I have a very basic C# WinForms application to generate random numbers. The code is shown below:
private static double RandomNumber(double min, double max)
{
Random random = new Random();
var next = random.NextDouble();
return min +(next * (max - min));
}
private void btnGenerate_Click(object sender, EventArgs e)
{
var maxNum = Convert.ToDouble(txbInput.Text);
var randomDec = Math.Round(RandomNumber(0, maxNum), 2);
txbResult.Text = randomDec.ToString();
}
Now what I want do be able to do is on the button click save the random number that is generated in a locally saved file, along with a timestamp.
I am fairly new to C# and have a limited knowledge on how to do this. Therefore any suggestions would be highly appreciated.
These examples show various ways to write text to a file. The first two examples use static methods on the System.IO.File class to write either a complete array of strings or a complete string to a text file. Example #3 shows how to add text to a file when you have to process each line individually before writing to the file. Examples 1-3 all overwrite all existing content in the file. Example #4 shows how to append text to an existing file.
class WriteTextFile
{
static void Main()
{
// These examples assume a "C:\Users\Public\TestFolder" folder on your machine.
// You can modify the path if necessary.
// Example #1: Write an array of strings to a file.
// Create a string array that consists of three lines.
string[] lines = { "First line", "Second line", "Third line" };
// WriteAllLines creates a file, writes a collection of strings to the file,
// and then closes the file.
System.IO.File.WriteAllLines(#"C:\Users\Public\TestFolder\WriteLines.txt", lines);
// Example #2: Write one string to a text file.
string text = "A class is the most powerful data type in C#. Like a structure, " +
"a class defines the data and behavior of the data type. ";
// WriteAllText creates a file, writes the specified string to the file,
// and then closes the file.
System.IO.File.WriteAllText(#"C:\Users\Public\TestFolder\WriteText.txt", text);
// Example #3: Write only some strings in an array to a file.
// The using statement automatically closes the stream and calls
// IDisposable.Dispose on the stream object.
using (System.IO.StreamWriter file = new System.IO.StreamWriter(#"C:\Users\Public\TestFolder\WriteLines2.txt"))
{
foreach (string line in lines)
{
// If the line doesn't contain the word 'Second', write the line to the file.
if (!line.Contains("Second"))
{
file.WriteLine(line);
}
}
}
// Example #4: Append new text to an existing file.
// The using statement automatically closes the stream and calls
// IDisposable.Dispose on the stream object.
using (System.IO.StreamWriter file = new System.IO.StreamWriter(#"C:\Users\Public\TestFolder\WriteLines2.txt", true))
{
file.WriteLine("Fourth line");
}
}
}
//Output (to WriteLines.txt):
// First line
// Second line
// Third line
//Output (to WriteText.txt):
// A class is the most powerful data type in C#. Like a structure, a class defines the data and behavior of the data type.
//Output to WriteLines2.txt after Example #3:
// First line
// Third line
//Output to WriteLines2.txt after Example #4:
// First line
// Third line
// Fourth line
Reference from here
add this:
// using System.IO;
string filepath = #"C:\test.txt"; //sample file name & location
using (StreamWriter writer = new StreamWriter(filepath))
{
writer.WriteLine(DateTime.Now.ToString() + " " + randomDec.ToString());
} // write your text in a string
To save your text to a file you need to use the IO namespace:
System.IO.File.AppendAllText(#"C:\Test.txt", txbResult && DateTime.Now.ToString());
This stuff show you how to write a string value to a file.
EDIT: Added the timestamp value.
From the wise words of MSDN:
// Example #2: Write one string to a text file.
string text = "A class is the most powerful data type in C#. Like a structure, " +
"a class defines the data and behavior of the data type. ";
// WriteAllText creates a file, writes the specified string to the file,
// and then closes the file.
System.IO.File.WriteAllText(#"C:\Users\Public\TestFolder\WriteText.txt", text);
Please refer to the documentation for more details and examples.
Edit:
Mine's missing the time stamp, but there are plenty of worthy answers here that add it :)
private void WriteData(double value)
{
using (var file = new System.IO.StreamWriter(#"C:\file.txt", true))
{
file.WriteLine(string.Format("{0} {1}", value, DateTime.Now));
}
}
You can see this link msdn. Get the time - DateTime.Now.
Related
I'm running a test where i need to validate data from a linux file. I've defined the path of the file is located (see below). Once i cat the file to read the data contents (irm_dwge_stt_l__xxxx.csv.ovr) how can i validate the data within this file
Also where i have defined the measurementName where can i define what measurements belong within this.
public string validateMeasurement(string measurementName, string domaianName)
{
var processFilePath = "/inputs/ff/ff/actuals/" + measurementName + ".csv.ovr";
var actualItemData = Common.LinuxCommandExecutor.RunLinuxcommand("cat " + processFilePath);
return actualItemData;
}
One way of reading data in C# is to use File.Open.
Running cat and capturing the output is probably not the way to go.
This C# example from https://learn.microsoft.com/en-us/dotnet/csharp/programming-guide/file-system/how-to-read-a-text-file-one-line-at-a-time shows you how to read a file line by line.
You can then compare the file line by line to whatever data you are validating against.
Notice, this will probably only works if you are trying to validate a text file.
int counter = 0;
string line;
// Read the file and display it line by line.
System.IO.StreamReader file =
new System.IO.StreamReader(#"c:\test.txt");
while((line = file.ReadLine()) != null)
{
System.Console.WriteLine (line);
counter++;
}
file.Close();
System.Console.WriteLine("There were {0} lines.", counter);
// Suspend the screen.
System.Console.ReadLine();
I currently am making a UI for a note keeper and was just going to preview documents etc, but i was wondering what file type i would need to create if instead i wanted to do things like tag the file etc, preferably in c#, basically make my own evernote, how do these programs store the notes?
I dont know how to directly tag the file, but you could create your own system to do it. I mentioned two ways to do it:
The first way is to format the note's / file's contents so that there are two parts, the tags and the actual text. When the program loads the note / file, it seperates the tags and the text. This has the downside that the program have to load the whole file to just find the tags.
The second way is to have a database with the filename and it's associated tags. In this way the program doesn't have to load the whole file just to find the tags.
The first way
In this solution you need to format your files in a specific way
<Tags>
tag1,tag2,tag3
</Tags>
<Text>
The text you
want in here
</Text>
By setting up the file like this, the program can separate the tags from the text. To load it's tags you'd need this code:
public List<string> GetTags(string filePath)
{
string fileContents;
// read the file if it exists
if (File.Exists(filePath))
fileContents = File.ReadAllText(filePath);
else
return null;
// Find the place where "</Tags>" is located
int tagEnd = fileContents.IndexOf("</Tags>");
// Get the tags
string tagString = fileContents.Substring(6, tagEnd - 6).Replace(Environment.NewLine, ""); // 6 comes from the length of "<Tags>"
return tagString.Split(',').ToList();
}
Then to get the text you'd need this:
public string GetText(string filePath)
{
string fileContents;
// read the file if it exists
if (File.Exists(filePath))
fileContents = File.ReadAllText(filePath);
else
return null;
// Find the place where the text content begins
int textStart = fileContents.IndexOf("<Text>") + 6 + Environment.NewLine.Length; // The length on newLine is neccecary because the line shift after "<Text>" shall NOT be included in the text content
// Find the place where the text content ends
int textEnd = fileContents.LastIndexOf("</Text>");
return fileContents.Substring(textStart, textEnd - textStart - Environment.NewLine.Length); // The length again to NOT include a line shift added earlier by code
}
Then I'll let you find out how you do the rest.
The second way
In this solution you have a database file over all your files and their associated tags. This database file would look like this:
[filename]:[tags]
file.txt:tag1, tag2, tag3
file2.txt:tag4, tag5, tag6
The program will then read the file name and the tags in this way:
public static void LoadDatabase(string databasePath)
{
string[] fileContents;
// End process if database doesn't exist
if (File.Exists(databasePath))
return;
fileContents = File.ReadAllLines(databasePath); // Read all lines seperately and put them into an array
foreach (string str in fileContents)
{
string fileName = str.Split(':')[0]; // Get the filename
string tags = str.Split(':')[1]; // Get the tags
// Do what you must with the information
}
}
I hope this helps.
I am new to programming and am working on a C# project that will search and replace certain words in a text file with new values. I have some code that works, but the OLD and NEW values are hardcoded right now. I would like to use an external CSV file as a configuration file so the user can add or update the OLD to NEW mappings at a later time. This is my current code with the OLD and NEW values hardcoded:
try
{
StreamReader file = new StreamReader(inputfullfilepath);
TextWriter writer = new StreamWriter(outputfile);
while ((line = file.ReadLine()) != null)
{
line = line.Replace("OLD1", "NEW1");
line = line.Replace("OLD2", "NEW2");
// etc....
writer.WriteLine(line);
}
file.Close();
File.Move(inputfullfilepath, inputfullfilepath + ".old");
writer.Close();
File.Move(outputfile, outputfilepath + #"\" + inputfilename);
MessageBox.Show("File Scrub Complete", "Success");
}
catch
{
MessageBox.Show("Error: Be sure data paths are valid.", "Error",
MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
}
The code takes each line of the text file, tries to do a search/replace for all OLD to NEW mappings, then goes to the next line in the text file. The problem I am trying to wrap my head around is being able to make this list of OLD to NEW mappings dynamic based on a CSV (or XML if that would be easier?) configuration file so the user can add new search/replace keywords.
I tried to use the C# Application Settings in Visual Studio (which creates an XML configuration file) but I had a really hard time understanding how to make that work. What's the best way to do this so the values don't have to be hardcoded?
A csv file will work just fine.
I'll create a new Object which i'll call ReplaceObject
public ReplaceObject()
{
public string original;
public string updated;
//ideally you'd use getters and setters, but I'll keep it simple
}
Now we read from the csv
List<ReplaceObject> replaceList = new List<ReplaceObject>
while (reader.peek != -1)
{
string line = reader.readln();
var splitLine = line.split(',');
ReplaceObject rObject = new ReplaceObject();
rObject.original = splitLine[0];
rObject.updated = splitLine[1];
replaceList.add(rObject);
}
Now we go through the list.. and replace
string entireFile = //read all of it
foreach (ReplaceObject o in replaceList)
{
entireFile.Replace(o.original,o.updated);
}
//write it at the end
(Note that my code is missing some checks, but you should get the idea. Also you might want to use a StringBuilder)
My suggestion would be that you use the Settings.cs instead of CSV
It is very easy to use them and involves very less code
e.g. Properties.Settings.Default.Old1;
Here is a walkthrough http://msdn.microsoft.com/en-us/library/aa730869(v=vs.80).aspx
See this example showing how you can use it http://www.codeproject.com/Articles/17659/How-To-Use-the-Settings-Class-in-C
I am able to do read/write/append operation on text file storing in isolated storage in WP7 application.
My scenario is that I am storing space seperated values in text file inside isolated storage.
So if I have to find for some particular line having some starting key then how to overwrite
value for that key without affecting the other line before and after it.
Example:
Key Value SomeOtherValue
*status read good
status1 unread bad
status2 null cantsay*
So if I have to change the whole second line based on some condition with key as same
status1 read good
How can I achieve this?
There are a number of ways you could do this, and the method you choose should be best suited to the size and complexity of the data file.
One option to get you started is to use the static string.Replace() method. This is crude, but if your file is only small then there is nothing wrong with it.
class Program
{
static void Main(string[] args)
{
StringBuilder sb = new StringBuilder();
sb.AppendLine("*status read good");
sb.AppendLine("status1 unread bad");
sb.AppendLine("status2 null cantsay*");
string input = sb.ToString();
var startPos = input.IndexOf("status1");
var endPos = input.IndexOf(Environment.NewLine, startPos);
var modifiedInput = input.Replace(oneLine.Substring(startPos, endPos - startPos), "status1 read good");
Console.WriteLine(modifiedInput);
Console.ReadKey();
}
}
If you store this information in text files then there won't be a way around replacing whole files. The following code does exactly this and might even be what you are doing right now.
// replace a given line in a given text file with a given replacement line
private void ReplaceLine(string fileName, int lineNrToBeReplaced, string newLine)
{
using (IsolatedStorageFile isf = IsolatedStorageFile.GetUserStoreForApplication())
{
// the memory writer will hold the read and modified lines
using (StreamWriter memWriter = new StreamWriter(new MemoryStream()))
{
// this is for reading lines from the source file
using (StreamReader fileReader = new StreamReader(new IsolatedStorageFileStream(fileName, System.IO.FileMode.Open, isf)))
{
int lineCount = 0;
// iterate file and read lines
while (!fileReader.EndOfStream)
{
string line = fileReader.ReadLine();
// check if this is the line which should be replaced; check is done by line
// number but could also be based on content
if (lineCount++ != lineNrToBeReplaced)
{
// just copy line from file
memWriter.WriteLine(line);
}
else
{
// replace line from file
memWriter.WriteLine(newLine);
}
}
}
memWriter.Flush();
memWriter.BaseStream.Position = 0;
// re-create file and save all lines from memory to this file
using (IsolatedStorageFileStream fileStream = new IsolatedStorageFileStream(fileName, System.IO.FileMode.Create, isf))
{
memWriter.BaseStream.CopyTo(fileStream);
}
}
}
}
private void button1_Click(object sender, RoutedEventArgs e)
{
ReplaceLine("test.txt", 1, "status1 read good");
}
And I agree with slugster: using SQLCE database might be a solution with better performance.
I am sending mails (in asp.net ,c#), having a template in text file (.txt) like below
User Name :<User Name>
Address : <Address>.
I used to replace the words within the angle brackets in the text file using the below code
StreamReader sr;
sr = File.OpenText(HttpContext.Current.Server.MapPath(txt));
copy = sr.ReadToEnd();
sr.Close(); //close the reader
copy = copy.Replace(word.ToUpper(),"#" + word.ToUpper()); //remove the word specified UC
//save new copy into existing text file
FileInfo newText = new FileInfo(HttpContext.Current.Server.MapPath(txt));
StreamWriter newCopy = newText.CreateText();
newCopy.WriteLine(copy);
newCopy.Write(newCopy.NewLine);
newCopy.Close();
Now I have a new problem,
the user will be adding new words within an angle, say for eg, they will be adding <Salary>.
In that case i have to read out and find the word <Salary>.
In other words, I have to find all the words, that are located with the angle brackets (<>).
How do I do that?
Having a stream for your file, you can build something similar to a typical tokenizer.
In general terms, this works as a finite state machine: you need an enumeration for the states (in this case could be simplified down to a boolean, but I'll give you the general approach so you can reuse it on similar tasks); and a function implementing the logic. C#'s iterators are quite a fit for this problem, so I'll be using them on the snippet below. Your function will take the stream as an argument, will use an enumerated value and a char buffer internally, and will yield the strings one by one. You'll need this near the start of your code file:
using System.Collections.Generic;
using System.IO;
using System.Text;
And then, inside your class, something like this:
enum States {
OUT,
IN,
}
IEnumerable<string> GetStrings(TextReader reader) {
States state=States.OUT;
StringBuilder buffer;
int ch;
while((ch=reader.Read())>=0) {
switch(state) {
case States.OUT:
if(ch=='<') {
state=States.IN;
buffer=new StringBuilder();
}
break;
case States.IN:
if(ch=='>') {
state=States.OUT;
yield return buffer.ToString();
} else {
buffer.Append(Char.ConvertFromUtf32(ch));
}
break;
}
}
}
The finite-state machine model always has the same layout: while(READ_INPUT) { switch(STATE) {...}}: inside each case of the switch, you may be producing output and/or altering the state. Beyond that, the algorithm is defined in terms of states and state changes: for any given state and input combination, there is an exact new state and output combination (the output can be "nothing" on those states that trigger no output; and the state may be the same old state if no state change is triggered).
Hope this helps.
EDIT: forgot to mention a couple of things:
1) You get a TextReader to pass to the function by creating a StreamReader for a file, or a StringReader if you already have the file on a string.
2) The memory and time costs of this approach are O(n), with n being the length of the file. They seem quite reasonable for this kind of task.
Using regex.
var matches = Regex.Matches(text, "<(.*?)>");
List<string> words = new List<string>();
for (int i = 0; i < matches.Count; i++)
{
words.Add(matches[i].Groups[1].Value);
}
Of course, this assumes you already have the file's text in a variable. Since you have to read the entire file to achieve that, you could look for the words as you are reading the stream, but I don't know what the performance trade off would be.
This is not an answer, but comments can't do this:
You should place some of your objects into using blocks. Something like this:
using(StreamReader sr = File.OpenText(HttpContext.Current.Server.MapPath(txt)))
{
copy = sr.ReadToEnd();
} // reader is closed by the end of the using block
//remove the word specified UC
copy = copy.Replace(word.ToUpper(), "#" + word.ToUpper());
//save new copy into existing text file
FileInfo newText = new FileInfo(HttpContext.Current.Server.MapPath(txt));
using(var newCopy = newText.CreateText())
{
newCopy.WriteLine(copy);
newCopy.Write(newCopy.NewLine);
}
The using block ensures that resources are cleaned up even if an exception is thrown.