Update An Existing Binary File With New Information?
Jun 8, 2012
i have to update an existing binary file with new information.
binary file contains records from 1 to 5 each record contains different values one integer and five strings.
no i have to update the 1 record with the new information .how do i do that.
i am using filestream,binary reader and binary writer.
Pwd_FS = New FileStream("test.bin", FileMode.Open, FileAccess.Read)
after reading the contents of the record i will assign new values to the recorod writing back should i use
Pwd_FS = New FileStream("test.bin", FileMode.Append, FileAccess.Write) if i use append i am not able to seek to the starting point.
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Jun 7, 2012
i have a requirement where in i have to update the information of a record with new values.how to open the binary file and update with the new information.The existing binary file contains 5 records with serial nos.now i want to update the information of sno 1.i am using filestream, binary reader ,binarywriter SureshThere is an Island of Opportunity In the Middle of Every Difficulty
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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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Jan 18, 2010
I am writing a windows desktop application in visual basic and I need it to connect to a SQL database, take a rows unique id, and using that number generate a file from the binary data that is stored in the SQL database and save it to a file directory. The part that is hanging me up is the creating the file from the binary SQL data.
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Nov 24, 2010
I have a csv file that needs to be automatically updated on a daily basis. I am writing a vb.net app to accomplish this. However, Im having issues with the entire process.I need to be able to read in a csv file, manipulate the data and then update the existing file. I have dabbled with using the Excel objects but I need some assistance.
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May 8, 2012
I have code which saves DGV contents including check box columns as a comma separated text file. I also have correct code which will take the text file and re-insert it into the DGV at a later time. This all works.When I'm working on the DGV, I have this
Private Sub DataGridView1_CellValueChanged(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DataGridView1.CellValueChanged
If DataGridView1.Columns(e.ColumnIndex).Name = "Column12" Then[code]....
So that when the check box is true, columns 1 and 3 turn different colours, and when false, go to a yellow colour.However, when I "re-insert" my DGV info from my text file, the check boxes come back correctly - as true and false on the right rows - but columns 1 and 3 don't change colour. I've tried a "DataGridView1.Refresh" option but not getting it to work.The DGV is unbound. I need it to recognise which check boxes are true and update automatically when the information is opened from a text file.
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Aug 5, 2011
I have a workbook (Workbook1) that runs through some steps using visual basic, which ends up opening another workbook Workbook2). Once Workbook 2 is opened, I need to copy a section of data from it, into Workbook1 int a specific worksheet. I was able to do this by recording a macro, but the challange is, the name of Workbook 1, and Workbook 2, will vary by User. When I created the macro it uses the files as they are currently named. The section of code is below.
[Code]...
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May 11, 2009
I know how to insert a new row into a table that has a binary column. But is there any way to update the binary column once that row has been added? So far an exhaustive google search has turned up nothing. Get the current row that I wish to update delete the row that I wish to update Create a new row with the information from the row I wish to update plus the new binary It just doesnt seem very elegant, and I was hoping I could do the same thing with an update statement. Here is the updated code I am using now for reference
[Code]...
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Nov 2, 2011
Okay have developed a form in vb.net cf using sqlce. I know this is the vb.net section but I feel it's a data issue. I have a table called STORES which has a primary key of two columns (ST_STORECODE & ST_CY_CODE).I populate a dataset with all the store data and to the following to find the required row:-
[Code]...
When I step over the update command I get a concurrency error. Can someone PLEASE help me with this. I have spend days trying to fix it. All I want to do is find a row, do some changes and save it back to the database.
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Aug 17, 2009
I have a DataGridView bound to a non-SQL Server database. I need to allow users to edit existing records but under certain circumstances I need to intercept the edit and instead of committing and updating the dataset I need to delete the edited record and re-add it as a new record. I have tried using every event I can think of to do this but haven't managed to get it right.
The closest I have got is with this:
Dim theRow As DataGridViewRow
Private loading As Boolean = True
Private rowLeft As Boolean = False
Private WithEvents cm As CurrencyManager
Dim copiedRow0 As String
[Code] .....
This almost works but sometimes completely messes up and re-adds rows twice and all kinds of other bad side effects. It seems a really simple thing to want to do but I just can't get it working.
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Sep 28, 2009
how to update records on an existing access database using vb.net with just a textbox and a command button and how a specific record of a field can show up in a label or a textbox
i connected vb.net to my access database by just clicking on "add new data source">>"new connection">>"microsoft access database file" and just continue..tested connection and done.
you can see in the screenshot of my form, by default the left side textboxes are disabled but they're enabled if the user checks the checkboxes and disabled again if unchecked.
assuming that the textbox is already enabled and i want to enter a value in the Brewed Coffee area of the form...for example 5. when i click on my Submit button the value of that particular record in the database will be updated, so in my table the value of the quantity field in Brewed Coffee will be 5.
another thing is that how can i see a particular value on a label or textbox from my database like on the Prices area. in my database if a product's price is 80 then it should show a 80 in the label. the values of the prices from the screesnshot of the form are not the ones on the database xD i just typed them in.
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Jul 6, 2009
im having a problem with replacing some files in a folder, i have made a Auto Upater for a application im making (so beta testers can test it and also get updated stuff to test) now i can replace the Main application.exe with
If File.Exists(Application.StartupPath + "\test.exe") Then
File.Replace(Application.StartupPath + "\update\test.exe", Application.StartupPath + "\test.exe", Application.StartupPath + "\test.exe.old")
End If
This is after i have unziped the main update.zip folder it downloaded
but i also have a Data folder in the Main application folder and inside the new update\Data folder its has updated files now i cant list all files to replace like above as i want be replacing all files all the time, so im looking for something like you have on windows (would you like to replace files) without the prompt its just replaces them, so really im looking for a move and replace without prompting
i have tryed
Directory.Move(Application.StartupPath + "\update\Data", Application.StartupPath + "\Data")
and
Directory.Move(Application.StartupPath + "\update\Data\", Application.StartupPath + "\Data\")
but it errors saying the folder exists and i cant delete the folder as it will have files in that DONT need updating
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May 21, 2011
I have a listview which contains information. This information is retrived from database, 'till now ok. The problem is: I must update the existing items on listview and insert the new ones.
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Mar 16, 2009
I have recently released a free application for some game and now I have added a few features 'the public' requested.
I used Inno Setup to create the installer, which works just fine.
Now however, instead of having the ask the user to uninstall the current version, and then reinstall my new version, I want to be able to give the user an Update install exe which they can simply run and it will update the existing application.
One thing I would like is that the users Settings are not changed. So hence the following questions: 1. Where are the Settings stored? I thought it was in the user's Local Settings <Application Name> directory, but I cannot find my application there... I cannot find it in the All Users or Administrator 'accounts' directories either...
2. Are the Settings stored depending on the Version of your application? (Assembly Version / File Version)?
If 2. is true, then obviously changing the Application Version (which is logical in an Updated executable, no?) would also change the Settings back to default..? Can I avoid that?
Finally, is it enough to simply overwrite the executable? What registry 'work' do I need to do, or can Inno Setup do that for me? I am only using one other file which is the SharpZipLib DLL file.
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Jan 1, 2011
What I am trying to do is update existing records in a dataset with an unbound datagridview. It updates just fine but I have added a simple backcolor change for errors. What I don't understand is it will update fine but throw the backcolor = red at the same time. Am I overlooking something here?
vb.net
For Each dr As DataRow In Form1.DbDataSet.Tables("tblInventory").Select() For Each row As DataGridViewRow In DataGridView1.Rows If row.Cells("colInventoryID").Value = vbEmpty Then 'Do Nothing Else If dr.Item("Inventory ID").ToString() = row.Cells("colInventoryID").Value.ToString() And
[code]....
I'm trying to get this working in a test application before adding it to my main project, so that's why the names of controls are the way they are.The errors I'm trying to show are if "Inventory ID", "Cart" and "Shelf" do not match. When they don't match it doesn't update, which is what it is supposed to do. However, if they do match they update just fine but also show the Inventory ID error. If I comment out that ElseIf for the Inventory, it throws the Cart error. It's like the ElseIf blocks get called even if the If statement is true...
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Feb 22, 2010
any1 has any ideas on how to code a patch maker, (binary differential update) so when i run my patch maker, it output a program (*.exe) that will update files on another machine or local machine, assuming that old files to be updated to a new file having the same data in result;
and also the output patcher should be smaller in size (compressed)currently wad i could think of is a very very simple one but totally useless and not efficient and result large file size patch
1. where mine is read both file data
2. is both byte the same ?
3. [if not same ----> write down the marker value in outputfile1 and byte value in outputfile2]
3. [if same ----> do nothing]
4. read byte if available
5. (marker + 1)
the marker value is how many byte have been advanced so with resulting patcher will read those marker values to advance to the file address (which is the position number) and update accordingly to its byte value outputfile1 is marker values, outputfile2 is byte values corresponding to outputfile1 marker value to advance to the byte position
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Sep 11, 2009
Please can you translate the above line of C# into VB.NET?At runtime, I'm trying to update an existing GridView column, as opposed to adding new columns, just before a DataBind()
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Jan 11, 2011
i need to read binary file and in this file found the string and replace it with other one and save the file afterwords. I found many example to read binary, but to find and replace is for me mistery.
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Mar 11, 2010
I am creating a update member page. I would like the page to auto retrieve the information he or she originally used while registering on my site and display them into the individual textboxes of the update profile page, this is to prevent the hassle to rekey in every individual details and allow the user to edit what he or she wants before it is updated into the database. The problem that I encountered was not able to update the changes in the database. When key in the latest data in address text box and hit submit button, the old data in address text box remains and did not update the database
Imports System.Data
Imports System.Data.SqlClient
Imports System.Web.Configuration
[CODE]....................
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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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Nov 26, 2009
I have a dataset with a number of data columns, due to sizing issues I've updated a number of the varchar columns from say VARCHAR(20) to VARCHAR(50).I'd like the DataTable to automatically grab the new column information, is this possible? I'd rather not go through each column in the table and update the length.
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Nov 1, 2010
My listview clears and updates every 2seconds. Is there an easy to refresh the list information without clearing first? Like taskmanager
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Jul 6, 2009
I have built a very simple application which has buttons, and dropdowns containing links to intranet/internet sites.As I have no Idea on how to put them into a database for easy maintenance, this app will no doubt cause me pain.Nevertheless.. When I do create a new revised version of the file.. eg 1.0.0.1 how to I go about setting the application to auto check for updates ?
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Sep 26, 2011
I have a collection of objects (classes I created), and each one ties to a record in a database. I want an easy way to update the information, so I thought about declaring a record in the class, that would tie to the record on the database. However, I'm having a problem updating it now.
1) Can I declare a global variable for the data context, and leave it open the entire time the program is running? This would solve my problem, but I don't know if I can do that.
2) If not, besides coming up with a complicated class to do this, is there an easier way? Here is an example of what I am trying to do:
VB.NET
Public C as Record
Public Sub GetValue()
Dim SQL As New DBDataContext
Dim X = From T in SQL.Records Select T
[Code] .....
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Jun 14, 2009
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.
Here's the kicker. 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. [code] 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.
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Mar 13, 2010
how I could check if a certain file is in text or binary format?I'm using VB.Net 2008 Express.
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Feb 2, 2010
Program to convert binary pdf file to tiff file in VB.NET..?? We can use third party tools also..???
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Dec 30, 2009
I'm looking for a code snippet that will add graphics (lines, circles, etc.) to an existing pdf file & write it out as a new file.
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Jan 24, 2012
here i am reading files from one root folder and after reading that we are moving that particular file Success folder and taking a copy of that in to back up folder normal
while reading file i will check file naming convention by targeting backup folder if suppose it was exists in backup folder then i m moving the file to duplicate folder
my problem if suppose again same file came to process this file already existed in duplicate folder how do send the file in to duplicate folder, unfornately i dint have any property as file rename
If File.Exists(Swift_Backup + "" + Path.GetFileName(CBFile)) Then
' File.Move(CBFile, Swift_Duplicate + "\" + Path.GetFileName(CBFile)) 'DUPLICATE FOLDER'
[Code]....
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Oct 23, 2011
however, I am stuck at BinaryReader.actually this is what i am trying to acheive through VB.NET.say for the following file type :
JPG file = FF D8 FF E0
BMP file = 42 4D BE 4E
PNG file = 89 50 4E 47
GIF file = 47 49 46 38
the above are the 4-byte headers in Hex(raw) I need to read these headers of any given file using OpenFileDialog using Button1_click event,on selection of any given file(*.* filters ON)it should use the BinaryReader and look for only 4-bytes starting from offset 0, and it should not go to EOF marker (-1).and have a variable to hold this 4-byte header value, to run this in a database table which will check the same header value in the table and would display the corresponding extension of the file. from the table.
I can do this using case, if then...etc.however, I have to do it using Database and also i need to check for testing purpose to use MsgBox() to display this variable which is holding the 4-byte header.however, the MsgBox doesnt allow anything other than String.
PS: I tried studying the methods like:
FileOpen/Seek/Peek/ReadBytes().
but still not sure how to get them work.
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