I'm new to C# and I'm having a bit of an issue when saving to a new file. My program has two options for saving: save & save as.
I was getting a sharing violation error when saving, but I fixed that by closing the previous filestream. However, I still cant figure out why my save as code is giving me a sharing violation error.
Here's the code:
// get a file stream from the file chooser
FileStream file = File.OpenWrite(saveFc.Filename);
// check to see if the file is Ok
bool fileOk = file.CanWrite;
if (fileOk == true)
{
// get the filename
string filename = file.Name;
// store the filename for later use
UtilityClass.filename = filename;
// get the text from textview1
string text = textview1.Buffer.Text;
// get a StreamWriter
StreamWriter writer = File.CreateText(filename);
// write to the file
writer.Write(text);
// close/save the file
writer.Close();
file.Close();
}
}
// close the file c
If you could help me figure it out that would be much appreciated. Thanks!
You're opening the same file twice:
FileStream file = File.OpenWrite(saveFc.Filename);
And:
string filename = file.Name;
StreamWriter writer = File.CreateText(filename);
Your code could probably be simplified to:
using (var writer = File.CreateText(saveFc.Filename))
{
// store the filename for later use
UtilityClass.filename = saveFc.Filename;
// get the text from textview1
string text = textview1.Buffer.Text;
// write the text
writer.Write(text);
}
If you open the file with CreateText/OpenWrite it will always be writeable (or an exception will be thrown). The using block will automatically close the writer when it exits.
Related
I am creating a text file and after that I am trying to write some text in that file.but when writing text,it's generating exception that process cannot access file because it's being used by another process. Kindly someone help :( Thanks in advance.
Here is my code
dt_Loc = loc1_ctab.GetEmpLocInfo(Session["empcd"].ToString());
string str = DateTime.Now.ToString("dd-mmm-yyyy");
str = dt_Loc.Rows[0]["loc1_abrv"].ToString() + "-" + str;
string path = FilesPath.Path_SaveFile + str + ".txt";
if (!File.Exists(path))
{
File.Create(path);
TextWriter tw = new StreamWriter(path);
tw.WriteLine(txt_comments.Text);
tw.Close();
}
Remove the File.Create since it opens a FileStream for the file.This results in the file being open and hence you get the exception that the file is being used by another process.
if (!File.Exists(path))
{
using(StreamWriter sw = new StreamWriter(path))
{
sw.WriteLine(txt_comments.Text);
}
}
Your code giving such error because, the method Create Creates or overwrites a file in the specified path. which will return A FileStream that provides read/write access to the file specified in path. So at the time of executing the writemethod, the file is being used by the returned FS. you can use this in the following way:
using (FileStream fs = File.Create(path))
{
Byte[] info = new UTF8Encoding(true).GetBytes(txt_comments.Text);
// Add some information to the file.
fs.Write(info, 0, info.Length);
}
You can Make it simple by using File.WriteAllText which will Creates a new file, write the contents to the file, and then closes the file. If the target file already exists, it is overwritten.
string path =FilesPath.Path_SaveFile + str + ".txt";;
if (!File.Exists(path))
{
File.WriteAllText(path, txt_comments.Text);
}
I'm getting the error The process cannot access the file 'C:\Users\Ryan\Desktop\New folder\POSData.txt' because it is being used by another process. when I try to create a file and then write to it. What process is using the file?? I checked for a file.close to call after I create the file, but it doesn't exist. How do I get past this? Thanks!
Heres my code:
MessageBox.Show("Please select a folder to save your database to.");
this.folderBrowserDialog1.RootFolder = System.Environment.SpecialFolder.Desktop;
DialogResult result = this.folderBrowserDialog1.ShowDialog();
if (result == DialogResult.OK)
{
databasePath = folderBrowserDialog1.SelectedPath;
if (!File.Exists(databasePath + "\\POSData.txt"))
{
File.Create(databasePath + "\\POSData.txt");
}
using (StreamWriter w = new StreamWriter(databasePath + "\\POSData.txt", false))
{
w.WriteLine(stockCount);
}
}
Edit: Only happens when creating the file. If it already exists, no error occurs.
Actually, don't even bother using File.Create. The reason you're getting that error is because File.Create is opening up a stream on that text file.
string filePath = "databasePath + "\\POSData.txt"";
using (StreamWriter sw = new StreamWriter(filePath, true))
{
//write to the file
}
You are keeping the file open when you call File.Create (i.e. you never close the file).
StreamWriter will create the file for you if it doesn't exist, so I wouldn't bother checking yourself. You could just remove the code that checks whether it exists and creates it if it doesn't.
if (result == DialogResult.OK)
{
databasePath = folderBrowserDialog1.SelectedPath;
using (StreamWriter w = new StreamWriter(databasePath + "\\POSData.txt", false))
{
w.WriteLine(stockCount);
}
}
Note that if the file doesn't exist, the second bool parameter in the StreamWriter constructor is ignored.
File.Create also opens the file for reading/writing. As such, you're leaving an open FileStream when you File.Create.
Assuming that overwriting is OK, then you probably want to do something like this:
using (var fs = File.Create(databasePath + "\\POSData.txt"))
using (StreamWriter w = new StreamWriter(fs))
{
w.WriteLine(stockCount);
}
given that File.Create:
Creates or overwrites a file in the specified path.
The File.Create returns a FileStream object that might need to be closed.
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.
using (FileStream fs = File.Create(databasePath + "\\POSData.txt"))
{
fs.Write(uniEncoding.GetBytes(stockCount), 0, uniEncoding.GetByteCount(stockCount));
}
I used this and it worked
`File.AppendAllText(fileName,"");`
This creates a new file, writes nothing to it, then closes it for you.
I need to read the string in the text file which contains the default image name and then close the ReadLine(). The way I am trying to close it now is no good and the process is not terminated and
causes "file being used by another process" errors elsewhere in the program, when the text file in question needs to be overwritten.
DirectoryInfo sourceDir = new DirectoryInfo(System.Web.HttpContext.Current.Request.MapPath("~/Content/ProductImages/" + Model.Products[i].ProductID.ToString() + "/thumbs/"));
FileInfo[] defaultImage = sourceDir.GetFiles("defaultImage.txt");
string defimg = defaultImage[0].OpenText().ReadLine();
defaultImage[0].OpenText().Close();
If you want to read the first line:
using (var reader = defaultImage[0].OpenText())
{
string defimg = reader.ReadLine();
}
or if you want to read the entire file contents into a string:
string defimg = File.ReadAllText(defaultImage[0].FullName);
You close the stream that you opened, instead of opening another stream and close that instead...
var stream = defaultImage[0].OpenText();
string defimg = stream.ReadLine();
stream.Close();
Or using a using block:
string defimg;
using (stream = defaultImage[0].OpenText()) {
defimg = stream.ReadLine();
}
defaultImage[0].OpenText() Everytime creates a new StreamReader. So in your case, you are not closing the one which you have opened.
Below should work.
var sr = defaultImage[0].OpenText();
string str = x.ReadLine();
sr.Close();
I am trying to make a text file in memory, add some lines to it and at the end save the file in a text file. I can handle the savedialog part but I dont know how to get the text file from memory. Any help and tips will be appriciated.
What I am doing so far is:
//Initialize in memory text writer
MemoryStream ms = new MemoryStream();
TextWriter tw = new StreamWriter(ms);
tw.WriteLine("HELLO WORLD!");
tw.WriteLine("I WANT TO SAVE THIS FILE AS A .TXT FILE!);
please note
I will call tw.WriteLine() add more lines in different places so I want to save this at end of program (so this shouldent be wrapped between something like using{} )
UPDATE
StringBuilder seems to be a more reliable option for doing this! I get strange cut-outs in my text file when I do it using MemoryStream.
Thanks.
I think your best option here would be to write to a StringBuilder, and when done, File.WriteAllText. If the contents are large, you might consider writing directly to the file in the first place (via File.CreateText(path)), but for small-to-medium files this should be fine.
var sb = new StringBuilder();
sb.AppendLine("HELLO WORLD!");
sb.AppendLine("I WANT TO SAVE THIS FILE AS A .TXT FILE!");
File.WriteAllText(path, sb.ToString());
Or, something nigh-on the same as #Marc's answer, but different enough that I think it's worth putting out there as a valid solution:
using (var writer = new StringWriter())
{
writer.WriteLine("HELLO WORLD!");
writer.WriteLine("I WANT TO SAVE THIS FILE AS A .TXT FILE!");
File.WriteAllLines(path, writer.GetStringBuilder().ToString());
}
Where path is a string representing a valid file system entry path, predefined by you somewhere in the application.
Assume your SaveFileDialog name is "dialog"
File.WriteAllBytes(dialog.FileName, Encoding.UTF8.GetBytes("Your string"));
or
var text = "Your string";
text += "some other text";
File.WriteAllText(dialog.FileName, text);
also in your own solution you can do this :
MemoryStream ms = new MemoryStream();
TextWriter tw = new StreamWriter(ms);
tw.WriteLine("HELLO WORLD!");
tw.WriteLine("I WANT TO SAVE THIS FILE AS A .TXT FILE!);
// just add this
File.WriteAllBytes(dialog.FileName, ms.GetBuffer());
Something like this.
Microsoft.Win32.SaveFileDialog dlg = new Microsoft.Win32.SaveFileDialog();
dlg.FileName = "Document"; // Default file name
dlg.DefaultExt = ".text"; // Default file extension
dlg.Filter = "Text documents (.txt)|*.txt"; // Filter files by extension
// Show save file dialog box
Nullable<bool> result = dlg.ShowDialog();
// Process save file dialog box results
if (result == true)
{
// Save document
using (FileStream file = File.CreateText(dlg.FileName)
{
ms.WriteTo(file)
}
}
I haven't worried about whether the file already exists but this should get you close.
You might need a ms.Seek(SeekOrgin.Begin, 0) too.
Another way of appending text to the end of a file could be:
if (saveFileDialog.ShowDialog() == DialogResult.OK) {
using (var writer = new StreamWriter(saveFileDialog.Filename, true)) {
writer.WriteLine(text);
}
}
supposing that text is the string you need to save into your file.
If you want to append new lines to that string in an easy way, you can do:
var sb = new StringBuilder();
sb.AppendLine("Line 1");
sb.AppendLine("Line 2");
and the resulting string will be sb.ToString()
If you already have a Stream object (in your example, a MemoryStream), you can do the same but replace the line:
using (var writer = new StreamWriter(saveFileDialog.Filename, true)) {
by
using (var writer = new StreamWriter(memoryStream)) {
Edit:
About wrapping the statements inside using:
Take in count that this is not a problem at all. In my first example, all you will have to do is to keep that StringBuilder object, and keep adding lines to it. Once you have what you want, just write the data into a text file.
If you are planning to write more than once to the text file, just clear the StringBuilder everytime you write, in order to not get duplicated data.
How would I open a file, perform some regex on the file, and then save the file?
I know I can open a file, read line by line, but how would I update the actual contents of a file and then save the file?
The following approach would work regardless of file size, and will also not corrupt the original file in anyway if the operation would fail before it is complete:
string inputFile = Path.Combine(Environment.GetFolderPath(
Environment.SpecialFolder.MyDocuments), "temp.txt");
string outputFile = Path.Combine(Environment.GetFolderPath(
Environment.SpecialFolder.MyDocuments), "temp2.txt");
using (StreamReader input = File.OpenText(inputFile))
using (Stream output = File.OpenWrite(outputFile))
using (StreamWriter writer = new StreamWriter(output))
{
while (!input.EndOfStream)
{
// read line
string line = input.ReadLine();
// process line in some way
// write the file to temp file
writer.WriteLine(line);
}
}
File.Delete(inputFile); // delete original file
File.Move(outputFile, inputFile); // rename temp file to original file name
string[] lines = File.ReadAllLines(path);
string[] transformedLines = lines.Select(s => Transform(s)).ToArray();
File.WriteAllLines(path, transformedLines);
Here, for example, Transform is
public static string Transform(string s) {
return s.Substring(0, 1) + Char.ToUpper(s[1]) + s.Substring(2);
}
Open the file for read. Read all the contents of the file into memory. Close the file. Open the file for write. Write all contents to the file. Close the file.
Alternatively, if the file is very large:
Open fileA for read. Open a new file (fileB) for write. Process each line of fileA and save to fileB. Close fileA. Close fileB. Delete fileA. Rename fileB to fileA.
Close the file after you finish reading it
Reopen the file for write
Write back the new contents