I have a file I am trying to read and disply results into a text box. The file has no extension, but it is a 'data' file per the website (www.checkfiletype.com).
Here is a screen shot of how the file looks in a online reader, it looks like hex?
I have tried a stream reader, and gives nothing in results. Last method I tried was a BinaryReader, that I have never used before. The results from this is a "0" into the text box. Given that I have never used the BinaryReader function, I am sure I did something wrong with it.
Using reader As New BinaryReader(File.Open("C:\Users\jefhill\Desktop\CMOSDATA", FileMode.Open))
Dim pos As Integer = 0
Dim length As Integer = reader.BaseStream.Length
While pos < length
' Read the integer.
Dim value As Integer = reader.ReadInt32()
' Write to screen.
TextBox1.Text = value
' Add length of integer in bytes to position.
pos += 4
End While
End Using
Any help would be greatly appreciated.
EDIT
I tried using a basic StreamReader. With this, nothing happens, as in no errors, just puts nothing(blank) into the textbox.
Dim file As String = "C:\Users\jefhill\Desktop\CMOSDATA"
Dim reader As New System.IO.StreamReader(file)
TextBox1.Text = reader.ReadToEnd
reader.Close()
The file is not a text file, and cannot be directly displayed in a TextBox. You will need to find the format of the file and convert it to text in order to display it in a TextBox.
Related
I need my application to find and modify a text string in a .swp file (generated by VBA for SOLIDWORKS). If I open said file as text in Notepad++, most of the text looks like this (this is an excerpt):
Meaning there is readable text, and symbols that appear as NUL, BEL, EXT and so on, depending on selected encoding. If I make my changes via Notepad++ (finding and changing "1.38" to "1.39"), there are no issues, the file can be opened via SOLIDWORKS and is still recognized as valid. After all, I don't need to modify these non-readable bits. However, if I do the same modification in my VB.NET application,
Dim filePath As String = "D:\OneDrive\Desktop\launcher macro.swp"
Dim fileContents As String = My.Computer.FileSystem.ReadAllText(filePath, Encoding.UTF8).Replace("1.38", "1.39")
My.Computer.FileSystem.WriteAllText(filePath, fileContents, Encoding.UTF8)
then the file gets corrupted, and is no longer recognized by SOLIDWORKS. I suspect this is because ReadAllText and WriteAllText cannot handle whatever data is in these non-readable bits.
I tried many different encodings, but it seems to make no difference. I am not sure how Notepad++ does it, but I can't seem to get the same result in my VB.NET application.
Can someone advise?
Thanks to #jmcilhinney, this is a solution that worked for me - reading file as bytes, converting to string, and then saving, using ANSI formatting:
Dim file_name As String = "D:\OneDrive\Desktop\launcher macro.swp"
Dim fs As New FileStream(file_name, FileMode.Open)
Dim binary_reader As New BinaryReader(fs)
fs.Position = 0
Dim bytes() As Byte = binary_reader.ReadBytes(binary_reader.BaseStream.Length)
Dim fileContents As String = System.Text.Encoding.Default.GetString(bytes)
fileContents = fileContents.Replace("1.38", "1.39")
binary_reader.Close()
fs.Dispose()
System.IO.File.WriteAllText(file_name, fileContents, Encoding.Default)
I am trying to read specific lines from a text file in an array (e.g. line 16,25,34, and so on). Could you please let me know if it is possible and how that could be done?
Thanks in advance,
Pouya
Yes it is possible. Since this is not a code based will elaborate how to achieve that. This will depends on the size of your target file. If the size in not to large for your PC's memory then you can read the whole textfile while reading keep the count.
Then start when the file has been read to end to go through your lines using regex.
Check:
VB.NET Read Certain text in a text file
your solution is here:
http://www.dreamincode.net/forums/topic/56497-go-to-a-particular-line-in-a-text-file-using-vbnet/
How to read a specific line from a text file in VB
Ok, here's I've also quoted the code to help you from the second last like I provided above. I'm sure you know how to get data from an Array so instead of line you will add your array.
Public Function
ReadSpecifiedLine(ByVal line As
Integer) As String
'create a variable to
hold the contents of the file
Dim contents As String = String.Empty
'create a variable to
hold our line contents
Dim lineText As String =
String.Empty
' always use a
try...catch to deal
' with any exceptions
that may occur
Try
'Using lineByLine As New IO.StreamReader(_fileName)
Dim lineCount As Integer = 0
While Not lineByLine.EndOfStream
lineByLine.ReadLine ()
If lineCount = line Then
' you can replace the line variable above or use the And Or to match the lines from your array.
lineText = lineByLine.ReadLine()
End If
lineCount += 1
End While
End Using
Catch ex As FileNotFoundException
lineText = String.Empty
_returnMessage = ex.Message
Catch ex As Exception
' deal with any errors
_returnMessage = ex.Message
End Try
Return lineText
End Function
Hope this helps you.(Sorry having some problems in code formatting it some part maybe not formeted, or visible. If End Function is not visible please refer to the link. I've tried so many times to formet this but it not properly formeted, I'm using a Mobile phone.)
I am currently trying to manipulate a line in a file that we are using to retain data, using comma delimiters. For example -
121,1212, XJAY,Sean K,Kean S,AAAA-BBBB-AAAA-BBBB-AAAA
12456,987654,WYST,Steve Jobs,Bill Gates,CAAA-BBBB-AAAA-BBBB-AAAA
If I assume that the last line is always a unique code, is it possible to identify that line in the text file and append it with another field?
Prior research has been reading through the APIs for StreamReader and StreamWriter, and looking through other StackOverflow questions, however most questions seem focused on just appending to the end of the file, or in different languages!
As always thank you for your time, and if there is anything I've left off please let me know!
You can't manipulate a line in a file in any reasonably easy way.
There are no methods to work with lines in a file, because files are not line based. They are not even character based. The bytes in the file are decoded into characters, then the line break characters are recognised and the characters can be split into lines.
The easiest way to manipulate a line is to read the entire file into a string array, change the string that you want change, then write the entire string array to the file.
Example:
Dim fileName As String = "c:\data.txt"
Dim lines As String() = File.ReadAllLines(fileName)
For i As Integer = 0 To lines.Length - 1
Dim line As String = lines(i)
If line.StartsWith("12456,") Then
lines(i) = line & ",More data"
End If
Next
File.WriteAllLines(fileName, lines)
If you are looking for a way to parse Each line with StreamReader and StreamWriter: Here it is:
'You will need Imports System.IO
Dim TheNewFile As String
Dim MyLine As String
Dim MyStream2 As New FileStream("C:\Your Directory\YourFile.txt", FileMode.Open)
Dim MyReader As New StreamReader(MyStream2)
Dim MySettings As New StringReader(MyReader.ReadToEnd)
MyReader.BaseStream.Seek(0, SeekOrigin.Begin)
MyReader.Close()
MyStream2.Close()
Try
Do
MyLine = MySettings.ReadLine
'This if statement is an exit parameter. It can be if it contains or if 5 consecutive lines are nothing. It could be a number of things
If MyLine Is Nothing Then Exit Do
'This is the file you will write. You could do if MyLine = "Test" Then ........... append whatever and however you need to
TheNewFile = TheNewFile & MyLine & vbCrLf
Loop
Catch ex As Exception
MsgBox(ex.ToString())
End Try
'-----------------Write The new file!!!----------------
Dim MyStream3 As New FileStream("C:\Where you want to write New File\NewFileName.txt", FileMode.Create)
Dim MyWriter3 As New StreamWriter(MyStream3)
MyWriter3.Write(TheNewFile & "Test")
MyWriter3.Close()
MyStream3.Close()
I simply need to read lines from a text file and show them. When I run this I can see that id does what I want, but after it reads the last value it just shows a blank form on my screen and does not move on. It seems like it can't find the end of the file or something. I don't get an error.
Using sr As New System.IO.StreamReader(Application.StartupPath & "\myfile.cfg")
Dim Line As String = ""
Dim i As Integer = 0
Dim temp_array As Array
Do While Line IsNot Nothing
Line = sr.ReadLine
temp_array = Line.Split("=")
'MessageBox.Show(temp_array(0))
Loop
End Using
That is bad code because you're actually going to use Line before testing whether it's Nothing. Here are two good options for looping through the lines of a text file:
Using reader As New StreamReader(filePath)
Dim line As String
Do Until reader.EndOfStream
line = reader.ReadLine()
'...
Loop
End Using
For Each line In File.ReadLines(filePath)
'...
Next
As you can see, the second is far more concise but it does require .NET 4.0 or later.
Not sure if this is something really simple that I haven't noticed. Or just a simple try/catch (I guess most likely).
I have a textbox on a form. It takes in data from another text file which is very large (lets assume 1Mb) and in a lot of cases it can take it but in some cases the program crashes when loading the file.
How can I handle this?
You could try to read the file size of the text file before loading it into your text box. If the length of the file is greater than the capacity of your text box, you can prevent the text box from being filled.
You can use a function like File.ReadAllLines to determine the size of the text file.
Dim AppDataLocation As String = "C:\Files\TestFiles\"
Dim sourceDirectoryInfo As New System.IO.DirectoryInfo(AppDataLocation)
For Each fileSystemInfo As System.IO.FileSystemInfo In _
SourceDirectoryInfo.GetFileSystemInfos
Dim FileText As String = System.IO.File.ReadAllText _
(AppDataLocation & fileSystemInfo.Name)
Next
Alternately, you can use FileInfo.Length as seen in this example here.
Dim file As New FileInfo("file.txt")
Dim sizeInBytes As Long = file.Length