So, i have this problem for a while and it's truly giving me headaches ... I want to download a string from a website, then save it so a file in my computer that i will create on the spot , let's say the file is D:\cars.txt , the file path by the way is Input(3) .
I tried this but it just won't work!
I ran out of ideas, can't find anything to make it work properly.
If Not IO.File.Exists(Input(3)) Then IO.File.Create(Input(3))
Dim str As String = WC.DownloadString(Input(2))
Using wrtr As IO.StreamWriter = New IO.StreamWriter(Input(3))
wrtr.Write(str)
System.Threading.Thread.Sleep(150)
wrtr.Close()
End Using
It won't write to the file because it's still in use, how can i make it work properly :( ?
IO.File.Create(Input(3) creates or overwrites the file and returns a FileStream. From MSDN:
The FileStream object created by this method has a default FileShare value of None; no other process or code can access the created file until the original file handle is closed.
You can rewrite it as follows,
Dim str As String = WC.DownloadString(Input(2))
System.IO.File.WriteAllText(input(3),str)
Related
I found a similar question but it was 5 years 8 months old, had 2 replies and neither worked for me (VB.Net Read txt file from current directory)
My issue is that when I use the following code:
Dim fileReader As String
fileReader = My.Computer.FileSystem.ReadAllText(Application.StartupPath & "\Username_And_Password_Raw.txt")
Dim usernameAndPassword = Split(fileReader, ",")
I get an error saying:
System.IO.FileNotFoundException: 'Could not find file 'C:\Users\wubsy\source\repos\NEA Stock Page System\NEA Stock Page System\bin\Debug\net6.0-windows\Username_And_Password_Raw.txt'.'
I have tried using all the different Applications.BLANKPath options I can find (ie; StartupPath, CommonAppDataPath, etc.) and they all return essentially the same error only with a different location.
This is the folder layout of my TXT File - I know it's a terrible, incredibly insecure and generally awful way of storing login information but this is just for a NEA so will never ever actually be used
This is the actual path of the TXT File if it helps
C:\Users\wubsy\source\repos\NEA Stock Page System\NEA Stock Page System\Username_And_Password_Raw.txt
The startup path is where your exe is located. That and all supporting files get copied to a binary directory when you compile in visual studio, in your case
C:\Users\wubsy\source\repos\NEA Stock Page System\NEA Stock Page System\bin\Debug\net6.0-windows
But what you're trying to do, reference the file where it sits in your solution, is probably not the best way to do it, and your code above will work (with a change, will mention later) if you change the properties of the file in the solution.
Right click on the file in the Solution Explorer Username_And_Password_Raw.txt, select Properties. Modify Copy to Output Directory to either Copy always / Copy if newer, depending on your requirement. Now that file will copy to the same directory your exe is in, and the code above should work.
Note, when creating a path, don't use string concatenation because you may have too many or too few \; use Path.Combine:
Dim filePath = Path.Combine(Application.StartupPath, "Username_And_Password_Raw.txt"
Dim fileContents = My.Computer.FileSystem.ReadAllText(filePath)
On a button click I have the following code to write what Is in my textboxes.
Dim file As System.IO.StreamWriter
file = My.Computer.FileSystem.OpenTextFileWriter("C:/Users/Nick/Documents/Dra.txt", False)
file.WriteLine(NameBasic)
file.WriteLine(LastBasic)
file.WriteLine(PhoneBasic)
file.WriteLine(NameEmer1)
On my form load, I load what is in the notepad from what was written, It is saying It is already being used(the file) which is true, how can I have two different functions(write, and read) manipulating the same file with out this error?
The process cannot access the file 'C:\Users\Nick\Documents\Dra.txt' because it is being used by another process.
And here is the code for my onformload
Dim read As System.IO.StreamReader
read = My.Computer.FileSystem.OpenTextFileReader("C:/Users/Nick/Documents/Dra.txt")
lblNameBasic.Text = read.ReadLine
I am sort of stuck on this problem, thank you
You need to close the file when you are done writing to it.
Dim file As System.IO.StreamWriter
file = My.Computer.FileSystem.OpenTextFileWriter("C:/Users/Nick/Documents/Dra.txt", False)
file.WriteLine(NameBasic)
file.WriteLine(LastBasic)
file.WriteLine(PhoneBasic)
file.WriteLine(NameEmer1)
file.Close()
To answer your question:
how can I have two different functions(write, and read) manipulating the same file with out this error?
If you really want to simultaneously read and write to the same file from two processes, you need to open the file with the FileShare.ReadWrite option. The My.Computer.FileSystem methods don't do that.¹
However, I suspect that you don't really wan't to do that. I suspect that you want to write and, after you are finished writing, you want to read. In that case, just closing the file after using it will suffice. The easiest way to do that is to use the Using statement:
Using file = My.Computer.FileSystem.OpenTextFileWriter(...)
file.WriteLine(...)
file.WriteLine(...)
...
End Using
This ensures that the file will be closed properly as soon as the Using block is left (either by normal execution or by an exception). In fact, it is good practice to wrap use of every object whose class implements IDisposable (such as StreamWriter) in a Using statement.
¹ According to the reference source, OpenTextFileWriter creates a New IO.StreamWriter(file, append, encoding), which in turn creates a new FileStream(..., FileShare.Read, ...).
After some great arguments made by other users in this question: How to write to a text file inside of the application, I decided to not use a resource file, instead create a file in a folder & then read/write from there.
Although, for some reason, I can't seem to write to the file in question, it keeps throwing an exception telling me the file is already in use by another process.
Here's the code which I use for writing to this file.
If System.IO.File.Exists(credentials) Then
Dim objWriter As New System.IO.StreamWriter(credentials, False)
objWriter.WriteLine(remember)
objWriter.Close()
Else
System.IO.Directory.CreateDirectory(Mid(My.Application.Info.DirectoryPath, 1, 1) & ":\ProgramData\DayZAdminPanel")
System.IO.File.Create(credentials)
Dim objWriter As New System.IO.StreamWriter(credentials, False)
objWriter.WriteLine(remember)
objWriter.Close()
End If
Any ideas on how I can write to the text file in question?
There's a good chance that a previous iteration of your application failed to properly close access to the file in the StreamWriter. Since your constructor is set to overwrite (and not append) to the file, this could be the source.
Try setting up your application with a "Using" statement to properly open/close the file:
If System.IO.File.Exists(credentials) Then
Using objWriter As StreamWriter = New StreamWriter(credentials, False)
objWriter.WriteLine(remember)
objWriter.Close()
End Using
Else
System.IO.Directory.CreateDirectory(Mid(My.Application.Info.DirectoryPath, 1, 1) & ":\ProgramData\DayZAdminPanel")
System.IO.File.Create(credentials)
Using objWriter As StreamWriter = New StreamWriter(credentials, False)
objWriter.WriteLine(remember)
objWriter.Close()
End Using
End If
It does look rather redundant to have a Using block and a close statement, but this ensures access to your file even if an exception occurs.
You are trying to create a directory in the common application data directory. This directory should be found using the Environment class methods and enums because is different between operating systems. However you use the value credentials for the filename. I suppose that you want to store your datafile in the common application directory and not in a place where there is no permission to write data files (Like C:\program files (x86)).
Then, to avoid problems with file stream not correctly closed try to use the Using statement that assures a correct closure and disposal of your file resource (No need to call close inside a Using).
Also, notice that StreamWriter is perfectly capable to create the file if it doesn't exists or if you wish to overwrite the previous contents (passing false for the Append flag).
So your code could be reduced to these lines.
' Get the common application data directory (could be different from Win7 and XP)
Dim workDir = Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData)
' Combine with your own working data directory
workDir = Path.Combine(workdir, "DayZAdminPanel")
' Create if not exists
If Not Directory.Exists(workDir) Then
Directory.CreateDirectory(workDir)
End If
' Create/Overwrite your data file in a subfolder of the common application data folder
Dim saveFile = Path.Combine(workDir, Path.GetFileName(credentials))
Using objWriter = New System.IO.StreamWriter(saveFile, False)
objWriter.WriteLine(remember)
End Using
File.Create returns an opened FileStream that you should be passing into the StreamWriter constructor on the subsequent, rather than passing the filename again, or you can just omit the File.Create call altogether.
You might want to look into a Using block for the StreamWriter so it gets predictably closed.
I have been searching the web looking for a way to open a WORD file from a secure network folder by impersonating a user who has access. The closest I've come to finding the answer was this from 2 years ago:
Impersonating in .net (C#) & opening a file via Process.start
Here is the code that I am using. When I set the arguments = LocalFile_Test, everything works perfectly because the user is accessing the local c:\ that is has access to. But when I set arguments = RemoteFile_Test, Word opens up a blank document which is the same effect as if I put garbage in the arguments. So it appears that it cannot find the file even though when I login with the user/domain/password that I specify in the properties below, I can find that exact file name and it is not empty. Does anything jump out at you right away? I appreciate your time.
Dim LocalFile_Test As String = "C:\New.docx"
Dim RemoteFile_Test As String = "\\Server1\Apps\File\New.docx"
Dim MyStartInfo As New System.Diagnostics.ProcessStartInfo
MyStartInfo.FileName = "C:\Program Files\Microsoft Office\Office12\WINWORD.exe "
MyStartInfo.Arguments = LocalFile_Test
MyStartInfo.LoadUserProfile = True
MyStartInfo.UseShellExecute = False
MyStartInfo.UserName = "specialuser"
MyStartInfo.Domain = "mydomainname"
MyStartInfo.Password = New System.Security.SecureString()
MyStartInfo.Password.AppendChar("p"c)
MyStartInfo.Password.AppendChar("a"c)
MyStartInfo.Password.AppendChar("s"c)
MyStartInfo.Password.AppendChar("s"c)
Process.Start(MyStartInfo)
My understanding is that you are trying to get a password protected file from a server, and when you do process start, it just opens up a blank word doc. I think the error is how you are trying to get the file, I think you have to map the actual physical path of the file on the server, like
System.Web.HttpContext.Current.Server.MapPath("\\Server1\Apps\File\New.docx")
From there, I am fairly certain, you need to create network credentials for the user like
System.Net.NetworkCredential=New NetworkCredential(userName:=, password:=)
Finally, once that is done, you can either write the file, or transmit the file like so...
System.Web.HttpContext.Current.Response.TransmitFile(file name)
System.Web.HttpContext.Current.Response.WriteFile(file name)
Then,once you get the file, you can try to open it with process start.
Hope that helps, let me know if what I said doesn't work.
Right now i have a line of code, in vb, that calls a text file, like this:
Dim fileReader As String
fileReader = My.Computer.FileSystem.ReadAllText("data5.txt")
data5.txt is a resource in my application, however the application doesn't run because it can't find data5.txt. I'm pretty sure there is another code for finding a .txt file in the resource that i'm overlooking, but i can't seem to figure it out. So does anyone know of a simple fix for this? or maybe another whole new line of code? Thanks in advance!
If you added the file as a resource in the Project + Properties, Resources tab, you'll get its content by using My.Resources:
Dim content As String = My.Resources.data5
Click the arrow on the Add Resource button and select Add Existing File, select your data5.txt file.
I'm assuming that the file is being compiled as an Embedded Resource.
Embedded Resources aren't files in the filesystem; that code will not work.
You need to call Assembly.GetManifestResourceStream, like this:
Dim fileText As String
Dim a As Assembly = GetType(SomeClass).Assembly
Using reader As New StreamReader(a.GetManifestResourceStream("MyNamespace.data5.txt"))
fileText = reader.ReadToEnd()
End Using
First, go to project resources (My Project --> Resources), and drag-and-drop your file, say "myfile.txt", from the file system to the resourses page.
Then:
Imports System.IO
...
Dim stream As New MemoryStream(My.Resources.myfile)
Dim reader As New StreamReader(stream)
Dim s As String = reader.ReadToEnd()