File I/O And Registry :: When To Close Files
Jul 24, 2010
I should mention that I'm mainly concerned with Random files.Which is the best method?
1.) Open file, manipulate data and immediatly close the file. (Which means doing this alot everytime data needs to be read, edited, deleted, or saved)
(2.) Open the file when the app starts and let it open for data manipulation until it's time to close the app at which time the file would be closed.
I was always taught option 1. The main reason at the time was to cut down on the chance for data corruption in the file or an outright loss of the file due to outside circumstances like power failure.
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Dec 11, 2011
I wrote a program to download and play AVI files the files are large in size and long time wise. I have the files playing as they are being downloaded but i can't see how long the file is or seek reliably. i was reading that the AVI headers are in the last 512kb of the AVI file *why would't they put it at the start* lol so my question is is there a way to download the last 512Kb of the file i'm downloading. i have the Bytes Read and Length of the file while its downlaoding i'm just not sure where to go from there, or how to do it atleast. If i had the length in time of the Avi file i could set the trackbar to be able to seek properly. or if someone has an idea how i could get the time of the video by using fps and some math i could prob do it that way too but idk how i would tell how i can find how many kb are in the fps i'm sure it changes so think that way is't going to be reliable. how to get the last 512kb would be the best option not sure if it can be done even.
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Feb 9, 2009
I 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!
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Mar 27, 2009
I've got an app which uses a background worker to copy files. It works fine but some files are quite large and it "appears" as though the app isn't doing anything. Is there an alternative to the File.Copy method of copying files so I can report on the progress of individual file copies, like the percentage complete?
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Jun 2, 2009
Looking for an idea of where the best place to keep files for a program. I use them frequently and they interact with the program directly. I want to place them in a place where they won't be easy to find if someone is just cruising thru the directories. Any ideas?
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Sep 6, 2008
I'm new in vb.net (application). I need to access files or browse files using vb.net. Does anyone knows how can I do it?? I can use the listview??This is the process:I have a form and I need to browse folders and drivers (C drive/network drive...) in the same form. But how can I do that, how can I display the icons, file, etc. and open it in listview or any control in vb.net.
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Jan 19, 2009
Is there a way to get a list of files in a certain directory and then put them in a context menu strip then when they are clicked have the program open the file. I'm trying to make a flash player that can show the list of flash files and when you click the file path on the context menu strip it will play from that file. Here is what I have:
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
OpenFileDialog1.Filter = "Shockwave Flash Objects (*.swf)|*.swf|All files (*.*)|*.*"
[code].....
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Jan 25, 2012
I'm programming a small windows app that allows the user to fill out some fields and then creates and runs a batch file based on their entries. The program works, but it doesn't.The program creates the batch file just fine but when it tries to run the batch file, it gets errors in the cmd window saying it cannot find the scripts the batch file is trying to call. What's confusing me is that if I take the batch file the program created and run it myself, it works just fine so I know it is not the batch that is the problem. My best guess is that there is some security setting for vs.net that I've overlooked but I am only an "every once in a while" programmer so I really don't know where to look. Additionally after running the batch, the program is supposed to delete the batch file but that fails as well with the message that it cannot find the batch file, the same batch file that it had just created and run.
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Dec 10, 2008
have just started vb .net and im working with the 2005 edition, but i would now like to make a program that i can use at home that will alter files names,Bassically where i rip cd's to put them onto my mp3 player they are always given a name starting with 01. etc, what i would like is a small bit of code that uses a while or for loop to go through every file in the folder and remove the first three characters.
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Sep 25, 2009
I'm trying to keep the oldest file and move the new ones to a different directory
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Nov 2, 2009
how to read and write random access records in .NET. Now I know random access files are dead and the response on every query I found with google/bing/yahoo searches was don't use random access use Binary serialization but I can not. I have a situation where I need to read and modify 256 byte records in a file that is used by another application.
Now for a bit of background the file is made up of 27 fixed length records of 256 bytes. Each of the records has a separate structure consisting of 30-120 fields. The proplem I am having is I can create the record structures but when using the FileGet method I am receiving an error. Now I have found samples that showed the same format I am using that claim to work.
The error I am getting is Option Strict On disallows narrowing from type 'System.ValueType' to type 'ProgramName.ModuleName.Record' in copying the value of 'ByRef' paramater 'Value' back to the matching argument.
The basic layout (simplified) is as follows:
Code:
Structure Record
<VBFixedString(6)> Public SomeParam as String
Public SomeNumber as Short
[Code]....
Now the overloads for FileGet show all of the data types including Object. But I have tried various methods to retreive the 256 byte record but without success. Do I have to actually read each of the several hundred fields of the structure one by one? Or am i overlooking something (I have been known for this in the past)
Or (and I'll kick myself if this is the only way) do I just have to set option strict Off in the module and the code as above will actually work.
I would love to be able to just ditch the random access file but I have to keep it for compatibility with several other applications at this time.
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Sep 1, 2008
Alright this is what im working with. Im Working with vb.net 2003.I have (X) amount txt files in "C:Marble".In each txt files there are 3 lines.I want to read the first line of each txt file and display them in a listbox. [code] Things i need to Find:
-1 How to tell how many files are in a folder
-2 How to create a loop were it reads the first line of each file in that folder
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Apr 24, 2009
An application that my company uses stores report files with a .dat extension for use with their software. These files can be opened in notepad and the basic report information can be seen as text. I am attempting to write an app that opens and reads data from these .dat files and displays it in a checked listbox. My hangup thus far is that I can't figure out how to read the data from the .dat files since they are not .txt files. Can anyone point me in the right direction?
[Code]...
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Jun 2, 2010
I know how to get a list of files in a local Windows machine's specific directory:
Dim dirInfo As DirectoryInfo = New DirectoryInfo("C:Temp")
Dim fileListing() As FileInfo = dirInfo.GetFiles()
But how do I use this class for a mainframe system where user ID, password and 'change directory' command are needed?
When I attempt to just access the server without credentials and just do the Windows version and use the syntax "\server_nameAUTO:RPTS.", where 'AUTO:RPTS.' is the mainframe directory name I get the following error: "The given path's format is not supported."
When I just use '\server_name' I get: "The UNC path should be of the form \servershare."
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Aug 28, 2009
I am using zipforge.net to archive files in a small backup program I am creating. Everything works fine however if I try to archive a large number of files the process of zipping them gets slower the further along in the job it gets.
Example: I have a directory that contains a little over 100,000 files in it. Each file is only about 200k of text. When I use the zipforge zip class it starts zip'ing very quickly but as it gets about 40% of the way through the directory it starts to slow down... at about 60% its working at a snails pace.
Memory usage for my solution also goes up proportionate to the archive file size as it grows. Currently it takes around 26hours to backup this directory which only contains 4 gigs worth of information.
If I use a program like winzip I can zip the folder in less than an hour. I am thinking there has to be a way to write to the end of the zip file without having to open it every time or without keeping it open. My backup software scans the specified folder and writes each file path and name into a text file. Then it reads the text file line by line and passes the path + file info to the zipforge addfile().
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Nov 20, 2009
For a project, I need to extract all the frames of an AVI video. This I have accomplished by with free program. The problem: it took a 30 second clip and spit back 5400 some frames, and the image only changes every 20 frames or so. I really only need about 270 frames, but I didn't want to go through each one manually. So, I wrote a small program using Visual Studio 2008 and VB to open each image in binary and compare it to the one before that. If there is a discrepancy of more than 55000 (to accommodate slight errors in capturing), it leaves the file be. If not, it deletes it.
After much troubleshooting, I got it all to work. I ran it on the directory containing the images, but when it finished, only the first image remained. I checked into it, and found that the FSO loop I have set up to loop through each file was pulling the files in apparently random order. It will give me the image "bg(01).bmp" and then immediately "bg(1362).bmp" and so on. And the order changes every run.
I tried setting up an array to generate a list of all the files and then sort them, so I could pull off the name of the file, then the next one, ect. but it took over 3 hours to finish processing the array, and then It was using a huge chunk of RAM.Is there some way to "force" vb to pull off files in alphabetical order? here is my, code, it belongs with a form. fPath is a global variable, simply pointing to the source directory.
[Code]...
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Jun 18, 2009
im looking for code to copy the files from the floppy drive to a removable drive on the computer.For example:
Copy A:contents to Z:contents
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Mar 28, 2011
I'm trying to copy multiple files from a directory, put them into an array, then copy just the 30 newest files(I haven't coded the 30 newest loop yet). I added a list box to the following code just to ensure the all the files are storing into the array properly... they are. When it try's to copy, it renames the first file to .log, then tells me that the .log file already exist. How do I get it to copy and keep the source file name in the destination folder Eventually I'll loop this and grab only 30 of the files.
Here's the code I'm playing with:
Private Sub transferButton_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles transferButton.Click
[code].....
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May 23, 2009
I can't find any way of loading all files with e.g (.txt) from a specific directory: C:UsersChristianDocumentsMy Logs I use Visual Basic 2008 .NET, this is how I try to get it:
1. When the form loads it should retrieve the full path and title of the files and then put them in the List View control.
2. When the user marks one file in the list view and then clicks a button the text content should be displayed in a multi line textbox.
[Code]...
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Jan 12, 2009
I need some help loading RTF files in a RichTextBox Control. The RTF file i have has a lot of textbox and some graphics. I tried several methods, but i cannot load the RTF file correctly.Here is what i have so far:
Code:
Private Sub btnLoadFile_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLoadFile.Click
Dim fn As String
Try
[Code]...
I suspect that the LoadFile method cannot read the TextBoxes in my RTF file, or maybe i'm missing something. Attached is the file i'm working on.
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Aug 23, 2011
I'm trying to return a integer / count of the ammount of files in the directory and sub directories in the 'Windows' folder, I need to be able to do this as fast as possible (no lag) and tell when it's done, hope I explained this right.
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Jul 15, 2009
I wrote a cleanup program to go through some directories and delete files based on if the creation date is older than say 6 months. It works fine with some of the directories I have that contain around a few thousand small files. However, there is one directory (that contains small backup files from another program) that is loaded with over 300,000 files and it locks up on me as soon as I read in the first file in that directory.I am convinced it is the directory has too many files in it to open it. The server that the directory is on is slow. It takes a half hour to open the directory while on the server itself. I know it will take forever to delete the amount of files I want to delete, but I don't understand why it gets stuck and hangs there with no error message.Here is where I get stuck. Listbox1 is the directory I'm attempting to access
For Each selectFile In My.Computer.FileSystem.GetFiles(ListBox1.Items.Item(Count), FileIO.SearchOption.SearchTopLevelOnly, "*.*")
compFile = Path.GetFileName(selectFile)
[code].....
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Aug 14, 2008
I require some help in saving and reading files in Line by Line format, How would I save to a specific line in the text file, or read a specific line?
[Code]...
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Jul 20, 2010
I found this code on here to open a text fille, do a find & replace then save the changes, and the code is in a loop that will do that to every file in a given folder. My question is I also have files in sub folders, and more sub folders, and i'm not sure how deep it goes. I want to recursivly go though all the sub folders and do this to all the files, not just the files directly in the main folder.
Here is the code so far:
Code:
FolderBrowserDialog1.Description = "Select Path for files to edit"
FolderBrowserDialog1.ShowDialog
OpenPathVariable = FolderBrowserDialog1.SelectedPath
[Code].....
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Jan 16, 2009
I'm currently in the process of building a text editor type program, and have run into a brick wall. I haven't done VB in years, so I may just need a little reminder on some things. I have coded everything so far as far as opening files, saving them, changing fonts, colors, etc. However, I'm looking to add a Close button to my menu strip that will just close the currently opened file, and not the entire program, while also ask the user if he/she would like to save before closing the file, and then if they select yes, it will show the save dialog, and if not, it will go ahead and close the currently opened item.
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May 8, 2010
I am trying to find a way to allow my users to choose the directory to save files into, THe file name is automatically generated as it has a naming convention and i am able to pre program a location to save to but i d like to be able to allow my users to decide themselves which directory they want to save the files to and to have the ability to choose which directory to save to
[Code]...
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Nov 1, 2008
this is driving me insane. I have 4 text files that are needed for my application to run and I'm using the following code to read the data in them :
[Code]...
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Oct 30, 2009
I'm just messing around coding a ID Checker that checks registry value. if it does not equal to the string, then the program will close as so:
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim check As String
check = "XXXXXXXXXXXXXXXXXX"[code]....
Now what im trying to do is, where the 'check' is, i want to add more than one UniqueID so that other users can use the app. Lets say a user with a UniqueID of YYYYYYYYYYYYY purchased my app and recieves updates.
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Jan 21, 2009
Error is coming Registry Access is not allowed.While Opening a Key.
Code:
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
NewDelete("HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRun", "Sonia")
End Sub
[CODE]...
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Jan 31, 2009
I've had a bit of a look around the net and on the forums but I've yet to find an answer to my question. I've got Visual Basic 2008 Express and I'm trying to write some registry entries, I can write strings fine just using
[Code]...
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