I am writing a program to calculate Pi to several hundred billion decimal places and this will require lots of GB of memory. I wrote a test program in VB2008 that saved the first 16 digits of Pi (without the decimal point) to both a text file and a random access file, just to be sure it was outputting the numbers properly. For reference the first 16 digits of Pi are:
View 8 Replieshow 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.
I am a total noob to VB and am only doing an A-level in computing. i'm using VB 2008 express edition am trying to make a windows form application which picks a random file from a folder and displays its contents in text boxes when a button is clicked.
View 3 RepliesI have managed to learn a little of VB 2008 but I'm still struggling. I managed to convert one VB6 program to VB .net but all the file IO in it is sequential access.I'm trying to convert a VB6 program to .net. This program uses almost entirely random file IO.In one of the books I have, I found an example which, with a minor mod worked. I tried using that code to modify my program and it does not work. In my code, the FileGet results in the obj containing null strings. Yet in the sample program using the same structure, the obj contains actual data.The file is being opened because the record count is calculated correctly [iUpper = LOF(F_Trk) / TrkLen].
I used a Type in VB6 which I converted to a Structure in VB 2008. The function in which the problem occurs is below as well as the Structure declaration and the Function it calls (PAB) which is a derivation of the PathAddBackslash API call.Is there an easier, more efficient way to achieve the same results in VB .NET?[code].....[code]......
I'm doing a Program for a Friend of mine, He Want to have a Console Program Running on his Computer.OK the problem i am having is With Stream Read, I have 3 test users inside Test File, if User 1 logs in his information is store in logged file with time and data.but if User 3 logs on user 1 2 and 3 are all saved on the logged file
i dont have read to end of file in my Code.i dont have my Program with me, so i going off the top of my head i have something like this what i want to be able to find out how to do is Right from any part of the file and out put it, I take it i need to use Random Access but how to i code Random Access for this type of file. All i can find is how to Randomly place Words in a text file with Length and size.
[Code]...
Years ago when coding with VB6 and earlier, I used a file open command to create, read, and write a file that made it easy to store useful information.I believe it was binary and you wrote/read the data to a specific line in the file. When you opened the file with something like notepad, it just showed random ascii chars. When I needed a line of data, I could specify what line to load it from.
View 2 Repliesi have a problem where i've hard coded the file path of an access database i'm using with a VB.net program. this means that if i publish the program the database doesn't publish with it and i have to "ship" the program with the the database file separately and create another form so the user can say where the file is held. i don't want to do this.is there any way to get the access database file to publish with the program and then access that file path by code? for example the database file is held in the same folder as the installed program and then is accessed by code so there is no need to use a specific file path.
View 1 RepliesFor my application, I want to have three output files, a small summary output, a medium-sized standard output, and a larger detailed output. It's convenient to write to these from various subroutines in various modules to report data and progress at the thing runs.
[Code]...
So I'm in the final stages of finishing a program I've been working on for nearly a year now, and this is basically my final hurdle. The Save dialogue is working beautifully, with 'flags' in order to switch it over from the regular input into text boxes to the Listbox input protocol.
However, I'm having a *** of a time getting it to take lines from the text file and put them in the proper text box. Here is an example file:
Quote:
SHOWNAME
CALLNAME
BREED
[Code]....
So with the sample file I provided above, in the textbox named callNameText would appear "SHOWNAME", and so on and so forth. With this build, I get a NullReferenceException on the "Me.Controls(strboxNames(i)).Text() = strAllText(ati)" line.
how to proceed. One of our customers is going to be sending me a flat file (ASCII-Text) that I have to break down and scan. Every line ends in a CrLf - So I know I can use StreamReader and ReadLine(). I did get it to work on one of the test files they sent.(A very Short file) However, the file is not delimited at all and every field is padded to the full length they specified. Here's the format of the file:
[Code]....
trying to input a text file that's tab delimited that looks something like this.
2.2 5.6
3.7 9
1.2 9.1
[code].....
I need to implement a routine to read a plain text file, BUT that file has a predefined format.The file format is as follows:
Quote:
<FILE_PROPERTIES> 'The "< >" also appears
Propertie1="String" 'It's possible to have spaces after or before the "="
Propertie2="String"
Propertie3="String"
PropertieN="String"
[code]....
Is there any Windows API Routine to read something like that?Or could you point me an URL where something is implemented?I don't want a procedure to read the file line by line and comparing them with Line Input because blank spaces, empty lines and comments starting with " // " may appear too, and I don't want to take them into account, but also I need to save changes to the file, but only to the modified section, without having to read the whole file, and re-write it completely.
Binary access can't work, because I don't know what's the size of each "section", since the number of elements into it can change.
I need something like the "ReadINI" Windows API Procedure, but allowing me to read the "[XXX]" sections headers, and also the "<XXX>" file title header.
Before I begin I would like to mention that I am not a noob in VB, it's just I've never had to do anything this complex before. Basically what I want is to have a program that you can load a txt file in, have it copy key words, and paste it in a textbox so I can use it later on. So in this text file, there is a bunch of info, but I am only needing a certain part. Here is an example of a text file (actually a .dat file, but is easily read):
[Code]...
how to save information into a text file from runtime VB2005. However, I wish to be able to write the information into any kind of form of file that cannot be simply opened and read by anyone (such as text file can be). Is there anyway that VB2005 can do this?
View 2 RepliesI'm using the SaveFileDialog to save listbox info into a text file. The files save fine, but when you go to save the file, if you hit the cancel button, it will overwrite the previous file you saved, because it's name was the same and it seems to save the previous file as the new name for your next file. Is there any way to catch if the user clicks cancel, and then exiting the sub if they did?
View 2 RepliesI need to be able to change a path inside a document ( a config file to a program) to the current directory of the application im creating in VB so the text file looks something like
Quote:
something=234
blabla=io
ServerRoot=C:Server
i need to change c:server
When you need to do random access to the lines of a text file, the regular solution is to put those lines in a list and access them in that list.But doing this if the text file is large creates a large memory overhead and may cause some memory stress on the application.This class maps the file and provide the ability to read any particular line in the file at a random position, without the need to read or put in memory any other line but the desired line. The only memory overhead involve is the 1024 bytes buffer of the base stream.Even if the file mapping can be a process that consume a noticable amount of time if the file is very large ( ~ 5 seconds for each 100,000,000 caracteres) , once the mapping is done the access to a particular line becomes instantaneous regardless of the size of the file. (The file mapping can always be done at a convenient time (ex when the process load) and can be done on a worker thread The class is base on a StreamReader to support the differents Text Encodings Example uf usage ( As I say, if the file is very large, dont do it like that, but declare the class at a convenient time)
Imports Reader = System.IO.MyStreams
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
[code]....
how I could check if a certain file is in text or binary format?I'm using VB.Net 2008 Express.
View 2 RepliesI created an application that when a user logs onto their Windows account, a Form is displayed outlining the current Computer Usage policy set by the insitution and gives the user two options either Agree or Dis-Agree. The two options are in the form of buttons, with events that depending on what the user clicked, will create a log text file at a specified location, with enteries of Date,Time,CurrentUser, and if they agreed or disagreed. If they agreed the application after creating/amending the file will then terminate, otherwise it will update the file and then force Windows to logoff the current user.
Now I made a shortcut of the .exe of the application and placed it in the startup for all users, and yes the application loads at startup for all the users following the procedures mentioned above. The problem I am facing is, that if the current user logs off, or is forced to log off, and another user logs onto Windows, goes through the whole ordeal mentioned above, the application is denied access to the logfile that was created under the previous user, and thus crashes.
So my question is, how can I created a text file using vb 2008 application, that is accessible by multiple Windows users. I have even tried changing the location of the created file to the shared folder, but the end result is the same.
I know that Deleting a specific line in a sequential text file is impossible but instead copy the needed lines and not copying the unneeded ones to an output file .. killing the old one and renaming the new one with the same.. I can't make this step...
That is my record file
Code:
Input #1, CustomerName, CustomerHomeAddress, CustomerBussAddress, CustomerTel1, CustomerMob1, CustomerID, DateRent, CarRegPin
Code:
"Josek Sam","68 West Land Street","149 Union of States","4524563","45635463","JOSKSAM1",#2009-03-02#,"MILANCGLZ2008"
"Josef Malm","142 Unions Street","64 Hamersters Street","452504","42542054","JOSFMALM2",#2009-03-06#,"MILANCGLZ2008"
"Dave Green","131 Oxford Street","96 BlueBane Route","452542452","43254345","DAVGRN3",#2009-03-07#,"MILANCGLZ2008"
I made a form that when you put your CustomerID in Text3 Box.. it access the records and make some calculations. now.. The customer will return the car.. Then his data should be deleted.. I want to know how to make that when I enter the CustomerID and press on the Command button .. It copies the other lines to a new output folder and doesn't copy these ... So it appears to be deleted using this way..
I've got an application that passes commands to a terminal window and saves all the output to a text file Here is one of the commands my application passes to the terminal
MyProcess.StandardInput.WriteLine("host " + device)
The output of which is
"HostA has address Y.Y.Y.Y"
this along with a whole bunch of other text is saved to a text file...my question is how do I find the sting "HostA has address Y.Y.Y.Y" in that text file and then extract the IP address and assign it as a string variable?
Ok what i want to do is have a user specify a directory when this for is opened and have it remembered everytime this for is open,Also i have a few buttons and whenever the user clicks on one of the buttonsa i want it to open a txt file delete everything in it and write a value that i specify
View 9 RepliesI am trying to import a TAB (NOt comma) delimited text file into a DataGridView. The following code works fine if I have a comma separated file. All I have to do is change the FMT to "Delimited".It just does not work with FMT=TabDelimited. All columns are read into single datatable column. The text file is ANSI text and I have double checked to make sure Tabs are tabs and not spaces, even exported a sample Tab Delimited file from Excel.Can this even be done using Text Driver? [code]
View 2 RepliesI am making a simple application that will be able to store competition data into a text file that I have given a custom extension to on saving. Here is an example of the format that i have saved the data in.
Code:
[Comp_Name]Test Competition[Comp_Name]
[Location]Silverwood Lurgan[Location]
[Type]Teams[Type]
[Code]....
When i open the file, i want to redisplay the data in separate text boxes. Later on in the project i want to be able to search within the file for headings for example;
if "[Heat1]" is present then get all text between [Heat1] and [Heat1]
i am currently able to use the streamreader and open file dialog to retrieve the entire string of text fromthe however i am not sure how to go about getting the text between the headings I have used.
1 List all of the data from Teams.txt in a Listbox. Include suitable headings.
2 List all of the data from Results.txt in the Listbox (use the same Listbox as in 1 above).Include suitable headings. Note that you cannot assume that the file contains onlyresults for the first 3 weeks of the season. Your program should be able to process a results file with more or fewer results.
3 List all of the data from Results.txt in the Listbox. However, in this case the actual team names should be output (your program will need to get this data from Teams.txt. The data should be formatted so that it is aligned correctly. Include suitable headings.
The output might look as follows:
Home Team Away Team Home Team Goals Away Team Goals
Bunbury Braves Nedlands Nodders 5 2
I am using Visual Studio 2008 on Windows XP SP3. User has Windows 7 Pro (32 bit). The IO code below works for me. The read code works for user, but the write code only works for new files. If the user tries to overwrite a current data file, then no data is written to disk. I have done all the usual IO checking (valid file name, etc.) and have excluded it from my same code. In my app, FileSave and FileSaveAs both call WriteDataFile(FullFileName). Any reasons why FIleSave would work on Windows XP, but not on Windows 7 Pro (32 bit)?
Code:
Public Function ReadDataFile(ByVal FullFileName As String) As Integer
' reads a Data file from disk
'
' Format is a text file, with [TAB] seperators and [CR][LF] as line terminators
[code]...
i have 5 textboxes in a form. I have a streamwriter that writes all of their text to on text file like this:
Code:
Dim xfile As String = Application.StartupPath & "/Set.txt"
If File.Exists(xfile) = True Then
Dim writex As StreamWriter = New StreamWriter(xfile)
[code]....
I was wondering how to get the text under the each number and place it in the corresponding textbox.
i am trying to make a program that downloads a text file from the internet, the program display/edits it and then it saves it, lastly it uploads it. How can i make it that it downloads a text file and displays and then uploads it.
View 5 RepliesI have a variable (double) that is constantly update in real time with data from an analog input. I would like to write this data as it comes in to a txt file. When I stop my acquisition of data from my analog input, I should have a txt file with all that data stored on my computer wherever I want it. The way I'd like that txt file to be laid out is like so:
Test Title: "This info comes from a string variable"
Operator Name: "This info comes from another string variable"
Test Date: "This info comes from yet another string variable"
[code].....
And so forth. As you can see I would also like to write the time for each data. This depends on my Timer interval which the user can set. The default is 50ms. So by default, y1 y2 y3 would be 0, 50, 100. How would I generate such a text file?
PS: I have five variables (X, Y, strTitle, strName, strDate)
i am working on a project to extract all md5 hash from a text file;btw i don't mean the text file hash i talking abt the hash string inside the file?
View 3 Replies