Reading And Writing To A File In Binary?
Dec 20, 2010
few weeks ago i heard my teacher say that it is possible to view any file as a binary array (1s and 0s). if this is possible to do in visual basic please let me know how. Also how would i go about writing an array of binary to a file? For example 01100001 in a .txt file would produce "a"
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Jan 25, 2009
Reading binary file from hard drive in VB and writing to database.
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Feb 1, 2011
I'm trying to read back a string that I wrote into a binary file, but it's giving me problems and I don't know what's going on. I open and read my file using the code below:
ifstream input([filePath UTF8String], ios::in | ios::binary);
int numStringBytes;
input.read((char*)&numStringBytes, 4);
[Code]....
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Sep 24, 2010
I'm trying to read back a string that I wrote into a binary file, but it's giving me problems and I don't know what's going on. I open and read my file using the code below:
ifstream input([filePath UTF8String], ios::in | ios::binary);
int numStringBytes;
input.read((char*)&numStringBytes, 4);
[code]....
There is a lot more to the file reading code, but it's proprietary and this is the part that keeps crashing. It runs fine loading the first two files, but when I try to open a third file, it crashes with EXC_BAD_ACCESS at the input.read((char*)names, numStringBytes); line. I don't see any reason that this should crash. I'm writing the binary files in VB.NET using the below code:
Dim myFS As New FileStream(savePath, FileMode.Create)
Dim encoding As New System.Text.UTF8Encoding()
Dim stringBytes() As Byte = encoding.GetBytes("++string")
[code]....
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Aug 14, 2011
I want to create a program that can read and write the data on a file... this file is game music file that contains all information of song, I already know structure and I can read it, I want program only read the level of song (if song is hard to play, the level is more high), I read the data using File Stream and Binary Reader :
Using fs As New FileStream(OpenFileDialog1.filename, FileMode.Open)
Using rdr As New BinaryReader(fs)
Dim seeker As String = fs.Seek(20, SeekOrigin.Begin)
[code]....
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May 25, 2011
I am working on a program that creates a "license" file. This file is expected to be binary, containing a name, today's date, a warning date, an expiration date, and a preference of Metric or Imperial units of measurement, and essentially authorizes programs to work until the expiration date is reached, before which the warning date notifies the user that the license will expire.For this functionality to be fully utilized, the dates must not be able to be easily edited so as to prevent people from setting the date to whatever they want and keeping the program. What I have now writes each field from a String or Integer into whatever the BinaryWriter class deems should be written when I use its "write" method.I have been experimenting with the difference between Big and Little Endian encoding, which is selectable in the form.
If the entered name has no spaces, the file looks a bit unreadable, but not enough. With Big Endian, most of the Expiration Date is still showing; with Little Endian, the other two dates are mostly visible. However, using spaces in the entered name changes the format of the outputted text quite a bit, making all characters deliminated by a space, and therefore incredibly easy to change. My apologies that I cannot actually show you what the files look like.Is there a better/more accepted way of storing this data?I would like the license files to work with existing FORTRAN programs, of which read unformatted files in the general structure I've detailed, but reverse-engineering this sounds a bit difficult from what I've read and my employer has offered to rewrite the FORTRAN files to accept this new license creation program if need be.
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May 4, 2009
I need to write data to a file, preferably in binary format, but I am unaccustomed with the concept. Where's the easiest place to get the basics? I could come here with a specific need, but I'm at the point right now where I am more willing to work within the confines of keeping it simple.
Here's what I know:
1. how to open a new file
2. how to specify the record length
3. how to close the file
Some specific questions:
Does the record length have to be constant throughout the file?
Can I read the nth record without reading the whole file?
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Jul 30, 2010
I am fairly new to vb.net but was programming a long ime with vb6 I have a binary file that is a mixture of numbers (integers and doubles) and strings, such as "Programming with VB". I read the numbers using the BinaryStreamReader.ReadInt32 and BinaryStreamReader.ReadDouble, which are no problem
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Sep 29, 2010
I am doing some exercises on encrypting data. One of them are binary files. I am currently using triple DES to encrypt and decrypt the files both in VB.NET and C#... Now the thing is, once it is decrypted in VB.NET and saved, I can execute it again... But for some reason, my C# file is bigger! 20,4K where VB.NET one is 19,0. The C# file also is rendered unexecutable...Upon a closer look. The files appear almost exactly the same, but C# seems to add in a few extra bytes here and there in (seemingly) random places... I am currently using:
File.ReadAllText(String filepath, Encoding encoding); with UTF-8 encoding.
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Dec 1, 2010
Here is my code for reading a Binary file:
Dim fs As New FileStream(filepath, FileMode.Open)
Dim str As String = ""
For d As Integer = 0 To l - 1
Dim byt As String = Hex(fs.ReadByte()).ToUpper
fs.Position = d
str+= byt
Next
str becomes:
20202CB962AC5975B964B7152D234B
But when I open the file in a HEX editor, it's:
202CB962AC59075B964B07152D234B70
Why are the 2 different?
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May 4, 2009
I'm new to VB and trying to figure out how I can replace a bit of descriptive text in a binary file. I presume its binary as I cant open it with anything but a hex editor. I've changed the text (file description) in the hex editor and saved it fine but I'm unsure how I go about saving just the section of information I need. I can work out the saving bit later.In the attached file you'll see the highlighted bit I want to edit. I need to replace the whole line or the file corrupt but I can fill it up with null characters and the numbers are just
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Feb 19, 2010
I am attempting to read a series of double prcision float values (x,y,z coordinates) from a binary file using the binary reader. Everything works fine except that when I read the number back it is different then the number that was written there (original file is generated by mining application).
written number : 78897.6476586
file contents hex : 40 F3 43 1A 5C CF 43 A4 this converts back to the same number as written using a IEE 754 conversion program. VB returned value : -5.45100266729248E-134 using .readDouble()
I have tried to step thru the file in one byte steps to make sure that I have the proper start position but that did not help any.
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Jun 27, 2011
I have a tab spaced txt file that looks somthing like this;
[Code]...
I'd like to be able to read in the file and have a pop up message ask somthing like this; "Is cash1 for comp1 correct?" If yes ask about the 2nd line and if not ask what the real cash total is and then over write that to the file, then ask about the 2nd line.
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Dec 31, 2010
i am working on a Yahtzee projeect for college and am struggling with reading and writing to a csv file the code i have to read the file works but only gets the first column and displays it on a line not as a list.
Private Sub HighScoreFrm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
[Code]....
the other criteria i have to work towards and wondering if anyone can help is to limit the amount of records to 10 so need to check what the lowest score is and if the current score is higher over write it,
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Aug 7, 2009
I have created a small game for my son and after each game it tells him his score.all I want is to write the highscore to a file and have it open each time he begins a game..so he can see what his last score was. I dabbled with all this Io.file stuff and I just can not seem to get it to write to the file..also how do I work with app path in this case? I mean when the game is done and installed the current path of the save text would change.
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Dec 18, 2011
I must search a binary string for a pattern. This worked fine in VB6 using Get to read a file into a string and using InStr to search for the pattern. The conversion from VB6 to VB.NET changed Get to FileGet and warned of new behavior, but I don't see anything in the FileGet documentation about not being able to read 0 value bytes.
I don't mind at all changing to a new method, but ultimately I must get the data into a string rather than an array.
[Code]...
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Mar 15, 2011
I'm trying to write a program that will read a text file, and sort of filter out some things into some new files for myself. I have a website that I like to put information such as Artists, and songs for music. My website writes the Artist, and Song I input to one file on a new line in the format of (Artist - Song). The problem is it's gotten massive! I want to start organizing my artists, and songs anyway I come up with but I don't even know where to begin. To narrow it down I want to go into the file grab the artists name before the (-) and then write it to one file. After that I want to write everything after the (-) which is the songs to a different file. What file reading, and writing method should I use? As you might be able to tell I'm quite the noob.
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Apr 4, 2009
I have Strings writen to a file.
But i then want VB to read the file, and input ALL the strings in that file into a ListBox.
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Nov 23, 2011
how to read and write a text file in vb.net
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Mar 28, 2010
How would a person read a line of a text file by the number of the line. In other words, if I wanted to get the 3rd line of the file, how could I store that third line in a variable. While I'm at it, I might as well also ask how to do the opposite, or write text to a specific line (in this case, writing over the other information on the chosen line).
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Jun 30, 2010
Ok so there is an XML file for a program that already exists that stores a list of files along with other information.I need to open this file and read the file names and then potentially add files to it if they DO NOT already exist in the file.It is very important that I not wipe the XML file and have to write it from scratch every time.
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Jan 30, 2011
I am trying to write the TOURN structure and then read the TOURN structure back in.. the file gets created on my desktop and the program does not have any syntax errors, but when I READ the file none of the Data gets retrieved. So I am not sure if the DATA was actually saved or it is just not being retrieved?? This is what I have coded so far...
[Code]...
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Oct 7, 2009
I'm using visual basic 2008 express to do some simple stuff. For this project, Im reading in one large text file.The top of each page has a header section that is always the same, except sometimes a dept# changes, signifying a new set of data.The first line always has the text "RunDate", so when I read that, I know that I'm at the top of the first page.After reading the first line, I'd like to immediately go to the sixth line and grab that dept# and store it.dept = left(trim(myline,7)(Its always 7 characters long) so I know what dept I'm working on.I'll then loop through and write each line to a new text file, until I hit the top of a new page.At that point I need to look at line 6 again. if the dept # is the same, I'll keep writing to the same file.Reading and re-writing from the text files is easy, I just loop through line by line, but I need to be able to jump down to the 6th line, and I don't know how to do that without reading each line to that point"
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Sep 28, 2009
The program that I am writing has three default variables that I would like it to store and also be able to change. I have them in a text file called "settings.txt" The format of the text file is as follows:
Default Source "I:DCIM101MSDCF"
Default Destination "C:Documents and SettingsChristyMy DocumentsMy Pictures"
Default Backup Destination "D:My DocumentsBackupMy Pictures"
The field descriptions eg "Default Source" take up 30 characters, so the variable data starts with character 30. I know their has to be an easy way just to pull out the data from a particular line starting with character 30 but I can't find it.
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Mar 25, 2012
I'm writing a program where there are text boxes and the user can enter info and append them to a text file as well as read from the text file and view the various entries in it. The problems I'm running into are that I have a button that opens an open file dialog box allowing you to select the file, and I want to get it to open the first entry of that file in the correct text boxes. the code so far looks like this
code:
I used to have this bit of code in there but there was a conflict with the .txt file being used more than once at the same time while it was in there.
code:
Im also having trouble writing to the file and I'm not sure why. I have an "Append" button that has this code in it
code:
and it comes up with the issue "object reference not set to to an object instance".
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Aug 18, 2009
I have a 2 text files
Text file 1:
.ERR - Max6 Error file
[2 19.40 44.7] X6.950 Y-4.705 106.522, 222.048
Open -106.522, 222.048
[2 05.52 39.6] X7.720 Y5.010 214.550, 205.048, 101.078
[code]....
But it not writing anything as output..
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Aug 18, 2009
I have a 3 text files
Text file 1:
.ERR - Max6 Error file
[2 19.40 44.7] X6.950 Y-4.705 106.522, 222.048
Open [code]....
From here i have to read the Node name which is MEM_B_DQ7.Then match node name with third file and get that node name group
Text file 3
NODE MEM_B_DQ7
PINS
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Aug 17, 2009
I have a 2 text files
Text file 1:ERR - Max6 Error file
[2 19.40 44.7] X6.950 Y-4.705 106.522, 222.048 Open -106.522, 222.048
[2 05.52 39.6] X7.720 Y5.010 214.550, 205.048, 101.078 Open -214.550, 101.078
[2 07.69 39.2] X7.786 Y3.489 215.574, 214.075, 204.067
[Code]...
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Nov 11, 2011
This is what i wanna do and dont really know how:
When i click button "StoreX":
if X.ini does not exist it will be created at the same folder as application
NumericUpDown1 value stored at X.ini line 1
[code]....
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Dec 3, 2011
Their is a problem whenever I want to write something to a text file. Please see the attatchement to see what happens when I'm debugging. I've put the code for writing to file right at the end of the program.Here is some of the code which shows how the program writes to and reads from the file:
Option Explicit On
'Force all variables to be declared.
Imports System.IO
[code].....
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