I'm trying to get my streamwriter to add text onto the end of the text file but for some reason, it is just replacing the text with whatever I have entered. Any help is appreciated to fix this.
StreamWriter sw = new StreamWriter(Server.MapPath("~") + "/App_Data/blogMessages.txt");
sw.WriteLine(postTextBox.Text);
sw.Close();
you can use a over ridden method for stream writer
StreamWriter sw = new StreamWriter(Server.MapPath("~") + "/App_Data/blogMessages.txt", true);
this will apppend your text
You need to use the overload version of the StreamWriter constructor that take an extra parameter to configure overwrite or append to the stream. And please add the using statement
using(StreamWriter sw = new StreamWriter(Server.MapPath("~") +
"/App_Data/blogMessages.txt", true))
{
sw.WriteLine(postTextBox.Text);
}
The using statement allows for the correct close and dispose of the stream also in case you get an exception when opening or writing
try this
using (System.IO.TextWriter tw = new System.IO.StreamWriter(#"D:\TEMP\IEALog\path.txt", true))
{
tw.WriteLine(message + "Source ;- " + source + "StackTrace:- " + exc.StackTrace.ToString());
}
Related
I need the StreamWriter to write a new single line in my textfile, when I write this:
using (StreamWriter sw = new StreamWriter(#"C:\Users\razer\Desktop\Inlägg.txt"))
{
sw.WriteLine(textBox1.Text);
}
It overwrites the previously written line in the textfile
To summarize: I need the streamwriter to write a new line and not overwrite what was written in the textfile earlier.
There are no error messages, I only need to change the writing mechanics
Simply do this in order to append to the file rather than overwrite. It's the true after your txt file that does this.
using (StreamWriter sw = new StreamWriter(#"C:\Users\razer\Desktop\Inlägg.txt"), true))
{
sw.WriteLine(textBox1.Text);
}
Alternatively, you could use the following code:
Pre-C# 8
using (var sw = File.AppendText(#"C:\Users\razer\Desktop\Inlägg.txt"))
{
sw.WriteLine();
}
C# 8
using var sw = File.AppendText(#"C:\Users\razer\Desktop\Inlägg.txt");
sw.WriteLine();
UPDATE
A shorter way :)
File.AppendAllText(#"C:\Users\razer\Desktop\Inlägg.txt", "text");
I'm trying to detect if a file exists at runtime, if not, create it. However I'm getting this error when I try to write to it:
The process cannot access the file 'myfile.ext' because it is being used by another process.
string filePath = string.Format(#"{0}\M{1}.dat", ConfigurationManager.AppSettings["DirectoryPath"], costCentre);
if (!File.Exists(filePath))
{
File.Create(filePath);
}
using (StreamWriter sw = File.AppendText(filePath))
{
//write my text
}
Any ideas on how to fix it?
File.Create(FilePath).Close();
File.WriteAllText(FileText);
I want to update this answer to say that this is not really the most efficient way to write all text. You should only use this code if you need something quick and dirty.
I was a young programmer when I answered this question, and back then I thought I was some kind of genius for coming up with this answer.
The File.Create method creates the file and opens a FileStream on the file. So your file is already open. You don't really need the file.Create method at all:
string filePath = #"c:\somefilename.txt";
using (StreamWriter sw = new StreamWriter(filePath, true))
{
//write to the file
}
The boolean in the StreamWriter constructor will cause the contents to be appended if the file exists.
When creating a text file you can use the following code:
System.IO.File.WriteAllText("c:\test.txt", "all of your content here");
Using the code from your comment. The file(stream) you created must be closed. File.Create return the filestream to the just created file.:
string filePath = "filepath here";
if (!System.IO.File.Exists(filePath))
{
System.IO.FileStream f = System.IO.File.Create(filePath);
f.Close();
}
using (System.IO.StreamWriter sw = System.IO.File.AppendText(filePath))
{
//write my text
}
FileStream fs= File.Create(ConfigurationManager.AppSettings["file"]);
fs.Close();
File.Create returns a FileStream. You need to close that when you have written to the file:
using (FileStream fs = File.Create(path, 1024))
{
Byte[] info = new UTF8Encoding(true).GetBytes("This is some text in the file.");
// Add some information to the file.
fs.Write(info, 0, info.Length);
}
You can use using for automatically closing the file.
I updated your question with the code snippet. After proper indenting, it is immediately clear what the problem is: you use File.Create() but don't close the FileStream that it returns.
Doing it that way is unnecessary, StreamWriter already allows appending to an existing file and creating a new file if it doesn't yet exist. Like this:
string filePath = string.Format(#"{0}\M{1}.dat", ConfigurationManager.AppSettings["DirectoryPath"], costCentre);
using (StreamWriter sw = new StreamWriter(filePath, true)) {
//write my text
}
Which uses this StreamWriter constructor.
I know this is an old question, but I just want to throw this out there that you can still use File.Create("filename")", just add .Dispose() to it.
File.Create("filename").Dispose();
This way it creates and closes the file for the next process to use it.
This question has already been answered, but here is a real world solution that
checks if the directory exists and adds a number to the end if the text file
exists. I use this for creating daily log files on a Windows service I wrote. I
hope this helps someone.
// How to create a log file with a sortable date and add numbering to it if it already exists.
public void CreateLogFile()
{
// filePath usually comes from the App.config file. I've written the value explicitly here for demo purposes.
var filePath = "C:\\Logs";
// Append a backslash if one is not present at the end of the file path.
if (!filePath.EndsWith("\\"))
{
filePath += "\\";
}
// Create the path if it doesn't exist.
if (!Directory.Exists(filePath))
{
Directory.CreateDirectory(filePath);
}
// Create the file name with a calendar sortable date on the end.
var now = DateTime.Now;
filePath += string.Format("Daily Log [{0}-{1}-{2}].txt", now.Year, now.Month, now.Day);
// Check if the file that is about to be created already exists. If so, append a number to the end.
if (File.Exists(filePath))
{
var counter = 1;
filePath = filePath.Replace(".txt", " (" + counter + ").txt");
while (File.Exists(filePath))
{
filePath = filePath.Replace("(" + counter + ").txt", "(" + (counter + 1) + ").txt");
counter++;
}
}
// Note that after the file is created, the file stream is still open. It needs to be closed
// once it is created if other methods need to access it.
using (var file = File.Create(filePath))
{
file.Close();
}
}
I think I know the reason for this exception. You might be running this code snippet in multiple threads.
you can just use using keyword around File.Create(path) to finalize the process
using(File.Create(path));
Try this: It works in any case, if the file doesn't exists, it will create it and then write to it. And if already exists, no problem it will open and write to it :
using (FileStream fs= new FileStream(#"File.txt",FileMode.Create,FileAccess.ReadWrite))
{
fs.close();
}
using (StreamWriter sw = new StreamWriter(#"File.txt"))
{
sw.WriteLine("bla bla bla");
sw.Close();
}
I want to append lines to my file. I am using a StreamWriter:
StreamWriter file2 = new StreamWriter(#"c:\file.txt");
file2.WriteLine(someString);
file2.Close();
The output of my file should be several strings below each other, but I have only one row, which is overwritten every time I run this code.
Is there some way to let the StreamWriter append to an existing file?
Use this instead:
new StreamWriter("c:\\file.txt", true);
With this overload of the StreamWriter constructor you choose if you append the file, or overwrite it.
C# 4 and above offers the following syntax, which some find more readable:
new StreamWriter("c:\\file.txt", append: true);
using (FileStream fs = new FileStream(fileName,FileMode.Append, FileAccess.Write))
using (StreamWriter sw = new StreamWriter(fs))
{
sw.WriteLine(something);
}
I assume you are executing all of the above code each time you write something to the file. Each time the stream for the file is opened, its seek pointer is positioned at the beginning so all writes end up overwriting what was there before.
You can solve the problem in two ways: either with the convenient
file2 = new StreamWriter("c:/file.txt", true);
or by explicitly repositioning the stream pointer yourself:
file2 = new StreamWriter("c:/file.txt");
file2.BaseStream.Seek(0, SeekOrigin.End);
Try this:
StreamWriter file2 = new StreamWriter(#"c:\file.txt", true);
file2.WriteLine(someString);
file2.Close();
Replace this:
StreamWriter file2 = new StreamWriter("c:/file.txt");
with this:
StreamWriter file2 = new StreamWriter("c:/file.txt", true);
true indicates that it appends text.
Actually only Jon's answer (Sep 5 '11 at 9:37) with BaseStream.Seek worked for my case. Thanks Jon! I needed to append lines to a zip archived txt file.
using (FileStream zipFS = new FileStream(#"c:\Temp\SFImport\test.zip",FileMode.OpenOrCreate))
{
using (ZipArchive arch = new ZipArchive(zipFS,ZipArchiveMode.Update))
{
ZipArchiveEntry entry = arch.GetEntry("testfile.txt");
if (entry == null)
{
entry = arch.CreateEntry("testfile.txt");
}
using (StreamWriter sw = new StreamWriter(entry.Open()))
{
sw.BaseStream.Seek(0,SeekOrigin.End);
sw.WriteLine("text content");
}
}
}
Use this StreamWriter constructor with 2nd parameter - true.
Another option is using System.IO.File.AppendText
This is equivalent to the StreamWriter overloads others have given.
Also File.AppendAllText may give a slightly easier interface without having to worry about opening and closing the stream. Though you may need to then worry about putting in your own linebreaks. :)
One more simple way is using the File.AppendText it appends UTF-8 encoded text to an existing file, or to a new file if the specified file does not exist and returns a System.IO.StreamWriter
using (System.IO.StreamWriter sw = System.IO.File.AppendText(logFilePath + "log.txt"))
{
sw.WriteLine("this is a log");
}
Replace this line:
StreamWriter sw = new StreamWriter("c:/file.txt");
with this code:
StreamWriter sw = File.AppendText("c:/file.txt");
and then write your line to the text file like this:
sw.WriteLine("text content");
You can use like this
using (System.IO.StreamWriter file =new System.IO.StreamWriter(FilePath,true))
{
`file.Write("SOme Text TO Write" + Environment.NewLine);
}
I'm trying to detect if a file exists at runtime, if not, create it. However I'm getting this error when I try to write to it:
The process cannot access the file 'myfile.ext' because it is being used by another process.
string filePath = string.Format(#"{0}\M{1}.dat", ConfigurationManager.AppSettings["DirectoryPath"], costCentre);
if (!File.Exists(filePath))
{
File.Create(filePath);
}
using (StreamWriter sw = File.AppendText(filePath))
{
//write my text
}
Any ideas on how to fix it?
File.Create(FilePath).Close();
File.WriteAllText(FileText);
I want to update this answer to say that this is not really the most efficient way to write all text. You should only use this code if you need something quick and dirty.
I was a young programmer when I answered this question, and back then I thought I was some kind of genius for coming up with this answer.
The File.Create method creates the file and opens a FileStream on the file. So your file is already open. You don't really need the file.Create method at all:
string filePath = #"c:\somefilename.txt";
using (StreamWriter sw = new StreamWriter(filePath, true))
{
//write to the file
}
The boolean in the StreamWriter constructor will cause the contents to be appended if the file exists.
When creating a text file you can use the following code:
System.IO.File.WriteAllText("c:\test.txt", "all of your content here");
Using the code from your comment. The file(stream) you created must be closed. File.Create return the filestream to the just created file.:
string filePath = "filepath here";
if (!System.IO.File.Exists(filePath))
{
System.IO.FileStream f = System.IO.File.Create(filePath);
f.Close();
}
using (System.IO.StreamWriter sw = System.IO.File.AppendText(filePath))
{
//write my text
}
FileStream fs= File.Create(ConfigurationManager.AppSettings["file"]);
fs.Close();
File.Create returns a FileStream. You need to close that when you have written to the file:
using (FileStream fs = File.Create(path, 1024))
{
Byte[] info = new UTF8Encoding(true).GetBytes("This is some text in the file.");
// Add some information to the file.
fs.Write(info, 0, info.Length);
}
You can use using for automatically closing the file.
I updated your question with the code snippet. After proper indenting, it is immediately clear what the problem is: you use File.Create() but don't close the FileStream that it returns.
Doing it that way is unnecessary, StreamWriter already allows appending to an existing file and creating a new file if it doesn't yet exist. Like this:
string filePath = string.Format(#"{0}\M{1}.dat", ConfigurationManager.AppSettings["DirectoryPath"], costCentre);
using (StreamWriter sw = new StreamWriter(filePath, true)) {
//write my text
}
Which uses this StreamWriter constructor.
I know this is an old question, but I just want to throw this out there that you can still use File.Create("filename")", just add .Dispose() to it.
File.Create("filename").Dispose();
This way it creates and closes the file for the next process to use it.
This question has already been answered, but here is a real world solution that
checks if the directory exists and adds a number to the end if the text file
exists. I use this for creating daily log files on a Windows service I wrote. I
hope this helps someone.
// How to create a log file with a sortable date and add numbering to it if it already exists.
public void CreateLogFile()
{
// filePath usually comes from the App.config file. I've written the value explicitly here for demo purposes.
var filePath = "C:\\Logs";
// Append a backslash if one is not present at the end of the file path.
if (!filePath.EndsWith("\\"))
{
filePath += "\\";
}
// Create the path if it doesn't exist.
if (!Directory.Exists(filePath))
{
Directory.CreateDirectory(filePath);
}
// Create the file name with a calendar sortable date on the end.
var now = DateTime.Now;
filePath += string.Format("Daily Log [{0}-{1}-{2}].txt", now.Year, now.Month, now.Day);
// Check if the file that is about to be created already exists. If so, append a number to the end.
if (File.Exists(filePath))
{
var counter = 1;
filePath = filePath.Replace(".txt", " (" + counter + ").txt");
while (File.Exists(filePath))
{
filePath = filePath.Replace("(" + counter + ").txt", "(" + (counter + 1) + ").txt");
counter++;
}
}
// Note that after the file is created, the file stream is still open. It needs to be closed
// once it is created if other methods need to access it.
using (var file = File.Create(filePath))
{
file.Close();
}
}
I think I know the reason for this exception. You might be running this code snippet in multiple threads.
you can just use using keyword around File.Create(path) to finalize the process
using(File.Create(path));
Try this: It works in any case, if the file doesn't exists, it will create it and then write to it. And if already exists, no problem it will open and write to it :
using (FileStream fs= new FileStream(#"File.txt",FileMode.Create,FileAccess.ReadWrite))
{
fs.close();
}
using (StreamWriter sw = new StreamWriter(#"File.txt"))
{
sw.WriteLine("bla bla bla");
sw.Close();
}
How can I clear the content of a text file using C# ?
File.WriteAllText(path, String.Empty);
Alternatively,
File.Create(path).Close();
Just open the file with the FileMode.Truncate flag, then close it:
using (var fs = new FileStream(#"C:\path\to\file", FileMode.Truncate))
{
}
using (FileStream fs = File.Create(path))
{
}
Will create or overwrite a file.
You can clear contents of a file just like writing contents in the file but replacing the texts with ""
File.WriteAllText(#"FilePath", "");
Another short version:
System.IO.File.WriteAllBytes(path, new byte[0]);
Simply write to file string.Empty, when append is set to false in StreamWriter. I think this one is easiest to understand for beginner.
private void ClearFile()
{
if (!File.Exists("TextFile.txt"))
File.Create("TextFile.txt");
TextWriter tw = new StreamWriter("TextFile.txt", false);
tw.Write(string.Empty);
tw.Close();
}
You can use always stream writer.It will erase old data and append new one each time.
using (StreamWriter sw = new StreamWriter(filePath))
{
getNumberOfControls(frm1,sw);
}