Binary -store/retrieve Bit Data From File Using BinaryWriter?
Apr 11, 2012
I need to store/retrieve a bit from a data table of 3.268.760 bits long.
Using w As New BinaryWriter(File.Open("test.bin", FileMode.Create))
for x = 1 to 3268760
For i = 1 To 3268760[code]....
the w.write(?) stores a boolean value meaning 0/1 for false/true values, but Vb.net seems to use an whole byte to store this data which is too expensive for my table (3.268.760^2).Is there a pratical way to store/retrive single bits from a file using vb.net? (meaning as little as possible conversion to other types).
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Oct 8, 2009
I am using BinaryWriter class to write a binary file to disk. When I invoke the Write method, passing an unsigned short value, it writes it in little-endian format. For example:
bw.Write(0xA000);
writes the value in the binary file as 0x00 0xA0. Is there a way to make BInaryWriter use Big Endian? If not, is it possible to create a new class, inheriting BinaryWriter and overload the Write function to make it write big endian?
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Mar 29, 2010
I'm trying to build something called a structure which will store data it retrieves from a text file. I have the structure set up like this:
Structure Employee
Dim FirstName As String
Dim LastName As String
Dim ID As String
Dim Hours As Integer
Dim Wage As Decimal
Dim EarnedPay As Decimal
End Structure
[Code] .....
How to set these operations up?
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May 22, 2012
I want to store data in binary format in VB. Are there any disadvantages to use the functions fileopen, fileput, and fileclose instead of serialization using binaryformatter object. Using these functions seems to be easier and more compact.
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Feb 8, 2012
I like the PHP way of doing things but, it seems I am stuck with using a Collection of Object's to store/retrieve the data I need. I have my Collection loaded with my Objects's and the code to iterate through the collection, my problem is I am unable to retrieve the "key" as it would be called in PHP (I believe in this case it is actually the name of the object).
Consider the following example:
Dim xDoc As XPathDocument = New XPathDocument(fName)
Dim xNav As XPathNavigator = xDoc.CreateNavigator()
Dim sender As XPathNodeIterator
[CODE]...
As you can see, I am navigating an XML document, and creating an Object with some Key/Value pairs. The Object would look something like this if it were in JSON:
{"name":"John Smith","address1":"123 Anywhere St.","city":"This City","state":"FL"}
When I iterate though the Collection I can only get the value of the object, but I need the Key, in this instance I want "name","address1","city","state" to be stored in a variable for each iteration.
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Dec 16, 2010
If you have to store and retrieve data from a database is a string not the most effcient way? What is best?
How does this work in a real world scenario.
For example: I have a customer ie first name and last name and the CustomerID is autoincremented when initially added to the database. Now, the user could lookup and find the customer by their ID but we all know that's not practical. They don't know 231223 is John Adams, they know John Adams or Adams John.
So how do you handle this? Access is the database I am using but I think this would apply to any database.
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Aug 10, 2009
I have a process that's going to initially generate 3-4 million PDF files, and continue at the rate of 80K/day. They'll be pretty small (50K) each, but what I'm worried about is how to manage the total mass of files I'm generating for easy lookup. Some details:
I'll have some other steps to run once a file have been generated, and there will be a few servers participating, so I'll need to watch for files as they're generated.Once generated, the files will be available though a lookup process I've written. Essentially, I'll need to pull them based on an order number, which is unique per file.At any time, an existing order number may be resubmitted, and the generated file will need to overwrite the original copy.
Originally, I had planned to write these files all to a single directory on a NAS, but I realize this might not be a good idea, since there are millions of them and Windows might not handle a million-file-lookup very gracefully. I'm looking for some advice:
Is a single folder okay? The files will never be listed - they'll only be retrieved using a System.IO.File with a filename I've already determined.If I do a folder, can I watch for new files with a System.IO.DirectoryWatcher, even with that many files, or will it start to become sluggish with that many files?Should they be stored as BLOBs in a SQL Server database instead? Since I'll need to retrieve them by a reference value, maybe this makes more sense.
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Jun 12, 2011
How do you store data in the access database and also to retrieve it? and also a search engine for the database?
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May 15, 2009
I have a connection string in my database which I read throughout my VB .Net application. I have another string which is NOT a connection string though. It instead has information about a domain on LDAP. So LDAP string just needs to be stored in the web.config as a string, and also to be retrieved as a string.
[Code]...
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Mar 19, 2011
I am after some simple code to retrieve a txt file of a server (http) and store it in a string.
I have had a look around, but non luck.
I am using VB2010 on Windows 7
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Dec 4, 2009
am trying to store and retrieve data from a closed excel worksheet while in a form created in vba studio express 2008?
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Aug 27, 2009
I am using VB2005 and trying to put an application together.What it needs to do is retrieve information from a binary file, possibly alter that information, and put it back into a new file.The file is a .wav file with data appened to the end. There is an additional section at the end of the .wav file which stores xml data.I have found that if I open this in a hex editor and make a 1:1 swap on any of the bytes that the application that the file is for can still read the XML.If I tried to add or remove characters from the XML then it would not read. I located a header byte and incremented it to resolve this.
This worked as an excellent bandage to do conversions where the data always needed to be changed to the same thing.What I have been asked to do is build logic that allows for different things to happen depending upon what data is contained within the file.The method that I am currently trying to impliment is:
Read through the file with a system.io.binaryreader
Searche for a bytestream that will signal data is coming
For example:
If System.IO.File.Exists("C: est estread.wav") Then
Dim findit() As Integer = New Integer() {&H3C, &H55, &H73, &H72, &H44, &H65, &H66, &H30, &H31, &H30}
Dim i As Integer[code].....
And then extract all the data till the end of element marker "<" It seemed like there should be a better way and I was looking for some insight. If I proceed with this method, I will have to read the file one time to gather the information and then a second time to write it all out with the header modified for length.This is my first experiene with working with binary files in this way.Also,I've been experiementing with building a string and slapping it back in at the end using the binarywriter.write(string) method.I noticed that it was putting in header characters before the string.These seem to change if I change the length of the string.At one point it was d0 07. Later it became e7 07. Does anyone know of a way to prevent this header from being inserted?
I tried a for each loop to grab all of the characters from the string, convert them to a byte array and deposit the byte array into the file, but the header remained the same. When I write the byte array generated from a system.io.binaryreader I do not get this header.
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Oct 21, 2010
I have function on client side that get file, make a byte array from it and send that array to the web service on server!This is the function on client side:
[Code]...
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Mar 5, 2011
I created a subroutine to copy and paste a file using the binaryreader and binarywriter. It works fine from what I can tell. The file sizes match up any how but I was wondering if anybody had an idea on a better way to get the amount of bytes that should be copied in one set.
binwriter.Write(binread.ReadBytes(100000)) I want to make the readbytes as large as possible without crashing the users computer.
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Feb 23, 2011
I have been googling this and have not come along a working solution for an entire day. I don't know anything about binary data types (as I've never knowingly used them) and I'm trying to write a binary value that I see in the registry, to the registry. Now, all I see is the following [shown below]... and if I try to pass that as a string to the RegSetValueEx in the WinAPI and of course it errors out...
I do not know what 'numbers' I need to pass into the lpData As Any, argument of RegSetValueEx (i tried a bit array) in order for it to come out as the following [shown below] in the regedit. I really have no idea, and my tests to place random numbers in the bit array just produce corresponding random "figures" as visible in regedit that I do not understand how to 'tie' them together logically. here is the culprit!
[Code]...
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May 3, 2011
I have a VB.NET dll which pulls out binary data from and opens it as a pdf. It works fine if I create a file on the user's machine and then open that. What I want to do, however, is just open it in Adobe without creating the file on their machine first (there's customer data in the file and we don't want copies of it sitting around unecessarily).
It's possible in ASP.NET to just stream the data to a browser and open it in that without creating the file, but I can't find a similar methodology for doing that straight to Adobe. Does anyone know if this is even possible or do I have to create the file in order to have it open?
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Jul 21, 2011
I'm a beginner programmer, but this may not be a beginner program question. I would like to write a program in small basic or visual basic that reads data from a binary file. The data are formatted in hex and look like this:
[Code]...
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Mar 21, 2008
I'm designing a very simple program that will need to save both data and photos to a cd but my code refuses to let me do it. Here is what I have:
FileOpen(1, "E:FileWithData.dat", OpenMode.Binary)
FilePut(1, AString, 10)
I keep getting an incorrect function at FileOpen
I saw some methds which take numerous lines of code but I like to keep my code very simple so I can easily tell what it does.
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Sep 11, 2009
I am new to VB.net. I want to read and input file and store that data to an SQL Server database. Do you have an sample code that do such?
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Oct 11, 2009
I want to create a pdf file from Binary data. I looked around and found examples using iTextSharp by fetching data from the database.[code]...
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Jan 11, 2010
I have a jpeg file in my C drive from my vb.net application I want to binary read it and store it in SQL server.
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Feb 9, 2010
I have a binary file. If I look at it with a hex editor, the first values are:208, 207, 17, 224, 161, 177, 26, 225, 0, 0, 0, ... etc.It has a length of 330240 bytes I have tried to open it and read it into a string so I can manipulate it and write it back. No matter what I use, I either don't get the correct number of bytes or the values in the string are incorrect. The most common error results in the first values being: 63, 63, 17, 63, 63, 26, 0, 0, 0 .... etc.It is interesting that it appears that any value > 63 becomes 63.
I get the 2nd values by a simple loop:
For lnx = 0 To 99
Debug.Write(Asc(line.Substring(lnx, 1)))
Next
I have tried a whole number of ways to read in the file, including filestream, My.Computer.FileSystem.ReadAllText, File.io.readAllLines, etc.All either give me a string length of about 324000 (not sure why) or, if they do, don't have the correct values. Yes, I have tried various encoding options.
I need to find a string (sort of like: "D" & Chr(0) + "L" & Chr(0) + "S" & Chr(0)... ) so I can then replace that portion of the string with a new value, then write out the file.I use the ".indexOf" to find the data in the string.Why can't I load the file into a string? Or, do you know of an easy way to find some text (similar to above) in a file and then replace the next x number of bytes with a new value and close the file?
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Sep 5, 2009
I'm having problem reading Binary file that has two types of data in it; Strings and numeric data in decimal format.[code]...
1. The loop doesn't stop, and it gives me "Unable to read beyond the end of the stream" Error..
2. The output isn't accurate, apart from a few random correct strings and numbers..
3. After the loop is fixed, how can i save the data to an Array or write it to a text file?. Can the be saved line by line so that the output file has the same number of lines?
4. As you can see in the code, I've tried writing data in a file, but it doesn't work.. Messagebox does show some data (even though it's not accurate), the file however doesn't contain any data..
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Apr 29, 2010
How would I use the BinaryWriter to append binary data to a file that is very large? Say a file that is 3GB in size. The BinaryWriter's write method will only accept an integer for the index value. I've attached a screen shot of what I'm talking about. If I were to enter a value that exceeds the size of an integer on my 32bit Windows XP system, which I believe is 2147483647 it will reject it right?
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Aug 8, 2011
how to store pdf file in data base using visual basic?
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Jan 4, 2010
I am retrieving data from a csv/txt file using oledb driver
ConnString = "Provider=Microsoft.Jet.OleDb.4.0; Data Source = " & System.IO.Path.GetDirectoryName(strFileName) & "; Extended Properties = ""Text;HDR=YES;FMT=Delimited"""
strQuery = "SELECT * FROM [" & System.IO.Path.GetFileName(strFileName) & "]"
In the last line I am getting following error if the filename is large
Is not a valid name. Make sure that it does not include invalid characters or punctuation and that it is not too long.
My question -
Is there any limit to filename or the select query or there is some pattern which I need to follow?
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May 24, 2011
I have a data in the below format
number = 4
length = 7
force = 100
Now I want to read it in a format that it will check the string 'number' or 'length' or 'force' or whatever and stores this data into specified arrays or listboxes. Like a force() array or listboxforce.items()
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Oct 27, 2009
I have a question (suppose to be simple). The question related to reading text file which is in the below format.
[Code]....
What I want here is to store the first data column in the file to be stored in AreasString and 2nd column in Level, 3rd in Importance and so on untill the end of the data. In addition, How can I check the type of data? For example, if I want to say: If 10.25 is double then msgbox ("it is double") else msgbox ("it is integer")
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Mar 17, 2011
i have created one access file but i got error in the code so i can't store the values in that data file please check my code what's wrong with my code. [code]
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Jul 14, 2009
I have an asp.net/vb file that receives data and processes it via a stored procedure. The code had the width set to 2 for the year's varchar, so it was chopped, leaving only the first two digits to get inserted into the db.Is this info possibly retrievable from a system/IIS log file or is it lost forever?
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