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?
View 4 RepliesI am trying to develop an application that will let me do the following
1) Be able to search to large binary files for a specific byte array (header) and to continue searching for another byte array (footer). Then i want it to copy the section of the binary file between these 2 locations to a specified file. Then the program is to continue searching for any other header/footers An example would be search a large file and carving out the jpgs it finds etc. This routine would have to be able to handle raw images of 20gb or more if needed.
Is there a quick way of finding a character?? I have this error
Invalid character in the given encoding. Line 1, position 7173.
Eak, I need to know what this is but don't really want to count across 7000+ letters
I've gone through about 16 hours and two packs of cigarettes trying to figure this out. First a little background. I was using 6.0 up until 2004 when I went to prison. I'm out now, and trying to relearn the trade, using VS 2005. I'm currently porting some 6.0 code from another project, SpyCast Webcam Studio, into VB 8.0. It's disheartening, to say the least. None of the old built-in subs/functions work anymore, so I have to scour the forums to relearn each and every function.The section I'm doing now takes a snapshot from the webcam (Video API --> PictureBox --> Save as Jpeg), then upens the file to upload it to the server via HTTP POST. I've been using this code in SpyCast for years with no trouble, but I spent many hours trying to piece together the right code to open the binary file to read its contents. I pieced together two methods I found around the forums, one using FileStream() though the code I found wasn't for binary files, even though it said it was, so that code doesn't really work. Method two uses Microsoft.VisualBasic.FileOpen() and works better.
By the time I run through the rest of the rigamarole of uploading the file, by the time I read it on the webserver, it's *slightly* corrupted. It's a valid Jpeg, no errors, but the picture looks like when I use to watch the Playboy Channel when I was a kid....scrambled with weird colors and whatnot.Each "chunk" is basically one "line" of the file. It looks like a single LineInput() return is the text between two carriage returns. Am I correct? I tested this with a flat text file, and it looks true. However, That one input line returns the text or data with the carriage returns *stripped*! ***?!? =( Fine, I have no problem adding my own vbCrLf to each LineInput(), if I were opening text. but this's binary. A character could be Chr(10) or Chr(13), both of which are removed from the original file contents.So I could very well need to use something other than LineInput(), but I haven't found any other examples on the web using this method. Posting the question in a forum was my last resort, because I hate...y'know, asking for help. It's a man thing, I guess.
Is there an easy way to insert a line into the very beginning of a large file?I want to insert an XML header line into XML files that my program processes (These files can be very large, so reading it via bitstream and writing it out is not a good option).
File.AppendText makes it very easy to append lines to the end of a file, but I don't see anything for inserting text.I wonder how does say Access work in processing say a 50 meg access database file? There must be a similar process where you can insert data anywhere inside a large file.
I need to make an E-Search engine for collage library , i can make it by using streamReader and streamWriter , but unfortunately i have to use Binary to make this project ... i've to many fields to put it on DAT file , and i've to use SPLIT to split lines and make arrays ..
what is the best way to do that ? how can i write an opened binary file on textbox and convert text to array ?
I'm appending string variable text after appending a line throws System.OutOfMemoryException?
Can any one explain why it is throwing error.
str+="something Text"
str+="something Text"
and lastly I assign it to a lable text When I assign the value of str it throws exception.....
I have some functions written in C that read & write large binary files (> 4 GB) using routines CreateFile, ReadFile, WriteFile & SetFilePointer, that use the HANDLE data type to access the file. Some others who are more familiar with Visual Basic would would like to be able to call my C routines to work with such large binary files. We particularly need SetFilePointer to jump around with the files.
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Couldn't think of a better title.(Background on the problem/me)Okay, so, first question/post here, so hi. Now that that's done with, the information pertinent to my problem. I'm fairly new to VB (and programming as well, aside from screwing around with C++ and learning assembler(well, attempting is the better word) god knows how many years ago), and have only seriously been programming for about under half a year, and my skill level is about at that stage. Only been using VB.Net, nothing older. Depending on the time of day and if I'm home or at school, I fluxuate between VB express and Vis Studio 08. Umm, this program I'm having trouble with was on a test that I took yesterday (took the problem home with me cause I really wanted to figure out what was wrong with it).
The stipulations of the test were:
No For->Each Loops
No using Built-In Sorting or Searching Functions
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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]...
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?
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:
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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.
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]...
View 1 RepliesI 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).
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?
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..
I would like to know how it's possible to append text between data.
For example:
I have a RTB with "ABC" on the first line and "DEF" on the third line. My question is how would I insert text data into the second line, without changing any existing data.
I am trying to save the contents of a richtextbox to a text file. I know that they .SaveFile method automatically overwrites the existing file so I have a routine that will load the contents of the file into a temporary rich textbox control then append the new information to that and then save from the temp richtextbox. My application works as I want it to on my workstation but I cannot get it to work correctly on the notebook computer it will be running on from now on. It only works when I put in a breakpoint and I am not sure why?
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If I put breakpoints on any of the lines rtb.Select, rtb.Copy, rtb.Paste then it works. I even tried putting a Thread.sleep before saving, thinking that more was needed to do the copy/paste but that didnt work either.
Lets assume I have a DataSet that contains the following info (columns seperated with | character):
1 | Logan | Young
2 | John | Doe
3 | Jane | Doe
4 | Joe | Soap
If I now write this info to a text file, but later want to append 5 | Susan | Sarandonto the end of the text file, I obviously want to check that the text file doesn't already contain the data that I want to append to it. I'm having a little difficulty figuring out how to perform this check...I know you'd have to loop through every row in the DataSet's table and compare it to every line in the text file. That part's easy.
We are trying to Open a text file and if our needed information isn't in there, we need to write it, otherwise we need to append to the existing text. We had it working in VB6 (below) and i havent the slightest clue
CommonDialog1.Filter = "Text Files (*.txt)|*.txt"
CommonDialog1.FileName = frmSplash.fp & "\job_info\" & nam
Open (CommonDialog1.FileName) For Append As #1
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I am having a hard time trying to append to an XML file I create. This is currently the code I have to create the XML file:
[Code]...
My user can export a ".doc" file but when VB.NET writes to this file it uses "" and "," characters at the end of each sentence. I was wondering if there was a way of actually appending the exported file to remove these characters?
View 8 RepliesI have a VB 2008 program which shows the user's results in a ListView, and permanently stores them in a Notepad (.txt) file. The program works fine when I run it using Debug. The permanent records show up on a .txt file in the "bin". However, I want to publish the program as an executable file. I have tried this using my normal method of selecting "Publish" from the "Build" menu, and my program runs fine but there is no .txt file to be found.
View 3 RepliesStuff like this makes me hate computers! Anyways, I'm again struggling with something relatively simple - or so i thought.I have a sub:
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Then, I have a sub that runs every minute, calling yet another sub, which calls this one. Before you say whoa! that's too many, I'll say that each of these subs has a different purpose.The whole problem is that the WriteToFile sub writes only once to a file! Instead of continously writing to the file every minute, it stops at the first line.
I have a resource file that is a dictionary.txt file, which is basically a list of 100,000 odd records. I want the user to be able to add new words to the resource (which will be embedded in the final build).I can find ways of adding records to files e.g.[code]But how to i write new records to an embedded resource file?
View 2 RepliesI am creating an xml file if it does not exist, but am having trouble with appending to the file if it does exist. I am using the reference System.Xml Here is my code:
Code:
Public Function App_Path() As String
Return System.AppDomain.CurrentDomain.BaseDirectory()
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I have a piece of software that can be used either on an admin account or a standard user account of a completely stand-alone, Windows XP machine.
I have also set up some log files that the system uses when it either performs an admin function or if an error occurs. the location of these files is a C: location - not (from what I can see) associated with the admin account in any way.
When running the software from the admin machine, the log file is appending fine. When running the software from the standard user machine, the log file causes an error, suggesting that "Access to the path 'C:HNP MTWP Log FilesAdministrative ToolsAdmin.log' is denied.
This error occurs when first setting up the FileStream. Here is my code.
Imports System.IO
Public Class Log
Private Const cnDirectory as String = "C:HNP MTWP Log FilesAdministrative Tools"
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Is it possible to append text to a text file located on a webserver from a winform? If so, can you please point me in the right direction. I've searched this forum but can only find documentation on appending a local text file.
View 2 RepliesI have a several text files that get updated each month - when they are updated certain lines are missing that I always want adding back to the files - the text I want adding back needs to go into a specific part of the text file(its always the same text that needs adding and same location)
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