I would like help to compress a file with zlib. I have have searched google for ages and found losts of examples but i can't get any to work in VB 2008 Express. I am also not sure which version of the dll to use as there seems to be a few for VB.Can someone post some code that will work in VB 2008 so i can see how to do it and also a link to the dll that you used.
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My app receives a PDF as a base64, zLib deflated string in an xml file. At least that's the format I'm told it is in. It gets stored in a database, then I need to recreate the PDF from that string. I created a test app to figure it out. The function below takes the string and is supposed to return it in a decoded, inflated format which I believe I'll be able to use to rebuild the original PDF (I'm not there yet). I've done lots of research and found a few different libraries and ways to do this as well as received a java program from the developer who is sending me the PDF to use as an example. However I can not get the string to a usable format. Using the ManagedZLib.dll and the function below seems to get me the closest. As far as I can tell from debugging, everything works until I try to decompress:
zStream.Read(decompressedBytes, 0, decodedBytes.Length - 1)
This produces a "zLib error: -3". The only info I can find on that error is it is a 'data error'. There is very little other information on the web about it.
Public Function DecompressString4(ByVal origString As String) As String
Dim returnString = Nothing
' get the base64 content into String
ManagedZLib.ManagedZLib.Initialize()
[code]....
I would like to decompress/compress text files in zlib format.
Here's what I tried:
- Downloaded zlibwipa.dll from [URL] and tried to add a reference to it but got an error saying it is an invalid assembly.
- Downloaded DotZLib from [URL] but can't get it to work, error message: Unable to load DLL 'zlib.DLL': The specified module could not be found. (Exception from HRESULT: 0x8007007E)
- Looked at this [URL] but couldn't do much with it
This files are textfiles created from flash with ActionScript 3.0, but compressed, using the ByteArray class's compress() method. I know Flash uses zlib algorithm for this, and I would like to open and use this file from vb.net.
I am using something like :
FileOpen(1, OpenMapDialog.FileName, OpenMode.Binary, OpenAccess.ReadWrite)
Dim a() As Byte = {}
FileGet(1, a)
[Code]....
How do I decompress a zlib compressed file with byte arrays?
How do I create 7-Zip archives with .NET?
I'm looking for ways to do compression and decompression in 7z format via code in VB.NET and C#. Is there any library or .Net code for this purpose?
I know there are GZipStream and DeflateStream in .Net but I want 7z format for better compression ratio.
I'm currently working on a utility software, file compression, with VB.Net. And using an open source library to compress and decompress files - DotNetZip - and already running.
My friend told to make it unique and not traditional, that I make the output compressed files cannot be opened with other compression software. Now my question is... is it possible that way? Using an open source library which the output format is ".zip"?
I first thought that changing the file extension of the compressed file to unknown format so it can't be opened when you try to decompress it, unfortunately, using the "Open With..." function of windows it could still be decompressed.
Is it really possible? OR what other features can I add that WinZIP doesnt have yet? I compared my work to WinZip since the same output is ".zip".
i wanted to ask is there any means i can compress a video file(.avi) to a small size than original.Which API should i use(except the DirectX)..?Is DirectX advisable?
View 1 RepliesI'm trying to compress a file in .NET, but having some trouble. The zip file is created, but it's only 1KB and no files are within the zip file. Basically, it's not working for some reason and I'm not sure why.
Public Sub CompressFile(ByVal fileName As String)
Dim strOutput As Stream = File.Create("zippedFile.zip")
Try
Using (strOutput)
Dim strInput As Stream = File.OpenRead(fileName)
Using (strInput)
[Code] .....
I'm wanting to make a program to rip dvd's but more importantly to store them so the user can watch them when they want. To keep the cpu's memory down I figured I can compress the dvds when the person just has them sitting there and then decompress them when the user wants to play them. I've kinda looked into gzipstream, but would that really work? Should I take a different route?
View 6 Replieswhich algorithm used for voice compression mailing and decompression
View 2 RepliesI'm willing to create a program that will determine the size of a file imported in OpenFileDialog After a RAR Compression. I'm not sure what's the ratio of the rar compression,
View 1 RepliesHow can I make a program that stores multiple files in one big file (for transporting). There is no need for compression(takes too long).
also, would it be able to open them in this same program (like a windows explorer folder)?
We need to conditionally disable GZIP compression if user's browser is IE6 (it hangs browser for 5min) in few pages of larger site. Server is IIS7 and has compression for static content turned on - want that compression left working if user agent is not Mozilla/4.0. ASPX code sample anyone? Alternatively, code to conditionally redirect to the same page on another site (could create another virtual site with compression disabled) but need to pass all parameters (GET/POST).
View 1 RepliesI want to check Disk compressed(compress drive to save disk space) property. I have following code to check it. But it always return false. whether it is compress or not.
Dim drive As String = "C"
Dim parameter As String = "win32_logicaldisk.deviceid=""" + drive + ":"""
Dim diskSize As New ManagementObject(parameter)
[Code]....
Private Function Compress(ByVal strInput As String) As Byte()
Try
Dim bytData() As Byte = System.Text.Encoding.UTF8.GetBytes(strInput)
[Code]....
How do i make a program that can compress files, just like programs like winrar do? Every time i try via something as simple as text editor changing something, then changing it back, then it wont work anymore. Any suggestions on how i can make one of these kinds of compression programs?
View 9 RepliesI have a WCF Windows service that provides data to 250+ PDAs via compressed datasets and was looking to redevelop both the service and the mobile application to use Entity Framework 4.x models. In order to keep performance acceptable when sending/receiving data on the PDA I need to keep the data size as small as possible and was wondering if its possible to compress a IEnumerable from the WCF windows service? From previous experience with the datasets I got a 80%+/- compression rate and even decompressing the data on the PDA achieved an overal 50% performance importment so retaining similar levels of performance is critical. Could I use a binary serializer and then compress the stream?
View 1 Repliessome link or could that could explain the way it could be done.
View 1 Repliescan we unzip a zipped folder using microsoft APIs or namespaces perhaps System.IO.Compression. However, it seems to be cumbersome to use them. With a thrid party dll file it works perfectly fine, however i dont want to use it as we dont know what is actually happening inside. Can we have a piece of code which unzips a zipped folder.
View 3 RepliesI'm calling the following method from a button click event to export a datatable to excel. After the export is completed, the excel application object is quit, released and assigned to nothing. But in reality it's not getting released and stays active unless the entire application is closed. So every time the button is clicked for export, a new excel application object keeps on running. The problem doesn't occur if two of the lines from the method below are not used. But I can't omit them as they are really needed. Check the * marked lines.
Code:
''' <summary>
''' Exports data from a datatable to excel.
''' </summary>
[code]....
How to change the frame rate in Visual Basic 2008 Media Player? I have error: System.NullReferenceException was unhandled Message: Object reference not set to an instance of an object. IS there any way to fix this? Here's My Code
[Code]...
Where in Visual Basic 2008 Express Edition Software program do you specify a specific installation directory for a program?
c:Program Filesfinished program
I want to publish my program to try it out on another system and I want to ensure its installed in the directory structure I want.
i'm running Visual Basic 2008 Express Edition (latest service pack ... 9.0.30729.1 SP) on XP Pro SP3 with .Net Framework version 3.5 SP1 I have a rather large project I've imported from Visual Studio 2003 (Standard).The project compiles and runs just fine ... my compiled program itself never crashes.
But while I actually have the code up in the IDE, and simply adding/deleting code the whole IDE will randomly crash (usually without warning) and I loose my changes since last save.If/when I do get some hint of why it crashed, I get a window about illegal whitespace or something.... but that's rare ... usually it just crashes without warning and the whole IDE completely shuts down instantly. just deleting/adding a character is enough to trigger it maybe once every 30 minutes.
This is on a computer that is otherwise very rock solid .... no other program ever crashes, etc.
Is it possible to edit the Windows Form Designer generated code in VS2008?
View 4 RepliesMy some problem for vs 2008 in mobile applications How to learn mobile device board serial number in vb 2008?
View 2 Repliesthis event works ok, but the problem is that I don't know what field was clicked. Should I use objectinfo or something else? VB.net won't recognize for example e.objectinfo.
View 1 RepliesHow can I display column contents of a MS SQL Database on Text Box using VB 2008
View 2 Repliesproblem use Visual Studio 2005,2008 with Microsoft SQL Server 2008 R2 , when open vb.net choose : add new data source and choose database and add connection when choose Microsoft SQL Server (SqlClient) show error this version not supported
View 2 RepliesWhat i need to write is i get different signal from PIC16F877A and through serial port, i need to display diffrent text from different signal, Such as: Signal from portB.1 display 1, signal from portb.2 display 2. Between the microcontroller and serial port im using MAX232.
View 2 RepliesUsing VS2008 as frontend and MS SOL Server2008 as backend... a database is created in MS SQL Server2008(SQLEXPRESS). Now the problem is i am not being able to to load the database created in MS SQL Server2008(SQLEXPRESS) onto VS.Net 2008...
View 32 RepliesI use the 'Process' object to run EXE from my application. It works fine when it run on Windows XP and 2003. When it run on Windows server 2008, it hangs up: the process is stayed in background but never returns. It never goes ahead for the next commands. What could be the reason? [Code]
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