I have a textbox where a user can input their email, what I want to do is make it so that when they click a submit button. That email will be saved into a text file ( on my server ) called emails.txt
I managed to get this working using System.IO and then using the File.WriteAll method. However I want to make it so that it will add the email to the list ( on a new line ) rather then just overwriting whats already in there.
I've seen people mention using Append, but I can't quite grasp how to get it working.
This is my current code (that overwrites instead of appending).
public partial class _Default : Page
{
private string path = null;
protected void Page_Load(object sender, EventArgs e)
{
path = Server.MapPath("~/emails.txt");
}
protected void emailButton_Click(object sender, EventArgs e)
{
File.WriteAllText(path, emailTextBox.Text.Trim());
confirmEmailLabel.Text = "Thank you for subscribing";
}
}
You can use StreamWriter to get working with text file. The WriteLine method in true mode append your email in new line each time....
using (StreamWriter writer = new StreamWriter("email.txt", true)) //// true to append data to the file
{
writer.WriteLine("your_data");
}
From the official MSDN documentation:
using (StreamWriter w = File.AppendText("log.txt"))
{
MyWriteFunction("Test1", w);
MyWriteFunction("Test2", w);
}
Use StreamWriter in Append mode. Write your data with WriteLine(data).
using (StreamWriter writer = new StreamWriter("emails.txt", true))
{
writer.WriteLine(email);
}
Seems like a very easy question with a very easy answer: Open existing file, append a single line
If you post the current code, we can modify that to append instead of overwrite.
Related
There are a lot of different ways to read and write files (text files, not binary) in C#.
I just need something that is easy and uses the least amount of code, because I am going to be working with files a lot in my project. I only need something for string since all I need is to read and write strings.
Use File.ReadAllText and File.WriteAllText.
MSDN example excerpt:
// Create a file to write to.
string createText = "Hello and Welcome" + Environment.NewLine;
File.WriteAllText(path, createText);
...
// Open the file to read from.
string readText = File.ReadAllText(path);
In addition to File.ReadAllText, File.ReadAllLines, and File.WriteAllText (and similar helpers from File class) shown in another answer you can use StreamWriter/StreamReader classes.
Writing a text file:
using(StreamWriter writetext = new StreamWriter("write.txt"))
{
writetext.WriteLine("writing in text file");
}
Reading a text file:
using(StreamReader readtext = new StreamReader("readme.txt"))
{
string readText = readtext.ReadLine();
}
Notes:
You can use readtext.Dispose() instead of using, but it will not close file/reader/writer in case of exceptions
Be aware that relative path is relative to current working directory. You may want to use/construct absolute path.
Missing using/Close is very common reason of "why data is not written to file".
FileStream fs = new FileStream(txtSourcePath.Text,FileMode.Open, FileAccess.Read);
using(StreamReader sr = new StreamReader(fs))
{
using (StreamWriter sw = new StreamWriter(Destination))
{
sw.Writeline("Your text");
}
}
The easiest way to read from a file and write to a file:
//Read from a file
string something = File.ReadAllText("C:\\Rfile.txt");
//Write to a file
using (StreamWriter writer = new StreamWriter("Wfile.txt"))
{
writer.WriteLine(something);
}
using (var file = File.Create("pricequote.txt"))
{
...........
}
using (var file = File.OpenRead("pricequote.txt"))
{
..........
}
Simple, easy and also disposes/cleans up the object once you are done with it.
#AlexeiLevenkov pointed me at another "easiest way" namely the extension method. It takes just a little coding, then provides the absolute easiest way to read/write, plus it offers the flexibility to create variations according to your personal needs. Here is a complete example:
This defines the extension method on the string type. Note that the only thing that really matters is the function argument with extra keyword this, that makes it refer to the object that the method is attached to. The class name does not matter; the class and method must be declared static.
using System.IO;//File, Directory, Path
namespace Lib
{
/// <summary>
/// Handy string methods
/// </summary>
public static class Strings
{
/// <summary>
/// Extension method to write the string Str to a file
/// </summary>
/// <param name="Str"></param>
/// <param name="Filename"></param>
public static void WriteToFile(this string Str, string Filename)
{
File.WriteAllText(Filename, Str);
return;
}
// of course you could add other useful string methods...
}//end class
}//end ns
This is how to use the string extension method, note that it refers automagically to the class Strings:
using Lib;//(extension) method(s) for string
namespace ConsoleApp_Sandbox
{
class Program
{
static void Main(string[] args)
{
"Hello World!".WriteToFile(#"c:\temp\helloworld.txt");
return;
}
}//end class
}//end ns
I would never have found this myself, but it works great, so I wanted to share this. Have fun!
These are the best and most commonly used methods for writing to and reading from files:
using System.IO;
File.AppendAllText(sFilePathAndName, sTextToWrite);//add text to existing file
File.WriteAllText(sFilePathAndName, sTextToWrite);//will overwrite the text in the existing file. If the file doesn't exist, it will create it.
File.ReadAllText(sFilePathAndName);
The old way, which I was taught in college was to use stream reader/stream writer, but the File I/O methods are less clunky and require fewer lines of code. You can type in "File." in your IDE (make sure you include the System.IO import statement) and see all the methods available. Below are example methods for reading/writing strings to/from text files (.txt.) using a Windows Forms App.
Append text to an existing file:
private void AppendTextToExistingFile_Click(object sender, EventArgs e)
{
string sTextToAppend = txtMainUserInput.Text;
//first, check to make sure that the user entered something in the text box.
if (sTextToAppend == "" || sTextToAppend == null)
{MessageBox.Show("You did not enter any text. Please try again");}
else
{
string sFilePathAndName = getFileNameFromUser();// opens the file dailog; user selects a file (.txt filter) and the method returns a path\filename.txt as string.
if (sFilePathAndName == "" || sFilePathAndName == null)
{
//MessageBox.Show("You cancalled"); //DO NOTHING
}
else
{
sTextToAppend = ("\r\n" + sTextToAppend);//create a new line for the new text
File.AppendAllText(sFilePathAndName, sTextToAppend);
string sFileNameOnly = sFilePathAndName.Substring(sFilePathAndName.LastIndexOf('\\') + 1);
MessageBox.Show("Your new text has been appended to " + sFileNameOnly);
}//end nested if/else
}//end if/else
}//end method AppendTextToExistingFile_Click
Get file name from the user via file explorer/open file dialog (you will need this to select existing files).
private string getFileNameFromUser()//returns file path\name
{
string sFileNameAndPath = "";
OpenFileDialog fd = new OpenFileDialog();
fd.Title = "Select file";
fd.Filter = "TXT files|*.txt";
fd.InitialDirectory = Environment.CurrentDirectory;
if (fd.ShowDialog() == DialogResult.OK)
{
sFileNameAndPath = (fd.FileName.ToString());
}
return sFileNameAndPath;
}//end method getFileNameFromUser
Get text from an existing file:
private void btnGetTextFromExistingFile_Click(object sender, EventArgs e)
{
string sFileNameAndPath = getFileNameFromUser();
txtMainUserInput.Text = File.ReadAllText(sFileNameAndPath); //display the text
}
Or, if you are really about lines:
System.IO.File also contains a static method WriteAllLines, so you could do:
IList<string> myLines = new List<string>()
{
"line1",
"line2",
"line3",
};
File.WriteAllLines("./foo", myLines);
It's good when reading to use the OpenFileDialog control to browse to any file you want to read. Find the code below:
Don't forget to add the following using statement to read files: using System.IO;
private void button1_Click(object sender, EventArgs e)
{
if (openFileDialog1.ShowDialog() == DialogResult.OK)
{
textBox1.Text = File.ReadAllText(openFileDialog1.FileName);
}
}
To write files you can use the method File.WriteAllText.
class Program
{
public static void Main()
{
//To write in a txt file
File.WriteAllText("C:\\Users\\HP\\Desktop\\c#file.txt", "Hello and Welcome");
//To Read from a txt file & print on console
string copyTxt = File.ReadAllText("C:\\Users\\HP\\Desktop\\c#file.txt");
Console.Out.WriteLine("{0}",copyTxt);
}
}
private void Form1_Load(object sender, EventArgs e)
{
//Write a file
string text = "The text inside the file.";
System.IO.File.WriteAllText("file_name.txt", text);
//Read a file
string read = System.IO.File.ReadAllText("file_name.txt");
MessageBox.Show(read); //Display text in the file
}
Reading from file
string filePath = #"YOUR PATH";
List<string> lines = File.ReadAllLines(filePath).ToList();
Writing to file
List<string> lines = new List<string>();
string a = "Something to be written"
lines.Add(a);
File.WriteAllLines(filePath, lines);
Simply:
String inputText = "Hello World!";
File.WriteAllText("yourfile.ext",inputText); //writing
var outputText = File.ReadAllText("yourfile.ext"); //reading
You're looking for the File, StreamWriter, and StreamReader classes.
I have a installer class in my winform application by using which i am creating setup of my application.Now i want the values entered into setup textboxes to get retrieved into installer class and write into text file using custom action .Here is the parameter i am trying to send using custom action of Setup project..
/targetdir="[TARGETDIR]\"/Param1="[EDITA1]"/Param2="[EDITA2]"/Param3="[EDITA3]"
And here is the way i am trying to retrieve and write into newly created text file which is not happening..
public override void Install(System.Collections.IDictionary stateSaver)
{
base.Install(stateSaver);
string targetDirectory = Context.Parameters["targetdir"];
string param1 = Context.Parameters["Param1"];
string param2 = Context.Parameters["Param2"];
string param3 = Context.Parameters["Param3"];
try
{
File.Create("D:\\Yourfile.txt");
FileStream fs1 = new FileStream("D:\\Yourfile.txt", FileMode.OpenOrCreate, FileAccess.Write);
StreamWriter writer = new StreamWriter(fs1);
writer.Write("Hello", writer.NewLine);
writer.Write(param1, writer.NewLine);
writer.Write(param2, writer.NewLine);
writer.Write(param3, writer.NewLine);
writer.Close();
}
catch {
}
}
I am not able to get even Hello in my textfile.Please tell me where i am going wrong..
Thanks..
You're creating a file and then trying to access it , which generates an IOException, which you happily swallow with the empty catch.
You can simply comment out the following line File.Create("D:\\Yourfile.txt");, and then it'll work for you.
Do note that you're writting lines, and relaying on the writer.NewLine. I would probably use the following if this is what you want:
writer.WriteLine("hello");
Other than that, You can also just write to a string or an array of strings, and do :
var first_ten = read_all_lines.Take(10);
var out_path = "D:\\Yourfile.txt";
System.IO.File.WriteAllLines(out_path, first_ten);
I'm trying to take the data from two text boxes, and writing it to file without replacing the current stuff already there when a button is pressed. This is what I have so far:
private void button1_Click_1(object sender, EventArgs e)
{
using (StreamWriter sw1 = new StreamWriter("DataNames.txt"))
{
sw1.WriteLine(textBox1.Text);
}
using (StreamWriter sw2 = new StreamWriter("DataNumbers.txt"))
{
sw2.WriteLine(textBox2.Text);
}
}
Right now it takes the input, and replaces whatever is currently in the files so then there is only one line, instead of just adding it to the list. Thanks for the help.
//using (StreamWriter sw1 = new StreamWriter("DataNames.txt"))
//{
// sw1.WriteLine(textBox1.Text);
//}
System.IO.File.AppendAllText("DataNames.txt", textBox1.Text);
Use StreamWriter Constructor (String, Boolean) constructor and pass true for append.
true to append data to the file; false to overwrite the file. If the specified file does not exist, this parameter has no effect, and
the constructor creates a new file.
In your code pass true like:
using (StreamWriter sw1 = new StreamWriter("DataNames.txt",true))
Try this
using (StreamWriter sw2 = new StreamWriter("DataNumbers.txt", true))
{
sw2.WriteLine(textBox2.Text);
}
Second argument true tells that file needs to be appended instead of overwriting. StreamWriter(String, Boolean)
Switch the
new StreamWriter("DataNumbers.txt")
to
File.CreateText("DataNames.txt")
You can find more info at:
http://msdn.microsoft.com/en-us/library/system.io.file.appendtext.aspx
You are making two separate instance of stream writer, and they are both attempting to write to the same file, so they are competing with each other - that's why you are seeing the overwriting.
If you want to add text to the end of a file, the best way to do so is probably File.AppendAllText: http://msdn.microsoft.com/en-us/library/ms143356.aspx
private void button1_Click_1(object sender, EventArgs e)
{
System.IO.File.AppendAllText("DataNames.txt", textBox1.Text + textBox2.Text);
}
AppendAllText is quite useful if you are doing small, relatively infrequent appends as you can just send strings into it without thinking as opposed to making sure you are using your stream writer.
I am making simple tool for manipulating images in a database. I want to show the output result in a txt file and because the outcome may be different each time, I want the file to be rewritten with the fresh data every time the data is executed.
Also I want (if possible) to use some default location where the txt file will be created even though I have an App.Config file and that's also an option.
The problem I am having is with this code:
string Resultfile =
System.Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments) +
"\\PictureStatus.txt";
FileStream strm = new FileStream(Resultfile , FileMode.Create);
TextWriter tw = new StreamWriter(strm);
This populates the PictureStatus.txt only once and then I get the same text over and over again. I noticed that if I use some random destination the file is updated. Not sure if it's just random behavior or have something to do with using MyDocuments, but what I need is a way to be sure that I'll rewrite the file with the new data each time, and if possible, use some default destination that will work for other people.
You can try something like this
public partial Form2 : Form
{
public string path = Environment.CurrentDirectory + "/" + "Name.txt";
public Form2()
{
InitializeComponent();
if (!File.Exists(path))
{
File.Create(path);
}
}
private void button2_Click(object sender, EventArgs e)
{
using (StreamWriter sw = new StreamWriter(path, true))
{
sw.WriteLine("This text will be writen in the txt file", true);
sw.Close();
}
}
}
I have add to the button, when I pressed it will be written in the next line every time. If you remove "true" from code, it will be overwritten every time.
I am working on this project still and I am running into a problem. Well here is what I need to do.
When the user clicks the “Save” button, write the selected record to
the file specified in txtFilePath (absolute path not relative) without
truncating the values currently inside and handle any exceptions that arise.
Ok here is my code:
private void Save_Click(object sender, EventArgs e)
{
string filePath = txtFilePath.Text;
if (!File.Exists(filePath))
{
FileStream fs = File.Create(filePath);
fs.Close();
}
using (FileStream fs = new FileStream(filePath, FileMode.Create, FileAccess.Write))
{
using (StreamWriter sw = new StreamWriter(fs))
{
foreach (string line in employeeList.Items)
{
sw.WriteLine(line);
}
}
}
}
Now when I go onto my program and want to save something from the employeelist.text that its not being saved to the place I am saving it at. I don;t know if I am missing something in my code or what but it will not save. Here is an example:
I add a person name to this list in employeelist and in the textbox I
have a file called C:\employess\employeelist.txt I want to save it to.
I click the save button then I go to that employeelist and it is not
being saved.
I don't know what I am doing wrong I have been looking online for a solution but I haven't found anything yet. Thanks
Some things to double-check:
Make sure you don't have the employeelist.txt file open when you're testing
Make sure you don't have invalid characters in your file name
Make sure your application has permission to save the file to the location you specified
Use the debugger to step-through your code and look for swallowed exceptions -- there must be a reason the file is not created.
Check that your Save_Click event is wired up to your button -- is the code in your example even running?
Once you check those things, you may want to follow this example for the create vs. append requirement of your project:
string path = txtFilePath.Text;
// This text is added only once to the file.
if (!File.Exists(path))
{
using (StreamWriter sw = File.CreateText(path))
{
foreach (var line in employeeList.Items)
sw.WriteLine(line.ToString());
}
}
else
{
using (StreamWriter sw = File.AppendText(path))
{
foreach (var line in employeeList.Items)
sw.WriteLine(line.ToString());
}
}
This will create the file if it doesn't exist, or append to it if it does.
Checking that the file exists and then creating it is a bit unnecessary as this can all be handled by the StreamWriter/FileStream parts. So your above function can be simplified into the following:
public void Save_Click(object sender, EventArgs e)
{
StreamWriter file =
new StreamWriter(txtFilePath.Text, true);//Open and append
foreach (object item in employeeList.Items) {
file.WriteLine(item.toString());
}
file.Close();
}
[Updated]
What are the types of txtFilePath and employeeList the former suggests it's a text box, the later suggests it's bound to a non-GUI element perhaps? (WAG)
You might also want to append a blank line at the end so that on further saves you can tell it was an append rather than one long list (depending on your needs of course)
Starting with .Net Framework 4 you can do it like this:
private void Save_Click(object sender, EventArgs e)
{
File.AppendAllLines(txtFilePath.Text, employeeList.Items);
}
Of course, you probably would want to add a check to have a valid path and a valid enumeration of strings.
If the path looks like a relative one (i.e. doesn't begin with a drive letter), then it will be interpreted that way.
If you put a full path in the text box, does the file get saved in the proper place? If so, perhaps this is what was intended.
If the user doesn't put in a full path, do you have a way to make it one (for example, just sticking C:\ at the beginning)? Or at least can you tell when there isn't a full path, and reject the request?