I am fairly new to vb.net but was programming a long ime with vb6 I have a binary file that is a mixture of numbers (integers and doubles) and strings, such as "Programming with VB". I read the numbers using the BinaryStreamReader.ReadInt32 and BinaryStreamReader.ReadDouble, which are no problem
View 5 RepliesI'm trying to read back a string that I wrote into a binary file, but it's giving me problems and I don't know what's going on. I open and read my file using the code below:
ifstream input([filePath UTF8String], ios::in | ios::binary);
int numStringBytes;
input.read((char*)&numStringBytes, 4);
[Code]....
I'm trying to read back a string that I wrote into a binary file, but it's giving me problems and I don't know what's going on. I open and read my file using the code below:
ifstream input([filePath UTF8String], ios::in | ios::binary);
int numStringBytes;
input.read((char*)&numStringBytes, 4);
[code]....
There is a lot more to the file reading code, but it's proprietary and this is the part that keeps crashing. It runs fine loading the first two files, but when I try to open a third file, it crashes with EXC_BAD_ACCESS at the input.read((char*)names, numStringBytes); line. I don't see any reason that this should crash. I'm writing the binary files in VB.NET using the below code:
Dim myFS As New FileStream(savePath, FileMode.Create)
Dim encoding As New System.Text.UTF8Encoding()
Dim stringBytes() As Byte = encoding.GetBytes("++string")
[code]....
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 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?
few weeks ago i heard my teacher say that it is possible to view any file as a binary array (1s and 0s). if this is possible to do in visual basic please let me know how. Also how would i go about writing an array of binary to a file? For example 01100001 in a .txt file would produce "a"
View 4 RepliesI am doing some exercises on encrypting data. One of them are binary files. I am currently using triple DES to encrypt and decrypt the files both in VB.NET and C#... Now the thing is, once it is decrypted in VB.NET and saved, I can execute it again... But for some reason, my C# file is bigger! 20,4K where VB.NET one is 19,0. The C# file also is rendered unexecutable...Upon a closer look. The files appear almost exactly the same, but C# seems to add in a few extra bytes here and there in (seemingly) random places... I am currently using:
File.ReadAllText(String filepath, Encoding encoding); with UTF-8 encoding.
Here is my code for reading a Binary file:
Dim fs As New FileStream(filepath, FileMode.Open)
Dim str As String = ""
For d As Integer = 0 To l - 1
Dim byt As String = Hex(fs.ReadByte()).ToUpper
fs.Position = d
str+= byt
Next
str becomes:
20202CB962AC5975B964B7152D234B
But when I open the file in a HEX editor, it's:
202CB962AC59075B964B07152D234B70
Why are the 2 different?
I'm new to VB and trying to figure out how I can replace a bit of descriptive text in a binary file. I presume its binary as I cant open it with anything but a hex editor. I've changed the text (file description) in the hex editor and saved it fine but I'm unsure how I go about saving just the section of information I need. I can work out the saving bit later.In the attached file you'll see the highlighted bit I want to edit. I need to replace the whole line or the file corrupt but I can fill it up with null characters and the numbers are just
View 3 RepliesReading binary file from hard drive in VB and writing to database.
View 3 RepliesI am attempting to read a series of double prcision float values (x,y,z coordinates) from a binary file using the binary reader. Everything works fine except that when I read the number back it is different then the number that was written there (original file is generated by mining application).
written number : 78897.6476586
file contents hex : 40 F3 43 1A 5C CF 43 A4 this converts back to the same number as written using a IEE 754 conversion program. VB returned value : -5.45100266729248E-134 using .readDouble()
I have tried to step thru the file in one byte steps to make sure that I have the proper start position but that did not help any.
I must search a binary string for a pattern. This worked fine in VB6 using Get to read a file into a string and using InStr to search for the pattern. The conversion from VB6 to VB.NET changed Get to FileGet and warned of new behavior, but I don't see anything in the FileGet documentation about not being able to read 0 value bytes.
I don't mind at all changing to a new method, but ultimately I must get the data into a string rather than an array.
[Code]...
All I am doing is reading each txt file I find in a directory and finding certain strings in the text then counting how many I find in each file and then once each file has its separate counts it send it to a sql database. I have most of it done, but I cant seem to get the count to separate each file so my problem now is that it counts the first file but when it counts the next file it adds to the first file and so on through all the files
Imports System
Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Data
Imports System.Drawing
[Code] .....
I have a binary converter I am attempting to build and want to read and convert the InputTextBox(alphabetical characters) letter by letter however all I have so far is one letter at a time
Image here is the code I have so far:
Code:
Public Class ConverterForm
Private Sub OpenToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles OpenToolStripMenuItem.Click
[Code]....
I want to scrape string data from some binary text files that contain embedded SQL tatements. I don't need any fancy cleanup--just some way to extract the readable text
View 4 RepliesI need to convert PDF files to Binary strings, the resulting string looks like this"JVBERi0xLjQNJeLjz9MNCjI1IDAgb2JqDTw8L0xpbm...."
I have a program that pulls all the PDF files in a directory, and reads using Binary Reader, but I am not getting the results I need.[code]...
i am trying to read data from a sql 2000 database.one of the fields is defined as datatype:image, Length:16.when I am in SQL management studio and do a select for this one column.[code]when i do a datalength on this field it come up with 2404/My question is, I know this is a numeric field, how do i read this into a vb app and how do I break this down into individual values?
View 2 Replieshow to read a string in pieces.
Let's say the string is 800 characters long. I want to read 100 of them each time. How do I accomplish this?
Am writing code using VB.net 2005 and am attempting to launch a 3rd party console application and capture stdout and stderr strings. Am able to do this but I find that if I want to capture both stdout and stderr strings I have to wait for the process to terminate before I can retrieve any output data. If I remove the stderr read I can capture the stdout data as its being emitted. Thus it appears that the stderr read "blocks" reading of stdout.[code]Does anyone have any suggestions on how to "un block" the reading of the stderr strings?
View 4 Repliesim trying to read "calculator" from calc.exe, now i found the mem adress where the value resides but i have a few problems
1) how many bytes should i read? im not just talking about calculator string but potentially any length string, i get different results with 4/8 bytes but same from 8 - 32 bytes
2) when i read i get a long value 27866486557179971 but how to convert that into a string
EDIT: ok by staring at the return value long enough i discovered that when i convert it to hex it spells "calc" backwards, same for all other strings, i could build a working converter based on that knowledge but now what bugs me is where is "ulator" or the rest of the string, the most i can get is always 4 letters
EDIT2: oh nm that, by moving memory adress a step further i get the next letter along with 3 previous ones and still backwards but i can work with that
ok so now next step would be making a search function for which i need to find out the range of memory to scan, anybody know how to do that?
what is the easiest way to step through a string in this manner... I want to have my program look for one keyword and then another.. in otherwords it needs to find "hello56" and THEN find the word "bob" there are so many places the word "bob" is but I need to locate the "bob" thats after "hello56" Hope this example is clear.
[Code]...
I can retreive all items in my notepad but when I am adding them up in my listbox, and trying to print them in the console. I can only display two strings. I don't know why. My string is a combination of a name, space & score. ex: "luke 300". That is the pattern of all strings per line in my text file. I am separating the name and the score using space as the indicator. When ever a space is found, string before and after the space is retrieved and added to the listbox
Here is my
scorelist = New ArrayList
reader1 = My.Computer.FileSystem.OpenTextFileReader(My.Application.Info.DirectoryPath & "scores.txt")
[Code].....
Any example code for reading and writing strings to and from a ControlLogix Processor?
View 6 RepliesI'm trying to read the XML I generated. Here's my writing code:
'XML EXPORTATION BEGIN
'Create the file
Dim myXmlTextWriter As XmlTextWriter = New XmlTextWriter("C:Simple TimerProfiles" + timer_name + ".xml", System.Text.Encoding.UTF8)
'Choose Formatting
myXmlTextWriter.Formatting = System.Xml.Formatting.Indented
[Code] .....
Say I have a List(Of Tag) with Tag being an object. One member of Tag, Tag.Description, is a string, and I want to make a comma-separated concatenation of the Description members.Is there an easier way to do this than to read the Description members into a List(Of String) and then use the Join function?
View 2 Repliesi 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.
View 3 RepliesI have this code, to read image (saved as varbinary(max) in database):
Private Sub ReadImage()
Dim connection As New SqlConnection(strConnectionString)
Dim command As New SqlCommand("SELECT [Image] FROM z1 WHERE x=1 AND y=1", connection)
[code]....
But it isn't very convenient code. It reads bytes from table, save them to file, and finally open file as image.How can I read it directly to image, without saving as file?
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.
how I could check if a certain file is in text or binary format?I'm using VB.Net 2008 Express.
View 2 RepliesProgram to convert binary pdf file to tiff file in VB.NET..?? We can use third party tools also..???
View 1 Replies