Writing Length-prefixed Strings In VB6 For BinaryReader?
Jun 27, 2010
I want to create a binary file in vb6 which contains variable length strings and which will be read in VB.NET by using BinaryReader. Since BinaryReader requires the variable length strings should be length-prefixed, I have to write them accordingly.
The obvious first thought is: Public Function CheckStrings(ByVal input As String()) As Boolean For Each s As String In input If s.Length > 0 Then Return True Next Return False End Function I'm sure there is a simpler way than that though. At least simpler in terms of the code if not necessarily the performance.
Here's my final code: <Extension()> _ Public Function AnyNonZero(ByVal value As String()) As Boolean If Not value.All(Function(x) String.IsNullOrEmpty(x)) Then Return True Return False End Function
I'm generating a list of names from my database, but I need to validate them so they are no longer than 15 characters.
Dim Name As String Dim txtFirst = "../../Names/first.txt" Dim txtLast = "../../Names/last.txt"
[Code]....
I need Name to be no longer than 15 characters, and it doesnt matter if the name stays in tact, it just needs to cut off characters from the end of the string until its 15 or less.
This is related to my last question.Even though Access considers Nulls and zero-length strings (ZLS) separate values, often developers wish to treat them as equivalent for the sake of an If...Then statement or some other stretch of code. One way to accomplish this is to write code like this:
' Not so efficient If IsNull(varAge) or varAge = "" Then ' do something
What I need to do is find a string that can be any value, and is placed between ">" and "</" with a minimun length of 5 and a maximum length of 7 and contains exactly 2 dots.
So if I have a text file like this:
<a href="www.site.com">a site</a> text<br /> More test<br />
[Code]....
I want it to find only the 5.0.77. And no, the number isn't always between h2 tags, and the number isn't even always the same. The only thing that is static about it is that is is between ">" and "</" and that it is between 5 and 7 characters and contains 2 dots.
I've got my self in to a pickle here.I'm trying to do something I used to do in basic? At-least I think you can do this in Basic, you know Qbasic,What I'm trying to do is put 4-8 strings on to one line separated by a comma.Example might be:
writer.writeline (bob1, bob2, bob3, bob4) Out put might look like Test, Test2, Test3, Test4
I'm tried looking in to formatting of writeline/write, but I didn't get any where with it.
Also if this is possible- I would like to be able to read it just like :
reader.readline (Rbob1, Rbob2, Rbob3, Rbob4) If anyone cold just point me in the right direction, I'm sure I can figure it out - If not... Well I will ask another question.
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);
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")
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?
I have tried to create a method for writing information from an instance of a class to a binary file. The code works fine, the only problem is finding the end of the file. After it has read the last value that should be read, the basestream.Length is still higher than basestream.Position (by a random number)In my case I have created a class with two fields (name and birthday), one that is string and a date field. With my code, this should write 5 lines to the file (classname + nameofNameField + StringValue + nameOfBirthdayField + DateValue) When reading there's still more information in the file, when I have read the DateValue. Why? How do I find if it has read the end of the file?
Imports System.Reflection Imports System.IO Public Module BugHunter
This code generates a bare basic file reader that reads a file and displays its contents in hex format The bytes of the file are displayed 32 bytes at a time in hex and string format.I've found it quite useful
I want to read 15 bytes of data starting at byte 40 and ending at byte 55. I then want the value of the 15 bytes of data to print to textbox5. I know this should be a simple task but I'm having a lot of trouble figuring this out.
Can you delete stuff inside of a file after you have committed it to the binary file? I noticed that you can still read the stuff inside of a binary file.Also is there a step by step tutorial for the binaryreader and writer
Private Function GetImageSize(ByVal FileName As String) As Size Dim ImageSize As Size Using BR As New BinaryReader(New FileStream(FileName, FileMode.Open)) Do
[code]....
I want to display photos of people when the mouse passes over their name. I wanted to be able to size the picture box to be proportional to the various photographs and let the Stretch property handle the rest.I used the code above offered by John Wein to a question from 2009 to read the dimension of the picture It worked fine until I pass over the same person twice. Then I get an error that the file is in use by another process.I tried adding:
"BR.Close"
With and without
"BR.Dispose"
But the file is still locked-out on the second pass. I tried setting "PictureBox.Image = Nothing" when the mouse leaves the square, still the file is seen as in use and locked.
I created a subroutine to copy and paste a file using the binaryreader and binarywriter. It works fine from what I can tell. The file sizes match up any how but I was wondering if anybody had an idea on a better way to get the amount of bytes that should be copied in one set.
binwriter.Write(binread.ReadBytes(100000)) I want to make the readbytes as large as possible without crashing the users computer.
Im trying to create a bittorrent client, now I'm in the bencode decoder reading the .torrent file with the use of a BinaryReader(datos variable), when I'm reading the value of "pieces" of the "info" dictionary, but in some part of the value of "pieces" i can't read the bytes of them, therefore all of the rest bytes of the "pieces" don't be readed.
this is the code I'm using to read the value of "pieces"
Private Function decodeString() As BEncodeString Dim numeric As Char = Convert.ToChar(datos.ReadByte()) Dim value As BEncodeString
Why does this programmer use a binary reader to read bytes, why not the client.getstream.read or streamreader?
Case RequestTags.Connect 'sent from server to client informing client that a successful 'connection negotiation has been made and the connection now exists.
End WhileI am trying to read from the ": " to the end of the line. I keep getting this error: Index and length must refer to a location within the string. Parameter name: length
I am using BinaryReader class to read binary file.But I am facing problem while reading number of bytes from it.I have written code to read only 2 bytes from it,it works well on my machine and read only 2 bytes,but when I deployed that code on server machine it read 4 bytes from file.Whats wrong in the code?Is it due to processor i.e.. 32 bit processor/64 bit processor.
I need to parse a binary stream in .NET to convert a 16 byte unsigned integer. I would like to use the BinaryReader.ReadUIntXX() functions but there isn't a BinaryReader.ReadUInt128() function available. I assume I will have to roll my own function using the ReadByte function and build an array but I don't know if this is the most efficient method?
I have a field displaying on a datagrid that the user has asked to be variable length based on the data that is returned. Is there an easy way to determine how many characters are returned for a field and then converting that to a pixel length so that I can change the length of the field in the code.
If using the following in an if statement I get an error: If trg.Name.Substring(4, 6).ToUpper <> ("ABCDEF") Then I get the error: "Index and length must refer to a location within the string. Parameter name: length"
I assume this is because the string (trg.name) is too small for the 4, 6 substring. What would be the correct method of working around this problem? VB.net Studio 2008.
I am working on a UDP Client/Server, and currently i have them sending back and forth strings, which i convert to bytes, and then open the bytes to read. I want to now send an Object instead of those strings, which includes multiple unsigned integers and strings.
I have a list of strings. For each string in that list, I want to prepend another string. I wrote a method to do it, but I was wondering if there was something already in .NET I could use to do this. It seems like something that could be built in, but I was not able to find anything.
Here is the method I wrote:
Private Function PrependToAllInList(ByRef inputList As List(Of String), ByRef prependString As String) As List(Of String) Dim returnList As List(Of String) = New List(Of String) For Each inputString As String In inputList returnList.Add(String.Format("{0}{1}", prependString, inputString))
[code].....
It works, but I would rather use built in functions whenever possible.