I am trying to write a program to me should be a lot easier than it is proving.
I have a form with text boxes that asks the user to enter their details e.g. Name, Address etc.. What I am trying to achieve is to save the data from the text boxes into a .txt file when the user hits the save button.
I am able to create the file but the data will not save into the file.
I have posted my code below, and any help you may have will be greatly appreciated.
private void btnSave_Click(object sender, EventArgs e)
{
string file_name = "e:\\test1.txt";
System.IO.StreamWriter objWriter;
objWriter = new System.IO.StreamWriter(file_name, true);
objWriter.Write(txtName.Text);
objWriter.Write(txtAddress.Text);
objWriter.Write(txtEmail.Text);
objWriter.Write(txtPhone.Text);
MessageBox.Show("Details have been saved");
}
It would be more practical to use using at the beginning of the code line where StreamWriter is present. This is to ensure data are Disposed, you'll need this to unlock the data from the stream.
When writing data:
using (StreamWriter objWriter = new StreamWriter("test1.txt"))
{
objWriter.Write(txtName.Text);
objWriter.Write(txtAddress.Text);
objWriter.Write(txtEmail.Text);
objWriter.Write(txtPhone.Text);
MessageBox.Show("Details have been saved");
}
When reading saved data, let's use a listbox just to have an example:
foreach (var line in File.ReadAllLines("test1.txt"))
{
listBox1.Items.Add(line);
}
Hope this helps!
It is a good practice to wrap local variables implementing IDisposable into the using statement:
using (StreamWriter objWriter = new StreamWriter(file_name, true))
{
objWriter.Write(txtName.Text);
objWriter.Write(txtAddress.Text);
objWriter.Write(txtEmail.Text);
objWriter.Write(txtPhone.Text);
}
This also has a positive side effect: the stream is flushed and closed right after execution of the using statement.
Suggestion: Consider using WriteLine instead of Write, because probably you need a delimiter between string values.
Call StreamWriter.Flush method after you done:
objWriter.Flush();
Clears all buffers for the current writer and causes any buffered data to be written to the underlying stream.
You could also do this using File.WriteAllText method:
var line = string.Join(" ", txtName.Text, txtAddress.Text, txtEmail.Text,txtPhone.Text);
File.WriteAllText(file_name, line);
Related
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 am trying to export the strings in a nested list to a txt or csv file of the users choice and everything seems to be working but when I actually go to check the file after I have exported it the file is absolutely blank. I went and did it on a separate test program to mock my problem and it worked on that program but when I moved the code over it would still not export anything.
This is just my initialized nested list in case its needed.
List<List<string>> aQuestion = new List<List<string>>();
This is the problem area for the code.
static void writeCSV(List<List<string>> aQuestion, List<char> aAnswer)
{
StreamWriter fOut = null;
string fileName = "";
//export questions
//determine if the file can be found
try
{
Console.Write("Enter the file path for where you would like to export the exam to: ");
fileName = Console.ReadLine();
if (!File.Exists(fileName))
{
throw new FileNotFoundException();
}
}
catch (FileNotFoundException)
{
Console.WriteLine("File {0} cannot be found", fileName);
}
//writes to the file
try
{
fOut = new StreamWriter(fileName, false);
//accesses the nested lists
foreach (var line in aQuestion)
{
foreach (var value in line)
{
fOut.WriteLine(string.Join("\n", value));
}
}
Console.WriteLine("File {0} successfully written", fileName);
}
catch (IOException ioe)
{
Console.WriteLine("File {0} cannot be written {1}", fileName, ioe.Message);
}
So if any of you guys can help me with this problem that would be great because it seems like such a small problem but I can't figure it out for the life of me.
It may happen that the buffer was not flushed to the disk. You should dispose the stream writer and it will push everything out to disk:
using (StreamWriter writer = new StreamWriter(fileName, false)) // <-- this is the change
{
//accesses the nested lists
foreach (var line in aQuestion)
{
foreach (var value in line)
{
writer.WriteLine(string.Join("\n", value));
}
}
}
On a more elaborate level, streams that may cause performance loss are normally buffered. File streams are definitely buffered, because it would be very inefficient to push each separate piece of data to the IO immediately.
When you're working with file streams, you can flush their content explicitly using the StreamWriter.Flush() method - that is useful if you want to debug code and wish to see how far it has gone writing the data.
However, you normally do not flush the stream yourself but just let its internal mechanisms choose the best moment to do that. Instead, you make sure to dispose the stream object, and that will force buffer to be flushed before closing the stream.
Use this simple method instead, it is much easier and it will take care of creating and disposing StreamWriter.
File.WriteAllLines(PathToYourFile,aQuestion.SelectMany(x=>x));
More reference on File.WriteAllLines Here
Also, in your code your not disposing StreamWrite. Enclose it in a Using block. Like this..
using(var writer = new StreamWriter(PathToYourFile,false)
{
//Your code here
}
I am writing a program where I have 2 listboxes with the same data but the one listbox items are update with the student name and their TOTAL score and the other with the student name and each individual judge score next to the student name. Everything is going good so far but now I am stuck... I have two methods Save() and SaveAs() where Save() automatically writes data to "FormData.bin" and SaveAs() lets the user enter their own file name.
Is it possible to re-write the Save() method so that when I click save it saves the current data to the file that is open like in MS Word when you are typing in document and just click save to add new typed data to current file. Here is my Save() method I wrote.
public void SaveEntry()
{
int itemsCount = Math.Min(lstbxStudents.Items.Count, lstbxStudentScore.Items.Count);
saveFileDialog1.InitialDirectory = Application.StartupPath;
saveFileDialog1.FileName = "FormData.bin";
{
try
{
using (FileStream fs = new FileStream(saveFileDialog1.FileName, FileMode.Create))
using (BinaryWriter Save = new BinaryWriter(fs))
{
Save.Write(cmbbxAge.Text);
Save.Write(cmbbxBelt.Text);
Save.Write(cmbbxCategorie.Text);
Save.Write(cmbbxGender.Text);
Save.Write(cmbbxGup.Text);
Save.Write(txtJudge1.Text);
Save.Write(txtJudge2.Text);
Save.Write(txtJudge3.Text);
Save.Write(txtJudge4.Text);
Save.Write(txtJudge5.Text);
Save.Write(txtOperator.Text);
Save.Write(txtPos1.Text);
Save.Write(txtPos2.Text);
Save.Write(txtPos3.Text);
Save.Write(txtPos4.Text);
Save.Write(txtPos5.Text);
for (int i = 0; i < itemsCount; i++)
{
Save.Write(lstbxStudents.Items[i].ToString());
Save.Write(lstbxStudentScore.Items[i].ToString());
}
Save.Close();
fs.Close();
}
}
catch (Exception error)
{
MessageBox.Show(error.Message, "CTSD Forms");
}
}
}
Thank you in advance
Here is image of Form
Window Form
If I understood correctly what you are trying to achieve is to append text rather than overwrite it. Take a look upon the StreamWriter class that also allows to specify if you want to append the data or not when constructing the instance. It also allows to create/append to the file directly, without the need of a Stream.
Also, consider using proper names for variables:
Save is an action, not an object. writer would be better.
By using Write in the way you showed in your code, you will end with all the texts appended with no separators. You should consider using WriteLine functions.
[edit upon clarifications]
SaveEntry should take a parameter to specify if save is done as SaveAs or Save. First save should always be a SaveAs. Also filename should be saved in the context (your form class, but it is better to have a "view model")
private String _currentFileName;
public void SaveEntry(bool saveAs)
{
if (saveAs || String.IsNullOrEmpty(_currentFileName))
{
saveFileDialog1.InitialDirectory = Application.StartupPath;
saveFileDialog1.FileName = "FormData.bin";
var result = saveFileDialog1.ShowDialog();
// TODO: handle user cancellation
_currentFileName = saveFileDialog1.FileName;
}
using (var writer = new StreamWriter(_currentFileName))
{
// TODO: do stuff with your writer
}
}
Hi all i write a code to write my last row of datagrid view to a file as follows
private void Save_Click(object sender, EventArgs e)
{
if (dataGridView1.Rows.Count > 0)
{
List<string> lstContent = new List<string>();
foreach (DataGridViewRow row in dataGridView1.Rows)
{
if ((string)row.Cells[0].Value == "FileControl")
{
lstContent.Add((string)row.Cells[1].Value);
string mydata = string.Join(",", lstContent.ToArray());
using (StreamWriter sw = new StreamWriter(Append.FileName, true))
{
sw.WriteLine();
sw.Write(mydata);
}
}
}
}
}
But if i click multiple times on save this is writing that line multiple times what i need is if already that line exists in the file i have to replace that line with new line. Any help please
Your StreamWriter is explicitly using the file with append = true. Change the second parameter of the constructor to false if you want to overwrite the file each time. Docs are here. Quote:
append
Type: System.Boolean
Determines
whether data is to be appended to the
file. If the file exists and append is
false, the file is overwritten. If the
file exists and append is true, the
data is appended to the file.
Otherwise, a new file is created.
Revised code:
using (StreamWriter sw = new StreamWriter(Append.FileName, false))
{
sw.WriteLine();
sw.Write(mydata);
}
Replacing a given line in your file rather than just overwriting the whole file is a lot more difficult - this code is not going to get it done. StreamWriter is not great for this, you need random access and the ability to replace one data segment (line) by a different data segment of different length, which is an expensive operation on disk.
You might want to keep the files in memory as a container of Strings and do your required line replacement within the container, then write out the file to disk using File.WriteAllLines - that's if the file is not too big.
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();
}