I am trying to make a patching system or an updater if you will for my program. What I want it to do is download the patch list which is in a specific form in the text file.
Like this:
1 http://127.0.0.1:8080/patches/test1.rar
2 http://127.0.0.1:8080/patches/test2.rar
3 http://127.0.0.1:8080/patches/test3.rar
It's a tab in between 1 and the link.
And then I want it to check if the version number of the launcher or program at the moment matches the LAST patch in the PatchList.txt file. The last patch is version 3 and the launcher version at the moment is 0.
So if it doesn't match then it should start downloading one by one the patches. From patch 1 to patch 3.
I thought a loop statement would be best for it so I came up with this idea:
Make it download the PatchList.txt and then read each line individually. After it reads a line it will split where tab is so there will be two variables Version and PatchURL.
It will then check Version to see if it matches the launcher version and if it doesn't then it will download files from the PatchURL and apply it and then set the launcher version to the version of the current patch and then check again, if the version number and if it does match then there will be no updates so it will finish.
I don't know exactly how to put it into code. I have been trying for ages to be able to Download the txt file and read it line by line but I haven't been able to. I have tried many different things from StreamReader to StringReader and a bunch of other stuff.
I'd appreciate any help. This is very frustrating for me.
If you just want to download the file and read it in again, it's as easy as
My.Computer.Network.DownloadFile("http://your_url.txt", "local_tmp_path")
If you don't want to save the file on disk but read it in memory, you could use something like this:
Dim httpRequest = DirectCast(WebRequest.Create("http://your_url.txt"), HttpWebRequest)
Dim httpResponse = DirectCast(httpRequest.GetResponse(), HttpWebResponse)
Dim line As String
Using responseStream = httpResponse.GetResponseStream(), sr = New StreamReader(responseStream)
Do
line = sr.ReadLine()
If line IsNot Nothing Then
Dim s = line.Split(new String() {" "}, StringSplitOptions.RemoveEmptyEntries)
Dim version = s(0)
Dim path = s(1)
'Do something'
End If
Loop Until line Is Nothing
End Using
If you try to implement an update system for your software, better have a look at ClickOnce first.
What do you mean by download?
I would try the solution mentioned here.
How to read a specific line from a text file in VB
Otherwise, I would reccommend using XML for the version file and just deserializing it.
Related
I am upgrading some older iTextSharp code to the new iText 7 libraries. I am having a lot of trouble determining the proper way to merge 2 PDF MemoryStreams into one PDF MemoryStream that contains all the pages from both source PDF MemoryStreams. It seems simple and I think the code below is set up properly but the resulting PDF memory stream only contains the first file. The second PDF file is never present and never concatenated to the first.
I have found multiple ways documented on the Internet as the "proper" way to do the merge. The actual sample code with iText 7 seems to be unusually complex (in that is mixes multiple concepts into one sample repeatedly - as in doesn't reduce the concept to the simplest possible code), and seems to fail to demonstrate simple concepts. For instance, their PDFMerge documentation has no sample code at all in the documentation (nor does anything else I looked at in the class documentation). The examples they have online actually always mix merging from files (not MemoryStreams) with other concepts like adding page numbers or adding Table of Contents. So they never just show one concept and they never start with anything other than files. My PDFs are coming out of a database and we just need to merge them into one PDF memory stream and save it back out. My concern is that maybe I am not creating the MemoryStream properly when I initialize the PDFWriter. As none of their samples ever do anything but initial with an actual file, I was unable to confirm this was done properly. I also fully qualified all objects in the code because I want to leave the old iTextSharp code in place while I am upgrading to the new iText 7. This was done to make sure an iTextSharp object of the same name wasn't inadvertently being unknowingly used.
Also, in the interest of making the source as easy as possible to read I removed some of the declarations and initialization of objects being used. Everything was traced through and all values are fully loaded with proper values as you trace through the code. The only problem is that the second PDFMerge doesn't seem to do anything. I am assuming the problem is that I didn't prepare the PDF objects properly or that I have to do something special with the PDFWriter on the Destination PDF Document (p_pdfDocument) before the second PDF is written out with the PDFMerge object.
Dim p_bResult As Boolean = False
Dim p_bArray As Byte() = Nothing
Dim p_memStream As New System.IO.MemoryStream
Dim p_pdfWriter As New iText.Kernel.Pdf.PdfWriter(p_memStream)
Dim p_pdfDocument As New iText.Kernel.Pdf.PdfDocument(p_pdfWriter)
Dim p_pdf1Stream As New System.IO.MemoryStream(CType(p_cImage1.ImageFile, Byte()))
Dim p_pdf2Stream As New System.IO.MemoryStream(CType(p_cImage2.ImageFile, Byte()))
Dim p_pdf1Reader As New iText.Kernel.Pdf.PdfReader(p_pdf1Stream)
Dim p_pdf2Reader As New iText.Kernel.Pdf.PdfReader(p_pdf2Stream)
Dim p_pdf1Document As New iText.Kernel.Pdf.PdfDocument(p_pdf1Reader)
Dim p_pdf2Document As New iText.Kernel.Pdf.PdfDocument(p_pdf2Reader)
Dim p_pdfMerger As New iText.Kernel.Utils.PdfMerger(p_pdfDocument)
p_pdfMerger.Merge(p_pdf1Document, 1, p_pdf1Document.GetNumberOfPages())
p_pdfMerger.Merge(p_pdf2Document, 1, p_pdf2Document.GetNumberOfPages())
'Problem is here... the array only has the first PDF in it
'The second p_pdfMerger.Merge didn't seem to do anything
p_bArray = p_memStream.ToArray
p_pdf1Document.Close()
p_pdf2Document.Close()
p_pdfDocument.Close()
I expected the 2 source PDF MemoryStreams to be present in the destination MemoryStream but it only contains the first PDF in it.
Edit:
I changed the ending to...
p_pdfMerger.Merge(p_pdf1Document, 1, p_pdf1Document.GetNumberOfPages())
p_pdfMerger.Merge(p_pdf2Document, 1, p_pdf2Document.GetNumberOfPages())
p_cImage1.PageCount = p_pdfDocument.GetNumberOfPages()
p_pdfDocument.Close()
p_bArray = p_memStream.ToArray
p_pdf1Document.Close()
p_pdf2Document.Close()
Thing is that the p_pdfDocument.GetNumberOfPages() is correct but bytes are still just first PDF document when saved to database and viewed.
I tested your use case, condensing your code a bit, reading the input memory streams from files, and writing the output memory stream to a file as I don't have your database environment:
Using MemoryStream As New MemoryStream,
Pdf1MemoryStream As New MemoryStream(File.ReadAllBytes(MY_FIRST_PDF_FILE)),
Pdf2MemoryStream As New MemoryStream(File.ReadAllBytes(MY_SECOND_PDF_FILE))
Using PdfDocument As New PdfDocument(New PdfWriter(MemoryStream)),
Pdf1 As New PdfDocument(New PdfReader(Pdf1MemoryStream)),
Pdf2 As New PdfDocument(New PdfReader(Pdf2MemoryStream))
Dim Merger As New PdfMerger(PdfDocument)
Merger.Merge(Pdf1, 1, Pdf1.GetNumberOfPages)
Merger.Merge(Pdf2, 1, Pdf2.GetNumberOfPages)
End Using
Dim PdfBytes As Byte() = MemoryStream.ToArray()
Using FileStream As Stream = File.Create("TwoPdfsMergedInMemoryStream.pdf")
FileStream.Write(PdfBytes, 0, PdfBytes.Length)
End Using
End Using
As result I got the contents of both source files in TwoPdfsMergedInMemoryStream.pdf as it should be. Concerning your observation
Thing is that the p_pdfDocument.GetNumberOfPages() is correct but bytes are still just first PDF document when saved to database and viewed.
therefore, I would assume that p_bArray does contain a PDF with the contents of both your source PDFs but that there is an issue in saving to database or viewing.
To test this you could save the contents of the byte array to a file somewhere like I do above; then you can check what really is in the array.
I had created and text file using (AFL SCRIPTING LANGUAGE) this script will update (write) to a text file every 5 seconds. I will try to read file using vb.net, when I run the vb.net code form visual studio, everything works fine but (AFL script not able to update the text file), here is my vb.net code:
Dim FILE_NAME As New FileStream("C:\myreport\myfile.TXT", FileMode.Open, FileAccess.Read, FileShare.Read)
REM Dim FILE_NAME As String = "C:\myreport\myfile.TXT"
REM Dim TextLine As String
REM If System.IO.File.Exists(FILE_NAME) = True Then
Dim objReader As New System.IO.StreamReader(FILE_NAME)
Do While objReader.Peek() <> -1
MYSTRING(I) = objReader.ReadLine()
I = I + 1
Loop
REM End If
When I run the code above, ( AFL script not able to update the text file),
Put simply:
When I run the vb.net code (for accessing the text file), AFL script not able to update.
I had share read/write the folder (where the text file exists), no effect, same problem I am facing.
Unchecked "Enable visual studio hosting process", still problem not solved.
In .NET, the FileSystemWatcher class can help you with this problem. You can read the file each time the file watcher says that the files has changed. Here is the reference documentation for it.
You cannot read and write to a file from two processes at the same time. Well, technically you can, but it can lead to a race condition which is bad.
You need to implement some kind of shared locking mechanism around the file to prevent your two programs from fighting over it. Or, if you can guarantee that the consumer VB.NET program will have the file open for less than 5 seconds, you can go with MrAxel's solution and simply have the VB.NET program read the file every time it is updated.
The below given code is returning corrupted data to the variable 'mystr'
like
PK ! ��fѲ � [Content_Types].xml �(� �UMk�#���^��N%�9�ɱ
It was reading the word files correctly. Suddenly it started happening without any change in code or software versions or source files!! Any word file I try to run through the below code gives the same corrupted output. I'm able to open the file in MsWord without any issue.
Dim myStreamReader As System.IO.StreamReader
Dim myStr As String
myStreamReader = System.IO.File.OpenText("c:\test.docx")
myStr = myStreamReader.ReadToEnd()
myStreamReader.Close()
Any suggestions why it is happening ?
You can't read a Word document using the StreamReader class as the file itself isn't plain text (it contains the data you find 'corrupted').
This link will help you reading text from a Word document.
I've been trying to use StreamReader to read a log file. I cannot verify what it is encoded in, as when I open it in notepad++ and select ANSI encoding, I get this result:
I'm getting the characters needed when using ANSI but they are followed by things like [NULL][EOT][SOH][NUL][SI]
When I try and read the file in VB (using StreamReader or ReadAll) with ANSI encoding selected the resulting string I get back is completely wrong.
How could I read a file like this in VB.net?
You could use the IO.File.ReadAllText("File Location", encoding as System.Text.Encoding) method,
Dim textFromFile as string = IO.File.ReadAllText("C:\Users\Jason\Desktop\login20130417.rdb", System.Text.Encoding.ASCII) 'Or Unicode, UFT32, UFT8, UFT7, BigEndianUnicode or default. Default is ANSI.
If you still don't get the text you need by using the default encoding (ANSI), then you can always try the other 6 different encoding methods.
Update...
It appears that your file is corrupt, using the code below I was able to get a binary representation of whatever is in the file, I got this,
1111111111111101000001110000010000000000000001010000000000010011000000000000100000000000000111100000000000100110000000000011100000000010000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000110000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000111111111111110100000111000001000000000000000101000000000001001100000000000010000000000000011110000000000010100000000000111111111111110100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000110011100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
The massive amount of null data would suggest that the file is corrupt, which would also explain why we are not getting a lot of data whenever we try to read the file.
The code,
Dim fileData As String = IO.File.ReadAllText("C:\Users\Jason\Desktop\login20130417.rdb")
Dim i As Integer = 0
Dim binaryData As String = ""
Dim ch As String = ""
Do Until i = fileData.Length
ch = fileData.Chars(i)
bin = bin & System.Convert.ToString(AscW(ch), 2).PadLeft(8, "0")
i = i + 1
Loop
As #Daniel A. White suggested in his comment, that file does not appear to be encoded like a "normal" text file. A StreamReader will not work in this situation. I would attempt to use a BinaryReader.
Rdb file? Never heard of it. Quick google makes it less clear - n64 database file, Darkbot, etc...
However considering the name you have, and the general look of the opened file, i would say its a binary file.
If you want to read the file in vb.net you'll need a library of sorts, and i can't help you with one until you are able to shed some light on what the file may be, or what it was created with.
I have written a vb program a few years ago and now as I get started with vb again i am hitting a "snag". With sequential files. I am trying to load a file in to the vb program with the file dialog box.
NOTE:I am using structures
Dim FileDialog as new openFileDialog
Dim MyStream as Stream = nothing
Dim FileLocation as string 'this is to save the file location
if( FileDialog.ShowDialog() = DialogResults.OK)Then
FS = new FileStream(FileLocation, FileMode.open, fileaccess.Read)
BF = new BinaryFromatter
While FS.Position < FS.Length
Dim temp as unit
...'Please note that this is where the file reads the structures data.It is to much code to write in.
When I run the program I can create a file and save it with the data in and I can load it with the Dialog box, The problem is when I run the program again and try to load it. It just wont run the file or load it(Remember I created the file with this program and saved)
How do I get this to work?
Make sure you have closed the file after writing and reading the data the first time, and make sure you are using the correct path (FileLocation).
Exit Visual Studio between the first and second times you run the program. If it works then, then you know you are not closing the file properly.
Set a breakpoint at the new FileStream assignment and check the value of FileLocation. Is it the same as it was when the file was written?
Check the error message, if there is one, and see if that tells you anything.