I used over four different methods to get the text from a online text file: www.mysite.com/filedata.txt and overwrite it to another file.
Everything works, but I have only one problem. Everything is written in the first line and not the original format.
Example:
From:
Hello
Hi
Hi
To:
HelloHiHi
Here is just an example of a correct code which I'm using, but it doesn't work:
Using client As New WebClient()
client.DownloadFile("http://www.mystie.com/filedata.txt",
Application.StartupPath & "\file.txt")
End Using
The file is using a different line-break style that is not recognized by the edit control.
There are three different types of line-break styles that are in common usage: the Windows style (CR LF), the Unix style (LF), and the classic Mac style (CR).
Windows controls like the TextBox control naturally require the Windows style, CR LF. The corresponding escape characters for C# would be \r\n; on VB, you use ControlChars.CrLf or vbCrLf. On Unix, LF (\n, or ControlChars.Lf/vbLf) is more commonly encountered. If you are getting a file from an external source, like the Internet, it probably uses Unix-style line breaks, which aren't recognized as line breaks by the Windows TextBox control. The reason it works in what you call "advanced text editors" is that they support all these different styles of line-break characters.
This is exceedingly trivial to fix. Perform a character replacement on the string, replacing LF with CR+LF, before you display it in the TextBox.
' Download the file
Dim path As String = Application.StartupPath & "\file.txt"
Using client As New WebClient()
client.DownloadFile("http://www.mystie.com/filedata.txt", path))
End Using
' Read the file's text in as a string
Dim filedata As String = File.ReadAllText(path)
' Fix up the line endings
filedata = filedata.Replace(ControlChars.Lf, ControlChars.CrLf)
' Display the text in your TextBox
myTextBox.Text = filedata
I managed to solve everything by switching from textbox to richtextbox.
Related
Is it possible for the following code to produce NUL values within a text file?
var temp_str = "123456;1234567"
My.Computer.FileSystem.WriteAllText(Path & "stats.txt", temp_str, False)
It seems simple, but it writes quite often and I'm seeing several files that get accessed by the application that have Strings written to as:
When opening the file with Notepad++. Some other editors show just squares, and it seems like each character is represented by a block/NUL.
So far I've been unable to reproduce this on my test system. I just find the files on a COMX module's file system that's been running in the field and comes back faulty, but I've been seeing enough of these files to make it a problem that needs to be solved.
Does anyone have an idea to prevent this behaviour?
Hard to say what the problem is without more code, but try this if you want to replace the existing contents of the file:
Dim fileContent = "My UTF-8 file contents"
Using writer As IO.StreamWriter = IO.File.CreateText(fullPathIncludingExtension)
writer.Write(fileContent)
End Using
Or this if you want to append UTF-8 text:
Dim newLines = "My UTF-8 content to append"
Using writer As IO.StreamWriter = IO.File.AppendAllText(fullPathIncludingExtension)
writer.Write(fileContent)
End Using
If you want to append Unicode text, you must use a different constructor for StreamWriter:
Using writer As IO.StreamWriter = New IO.StreamWriter("full/path/to/file.txt", True, Text.Encoding.Unicode)
writer.Write(MyContentToAppend)
End Using
Note that the True argument to the constructor specifies that you want to append text.
My program is writing URL-encoded strings into a text file like this one.
topic1=1&topic2=2&topic3=3&
However, I'm trying to reverse the process by opening the same file and breaking that file up in a manner that I can retrieve into name/value-like pairs.
' Final Challenge Category
Dim sr As StreamReader = New StreamReader("./Game" + nudGameNo.Value.ToString() + "/Final/category.txt")
strLine = WebUtility.UrlDecode(sr.ReadLine)
The closest function that I can find to help is HttpUtility.ParseQueryString but I can't seem to run it in a WinForms application. (Even if I use Imports System.Web)
I've also tried to do a .Split with & being the separator, however problems start up if a particular value contains an & of it's own.
Is it possible to break this form of string up?
I have this txt file with the following information:
National_Insurence_Number;Name;Surname;Hours_Worked;Price_Per_Hour so:
eg.: aa-12-34-56-a;Peter;Smith;36;12
This data has been inputed to the txt file through a VB form which works totally fine, the problem comes when, on another form. This is what I expect it to do:
The user will input into a text box the employees NI Number.
The program will then search through the file that NI Number and, if found;
It will fill in the appropriate text boxes with its data.
(Then the program calculates tax and national insurance which i got working fine)
So basically the problem comes telling the program to search that NI number and introduce each ";" delimited field into its corresponding text box.
Thanks for all.
You just need to parse the file like a csv, you can use Microsoft.VisualBasic.FileIO.TextFieldParser to do this or you can use CSVHelper - https://github.com/JoshClose/CsvHelper
I've used csv helper in the past and it works great, it allows you to create a class with the structure of the records in your data file then imports the data into a list of these for searching.
You can look here for more info on TextFieldParser if you want to go that way -
Parse Delimited CSV in .NET
Dim afile As FileIO.TextFieldParser = New FileIO.TextFieldParser(FileName)
Dim CurrentRecord As String() ' this array will hold each line of data
afile.TextFieldType = FileIO.FieldType.Delimited
afile.Delimiters = New String() {";"}
afile.HasFieldsEnclosedInQuotes = True
' parse the actual file
Do While Not afile.EndOfData
Try
CurrentRecord = afile.ReadFields
Catch ex As FileIO.MalformedLineException
Stop
End Try
Loop
I'd recommend using CsvHelper though, the documentation is pretty good and working with objects is much easier opposed to the raw string data.
Once you have found the record you can then manually set the text of each text box on your form or use a bindingsource.
I have a form with several text boxes and I want to write the contents of each of them to a new line in a .txt file. As in, the user fills in a form, and the info is stored in the file. Then I want to be able to retrieve the info from the file into the same text boxes. I am able to do this, so far, but I encounter problems when one of the text boxes is multiline.
Printline(1, txtBox1.text)
Printline(1, txtBox2.text)´which is the multiline one
Printline(1, txtBox3.text)
When I read this back from the file I get the second line of the multiline text box where I want the text from txtBox3 to be.
LineInput(1, txtBox1.text)
LineInput(1, txtBox2.text)
LineInput(1, txtBox3.text)
How can I get all the lines from the multiline text box to write to one line in the file, and then read it back as separate lines in a multiline text box?
I hope I am making sense? I really would like to keep the logic of "one txtBox - one line in the file"
I guess I need to use different methods of writing and reading, but I am not that familiar with this, so any help is much appreciated.
You can rely on the Lines Property in case of having more than one line. Sample code (curTextBox is the given TextBox Control):
Using writer As System.IO.StreamWriter = New System.IO.StreamWriter("path", True)
Dim curLine As String = curTextBox.Text
If (curTextBox.Lines.Count > 1) Then
curLine = ""
For Each line As String In curTextBox.Lines
curLine = curLine & " " & line
Next
curLine = curLine.Trim()
End If
writer.WriteLine(curLine)
End Using
NOTE: this code puts in one line all the text from the given TextBox independently upon its number of lines. If it has more than one line, it includes a blank space to separate the individual lines (all of them fitting in a single line of the file anyway). You might want to change this last feature by adding a different separating character (replace & " " & with the one you want).
One option would be to escape the newlines so that they aren't in the output, then unescape them on reading back in.
Here's some example code that will do this (I've never written VB before, so this probably isn't idiomatic):
' To output to a file:
Dim output As String = TextBox2.Text
' Escape all the backslashes and then the vbCrLfs
output = output.Replace("\", "\bk").Replace(vbCrLf, "\crlf")
' Write the data from output to the file
' To read data from the file:
Dim input As String = ' Put the data from the file in input
' Put vbCrLfs back for \crlf, then put \ for \bk
input = input.Replace("\crlf", vbCrLf).Replace("\bk", "\")
' Put the text back in its box
TextBox2.Text = input
Another option would be to store your data in XML, JSON, or YAML. Any of those are text-based formats that will require a library to parse, but should cleanly handle the multiline text you have, along with providing increased future flexibility.
the next simple code works for me.
Saving multiline text to a single line in a file:
str = Replace(MyTextBox.Text, Chr(13) & Chr(10), "*LineFeed*") 'something recognizable
Print #1, str 'no quotes
To get the string from the file and put it on a TextBox:
Line Input #1, str
MyTextBox.Text = Replace(str, "*LineFeed*", Chr(13) & Chr(10))
Hope this helps
I am using asp.Net MVC application to upload the excel data from its CSV form to database. While reading the csv file using the Stream Reader, if line contains lower case letter followed by Upper case, it splits in two line . EX.
Line :"1,This is nothing but the Example to explanationIt results wrong, testing example"
This line splits to :
Line 1: 1,This is nothing but the Example to explanation"
Line 2:""
Line 3:It results wrong, testing example
where as CSV file generates right as ""1,This is nothing but the Example to explanationIt results wrong, testing example"
code :
Dim csvFileReader As New StreamReader("my csv file Path")
While Not csvFileReader.EndOfStream()
Dim _line = csvFileReader.ReadLine()
End While
Why should this is happening ? how to resolve this.
When a cell in an excel spreadsheet contains multiple lines, and it is saved to a CSV file, excel separates the lines in the cell with a line-feed character (ASCII value 0x0A). Each row in the spreadsheet is separated with the typical carriage-return/line-feed pair (0x0D 0x0A). When you open the CSV file in notepad, it does not show the lone LF character at all, so it looks like it all runs together on one line. So, in the CSV file, even though notepad doesn't show it, it actually looks like this:
' 1,"This is nothing but the Example to explanation{LF}It results wrong",testing example{CR}{LF}
According to the MSDN documentation on the StreamReader.Readline method:
A line is defined as a sequence of characters followed by a line feed ("\n"), a carriage return ("\r"), or a carriage return immediately followed by a line feed ("\r\n").
Therefore, when you call ReadLine, it will stop reading at the end of the first line in a multi-line cell. To avoid this, you would need to use a different "read" method and then split on CR/LF pairs rather than on either individually.
However, this isn't the only issue you will run into with reading CSV files. For instance, you also need to properly handle the way quotation characters in a cell are escaped in CSV. In such cases, unless it's really necessary to implement it in your own way, it's better to use an existing library to read the file. In this case, Microsoft provides a class in the .NET framework that properly handles reading CSV files (including ones with multi-line cells). The name of the class is TextFieldParser and it's in the Microsoft.VisualBasic.FileIO namespace. Here's the link to a page in the MSDN that explains how to use it to read a CSV file:
http://msdn.microsoft.com/en-us/library/cakac7e6
Here's an example:
Using reader As New TextFieldParser("my csv file Path")
reader.TextFieldType = FieldType.Delimited
reader.SetDelimiters(",")
While Not reader.EndOfData
Try
Dim fields() as String = reader.ReadFields()
' Process fields in this row ...
Catch ex As MalformedLineException
' Handle exception ...
End Try
End While
End Using