) from a byte stream in vb.net.Is it possible to direct this data at a wmp control?I have done this successfully with images & picture boxes, just need help with the video.
View 1 RepliesI have (with help from you) got 'full' control of Canon image capture and processing with feature recognition, and USB cam capture including frame modification on the fly. I now want to read an avi file and modify it on the run. I have found several C# and C++ routines as a good basis, (Especially the steganography example) if only I could successfully convert them. Unless I understand what I am doing wrong I don't stand a chance. So - start with the absolute basic Open/Close avi - This fails - Protected
memory eror
[Code]...
I can hardly think about streams til I can open a file, but when it is functional to the access to frames I'll submit a final copy for othersto use
how would I accomplish saving a large piece of data, using the Stream Reader for the Line-by-Line, while keeping the carriage return line feeds in there?
[Code]...
I am sending data to server via TCP IP Connection. I am using a continuous loop at the server end - that accepts new clients and while streams can be read, it reads data stream.
The data is sent from the client with 2 leading bytes of data that represent the size of the packet of data sent and type of data.
My question is: how do I retrieve the size of the data packet and then check that this amount of data has been retrieved?
[Code].....
I am sending data to server via TCP IP Connection. I am using a continuous loop at the server end - that accepts new clients and while streams can be read, it reads data stream.
The data is sent from the client with 2 leading bytes of data that represent the size of the packet of data sent and type of data.
My question is: how do I retrieve the size of the data packet and then check that this amount of data has been retrieved?[code]...
I need to read signed and unsigned 8 bit, 16 bit and 32 bit values from a file stream which may be little-endian or big-endian (it happens to be a tiff file which carries the byte order indicator at the start).I initially started by writing my own functions to read the values and was able to do so for unsigned values. e.g.
Public Function ReadUInt32() As UInt32
Dim b(4) As Byte
input.Read(b, 0, 4)
[code]....
But then I started looking at signed values and my brain broke.As an alternative, I found the IO.BinaryReader which will let me read signed values directly but doesn't seem to have any way to indicate that the data is big-endian or little-endian.Is there a nice way of handling this? Failing that, can someone tell me how to convert multiple bytes into signed values (in both byte orders)?
I'm trying to read an entry in an ini file; if it reads "ShowInvoiceRequiredMsg=NO" then my program is going to give the option to change that line to "ShowInvoiceRequiredMsg=YES". My code below reads the file and picks up if the option is set to 'NO' but I can't seem to modify that line to change it to 'YES'....... (in red is where I'm trying to modify this text)
Dim file As System.IO.File
Dim reader As System.IO.StreamReader
Dim line As String
reader = file.OpenText("c:file.ini")
[code].....
I have a CSV file with many rows in which I need to update/replace column four's value using VB.NET. There are no headers on the columns so the loop can start on row one.
infile.csv
"value1","value2","value3","value4"
After much googling, there are lots of examples on how to read and write CSV files, but none quite what is needed. I know there are multiple ways to accomplish this task, but a requirement is that it's done with VB.NET.tFinal code ported from Marco's C# answerPrivate Sub CSVmod(ByVal strFileName As String, ByVal newFileName As String)
Dim strLines As String() = File.ReadAllLines(strFileName)
Dim strList As New List(Of String)
Dim strReplace As String = "test"
[code]....
I have an application using Visual Basic 2010 Express. Basically I load an XML file into a datagrid and then wish to modify it. Now the following code works fine:
Private Sub Modify_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Modify.Click
Dim da As New XmlDataDocument
da.Load(Environment.GetFolderPath(Environment.SpecialFolder.Desktop) & "/events.xml")
Dim path1 As String = "/calendar/event/title[text()='" & DataGridView1.CurrentRow.Cells(0).Value.ToString & "']"
Dim path2 As String = "/calendar/event/text[text()='" & DataGridView1.CurrentRow.Cells(1).Value.ToString & "']"
[Code] .....
Now the modify button does what it is intended to do as far as load the "title" and the "text" elements into the text boxes. However I want to load the other attributes into the text box. I.E. date, timeStart, timeFinish etc. Also, the just of this is to be able to modify an xml file without going into the xml file using a text editor.
I want to change the file from resources. When radiobutton"Put new namirnica" checked=true, by clicking on button "save", i want to open .txt file in resources file that is loaded into listview1 and fill with data from textbox1,textbox2,textbox3,textbox4,textbox5,textbox6.
else When radiobutton"modify existing Namirnica" checked=true,I wish that selected index from listview1, replace with data from textbox1,textbox2,textbox3,textbox4,textbox5,textbox6. by clicking on button "save"
Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
Dim a As String = My.Resources.Hrana
[Code].....