VS 2008 - Writing Structure To File?
May 6, 2009
Okay, I have a structure that contains numerous elements... mostly strings, one or two integers. I maintain an internal array of that structure. The structure contains ONLY data elements, no code.I want to save the data to a file. I know that I CAN use StreamWriter.Writeline()to put out a formatted string for each element in the array. But is there any way to simply open a binary output file and save each structure, one after the other? And conversely, to load the array again in similar fashion? Something similar to this in intent, though I realize the code below doesn't work.
[code]...
To repeat, I want to write an entire structure to a datafile quickly and easily, without having to save each member of each element in the array. And conversely, to read the data back in the same way for easy loading of the array.
View 1 Replies
ADVERTISEMENT
Apr 12, 2010
I have several quesions about reading/writing structures from/to files.In a scenario when I open a data file having its own header and variable data fields I create a structure that represents a header consisting of 9 bytes:
Public Structure HeaderInfo
Public DataField1 As Integer
Public DataField2 As Byte
Public DateField3 As Integer
End Structure
I'm using this code for the time being:
vb.net
Public Function ReadHeader(ByVal FileName As String) As HeaderInfo Dim ReturnInfo As HeaderInfo Try Using br As New IO.BinaryReader(New IO.FileStream(FileName, IO.FileMode.Open, IO.FileAccess.Read, IO.FileShare.Read)) With ReturnInfo
[code]....
The first question is - can I fill the structure directly somehow? Some structures are very long and filling them this way will be tedious. For example, if I know the length of the structure I could read the needed number of bytes in a byte array and somehow marshal these bytes into the structure.I can use Marshal.PtrToStructure, but then I would need to get an IntPtr of my byte array. I use <Serializable()> attribute for my structure.
View 10 Replies
Apr 21, 2009
Im trying to load a price of an item from a prices file (Items). The variable (ItemName) is taken from a listox populated from the file on another form. And (Item) is the structure which i saved the prices information for into (Items).
What im trying to do is take the string from the listbox and change the textbox (txtCurrentPrice) text into the price for the highlighted item, which is also the name of the (txtItem) textbox.
However i cant find a way to reference the Item.(ItemName) to get the correct price from within the file, as ItemName isnt a member of the Items structure Item instance.
ChangeItemForm
Private Sub ChangeItemForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
[Code]....
ItemName holds the name of one of the variables saved in the structure. So say if ItemName was holding "IridescentRoll" As its string I would be trying to find Item.IridescentRoll, which would show me the price of IridescentRoll which im trying to put into the textbox. and As Item.IridescentRoll = 3.35 it would display 3.35 in the textbox.
As you have probably guessed, the Item.ItemName doesnt work ('ItemName is not a member of...'
Is there any way to write this without having to create a new record for each item? As that would take a while, and im not sure i have the time x.X
View 5 Replies
Apr 25, 2010
I'm having a problem that's driving me crazy; I can't understand how to convert the XML structure into a class structure (that I want to use to hydrate a XML document).
The XML document looks like this:
xml
<?xml version="1.0" encoding="utf-8"?>
<artists xmlns:opensearch="http://a9.com/-/spec/opensearch/1.1/" xmlns="http://www.spotify.com/ns/music/1">
[code]....
View 2 Replies
Jun 24, 2010
How to display a hierarchical file structure with checkboxes for each file and directory. The end result should be something like:
+[] ROOT+[] dir1[]file 1[]file 2+[] dir2[]file 3[]file 4
How I might do something like this? The intention is to take in a full list of files and be able to pair it down to a custom list.
View 4 Replies
May 10, 2010
i have the code bellow to write a structure to a text file, but nothing is happening,how can i get a error message if the file doen't exist?
Imports System.IO
Imports System.Runtime.Serialization.Formatters.Binary
Public Class Form1
[code]....
View 1 Replies
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.
View 4 Replies
Feb 13, 2010
I found the following links to fill a listview and then write it to a CSV.[URL]..And I modified the codes and created the project which is attached to this post.
The project works OK but my only problem is that when it creates the CSV file, columns are not created in excel. For example if I expect the data to be placed in A1, B1 and C1 cells, the data will all be placed in A1.
View 25 Replies
Jul 6, 2010
I have a structure in memory which is working fine - now I need to write this entire structure to a file. The below code almost compiles, the problem is that "mstaRecordInfo" cannot be changed to a string, probably because of the Date field. I've just spent over an hour experimenting and searching the web but have gotten no closer to a solution.
[Code]...
View 7 Replies
Jan 16, 2010
For writing to a Text file and saving it somewhere like my C: drive, Should the following work?
Dim 1 As NewStreamWriter ("C: est.txt")
I want to put this code into the On btn click section so it outputs the content of my listbox into a .txt file ready for printing if needed
View 20 Replies
Jul 26, 2009
im trying to write a .reg file out that is written into the exe's my.resources dynamically at compile time from a diffrent app... but the .reg file gets messed up and alot of extra txt gets added ...
[Code].....
View 8 Replies
Jan 6, 2009
writing a text file, If LineData(1) = "ABCDE" then I need the file to look like this when the text file is opened:$mov "ABCD" D10 No other quotes or spaces are allowed. Now I have opening and closing quotes on the entire line no quotes on the ABCD section
DRegister = 10
FileName = "C:PLC Print2.txt"
FileOpen(ff, FileName, OpenMode.Output)
For K = 1 To I
[code]....
View 7 Replies
Jul 11, 2009
Well I'm in the middle of making a program to edit .ini files. Although I have hit a snag. I can save my settings (relies off checkboxes) with ease, however if I change something and/or hit the save button again even after the code has finished, both my entire .ini files are cleared (filePath and filePathPrefs) and all text is gone. Here's my
[Code]...
why it's clearing the .ini file even after the initial write worked? I've tested to make sure the entire code has finished before making another save with different settings but the issue happens again.
View 5 Replies
May 20, 2009
i read a text file and i need to overwrite the first line of the text file this is my code
Private Sub readProvisionOrder()
'Loads ProvisionOrder from text file
Dim sFileName As String ' name of file in the directory
Dim sr_ProductsFile As StreamReader 'file reading variable
[code]....
View 4 Replies
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]....
View 21 Replies
Oct 30, 2009
So what's happening is, I open the original image, get the graphics object, draw a string to it then save it as a new file.
vb
Dim path As String = ImageThumbs.Rows(0).Cells(ImageThumbs.Rows(0).Cells.IndexOf(ImageThumbs.SelectedCells(0))).T
[code].....
View 3 Replies
Jul 24, 2009
Well I basically know how to read a text file, replace text then write to one. how to append text after a specified string (ie, insert text at a specified line, removing the text after a string in a line and changing it without altering other lines, etc). Can someone please tell me how I would go about adding a string after a certain string in a text file? For example:
I Have:
test
example
hello
[Code]....
View 4 Replies
Jan 3, 2010
I'm reading a txt file into an array and then writing a new file one line at a time. The reason i'm using array is that i'm searching for a few lines that i want to find and replace.
However in my file I have some ascii characters but they aren't read well. I read something about System.Text.Encoding.Default but I don't know how to implement it in my code.
[code]...
View 2 Replies
Feb 24, 2010
My code is crap, so I don't really think it will be useful because I've been going about it differently than I really want to:[code].....
I really don't wanna be loading a file in, I just wanna use XMLDocument() to create a file from my DataTable.But, my file ain't coming out right and I'm sorta just lost as to how this is all supposed to fit together.
View 8 Replies
Jan 5, 2012
Module Module1
Public Structure structure1
Public TRANS() As structure2
End Structure
Public Structure structure2
Public X() As Integer
End Structure
End Module
View 17 Replies
Feb 13, 2009
I am developing some program which will frequently read a file and occasionally write to the file. The file, however, is extremely huge - it may contain hundred of thousands of rows, and each row has a particular meaning to the program. That, is there may be loads and loads of rows, and a row may contain additional elements.For instance, a row might look like the following:
Code:
3 00000111000000 01110110 2 0
I am writing my program in C#, just fyi.Given my very large file, I am refraining from the idea of just using a text file, which is an obvious choice. I am also hesitating to use a database and a table.
View 1 Replies
Jan 5, 2010
I'm new to VB 2008 after having spent a long time with VB6, so I apologize if this is a stupid question. But I'd really like to have this straightened out.
Let's say I have a pretty large structure that has lots of properties.
Code:
Now say that I want an internal database with about 10 instances of this structure total, describing, say, 10 different products that a store sells. When these values are loaded from a database, they remain totally static. (However, they can be different each time a program loads)
Now say that I have a class. Each instance of this class is a type of that BaseProduct structure. Meaning, each instance of the class pertains to one of the 10 types of products that the store sells. However, this class has additional properties that pertain specifically to each instance, which are not static.
Code:
Now, the problem here is... If I have 200 different transactions, each one contains an instance of BaseProduct. BaseProduct is HUGE, and is largely redundant (only 10 types possible), so I think it's a little silly to include a whole copy of it with EVERY transaction. However, the Transaction class really needs information regarding the base product it pertains to. Is there a way to, instead of declaring a New BaseProduct in the Transaction class, to simply make one of the properties of the Transaction class a pointer to a BaseProduct variable?
In VB6, I would accomplish this by making a BaseProduct(10) array, and then giving each Transaction an ID number referring to an entry in that array. But in VB 2008, using class structure, this is impossible. I can't define the BaseProduct(10) array outside of a class in a namespace, and if I define it in the actual application's form, then the class loses modularity since it relies on the application that's using it.
View 11 Replies
Aug 29, 2009
I am trying to communicate with an external device and i am trying to send a byte array to the external device via sockets but i am always getting a response the message size is too small so i am not sure what i have done wrong. Between the data type there should be no alignment present and all numbers are represented in little endian format. The char array is not null terminated as mentioned in the protocol specifications.
I have to send data based on a struct that embeds 2 other struct. So here's my vb.net code for the struct used to convert to byte array and the sending part.
Public Structure MESSAGETYPE_OIP_Login
Dim Header() As COMMANDHEADER
Dim UserName() As PSTRING
[Code]....
View 2 Replies
Jul 5, 2009
So I need to write out an object to a text file as well as read in objects from text files.How do I accomplish this? This is the code i've used to read and write just simple lines of text. Is there a small modification to this or just a different function i use to read in an entire object?
Code:
Dim path As String
path = "Security.txt"
[code].....
View 4 Replies
Jul 17, 2010
I have just recently been using VB 2010 after using VB5. I have noticed a lot of changes. The problem I have is that I wish to open and save text files to and from arrays in the background. I've attached what I would do in VB5. I have searched around, but all the examples I find use a Textbox instead of an array. Can anyone show me how I can do this with VB 2010?
View 1 Replies
Jun 9, 2011
I am creating a text file using a save file dialog and copying the path to the text box which file is used to write from vb.net. when i try to write i get an error "The process cannot access the file '....fileName.txt' because it is being used by other program".
The code is below
Public Sub writeInTextFile()
Try
Dim oWrite As New StreamWriter(TxtOutputPath.Text)
[Code].....
View 4 Replies
Mar 11, 2010
I am attempting to gather a group of file names from a directory. I am able to do this. I tested the code by having the list populate into a listbox and all desired items were added to the list.
Here is my code:
Dim di As New IO.DirectoryInfo(strPath)
Dim dir1 As IO.FileInfo() = di.GetFiles("*.txt")
Dim dFiles As IO.FileInfo
ListBox.Items.Add(dFiles)
However, a listbox is not my desired output. I am attempting to write these file names to a text file for purposes of then parsing the information to a datatable to compare with another datatable. How to get my filenames written to a textfile.
View 2 Replies
Aug 17, 2010
is there any way to convert a structure to a XML file? I searched in this forum and in Internet but only found conversions from classes to XML files. I also found a working conversion (or better serialization) from structure to binary file but this is not what I want. My structure looks like this:
Public Structure MyStruct
Dim bFraming As Boolean
Dim CtrlBus As Integer
[Code].....
View 7 Replies
Dec 17, 2009
I am trying to write a pre defined strcture into a binary file. how do i achieve this ?
my typical strcuture looks like
userid 2 bytes
company name 2 bytes
email address 40 bytes.
View 2 Replies
Sep 30, 2011
I have the following .dll file created and added as a reference in my calling project; however, being new to vb .net I seem to be having difficulty calling the dll that I created.I want to pass a string to the below function, break that string out into two strings and then return the structure.
Namespace Item_Breakout
Public Class Item_Run_Breakout
Public Structure vbItem_Code[code].....
View 8 Replies
