It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center.
Closed 10 years ago.
Were trying to use external file (txt or CSV) in order to create a file stream in C#.
The data in the file is that of a quiz game made of :
1 short question
4 possibles answers
1 correct answer
The program should be able to tell the user whether he answered correctly or not.
I'm looking for an example code/algorithm/tutorial on how to use the data in the external file to create a simple quiz in C#.
Also, any suggestions on how to construct the txt file (how do I remark an answer as the correct one?).
Any suggestions or links?
Thanks,
My recommendation would be to use an XML file if you must load your data from a file (as opposed to from a database).
Using a text file would require you to pretty clearly define structure for individual elements of the question. Using a CSV could work, but you'd have to define a way to escape commas within the question or answer itself. It might complicate matters.
So, to reiterate, IMHO, an XML is the best way to store such data. Here is a short sample demonstrating the possible structure you might use:
<?xml version="1.0" encoding="utf-8" ?>
<Test>
<Problem id="1">
<Question>Which language am I learning right now?</Question>
<OptionA>VB 7.0</OptionA>
<OptionB>J2EE</OptionB>
<OptionC>French</OptionC>
<OptionD>C#</OptionD>
<Answer>OptionA</Answer>
</Problem>
<Problem id="2">
<Question>What does XML stand for?</Question>
<OptionA>eXtremely Muddy Language</OptionA>
<OptionB>Xylophone, thy Music Lovely</OptionB>
<OptionC>eXtensible Markup Language</OptionC>
<OptionD>eXtra Murky Lungs</OptionD>
<Answer>OptionC</Answer>
</Problem>
</Test>
As far as loading an XML into memory is concerned, .NET provides many intrinsic ways to handle XML files and strings, many of which completely obfuscate having to interact with FileStreams directly. For instance, the XmlDocument.Load(myFileName.xml) method will do it for you internally in one line of code. Personally, though I prefer to use XmlReader and XPathNavigator.
Take a look at the members of the System.Xml namespace for more information.
There's really no set way to do this, though I would agree that for a simple database of quiz questions, text files would probably be your best option (as opposed to XML or a proper database, though the former wouldn't be completely overkill).
Here's a little example of a text-based format for a set of quiz questions, and a method to read the questions into code. Edit: I've tried to make it as easy as possible to follow now (using simple constructions), with plenty of comments!
File Format
Example file contents.
Question text for 1st question...
Answer 1
Answer 2
!Answer 3 (correct answer)
Answer 4
Question text for 2nd question...
!Answer 1 (correct answer)
Answer 2
Answer 3
Answer 4
Code
This is just a simple structure for storing each question in code:
struct Question
{
public string QuestionText; // Actual question text.
public string[] Choices; // Array of answers from which user can choose.
public int Answer; // Index of correct answer within Choices.
}
You can then read the questions from the file using the following code. There's nothing special going on here other than the object initializer (basically this just allows you to set variables/properties of an object at the same time as you create it).
// Create new list to store all questions.
var questions = new List<Question>();
// Open file containing quiz questions using StreamReader, which allows you to read text from files easily.
using (var quizFileReader = new System.IO.StreamReader("questions.txt"))
{
string line;
Question question;
// Loop through the lines of the file until there are no more (the ReadLine function return null at this point).
// Note that the ReadLine called here only reads question texts (first line of a question), while other calls to ReadLine read the choices.
while ((line = quizFileReader.ReadLine()) != null)
{
// Skip this loop if the line is empty.
if (line.Length == 0)
continue;
// Create a new question object.
// The "object initializer" construct is used here by including { } after the constructor to set variables.
question = new Question()
{
// Set the question text to the line just read.
QuestionText = line,
// Set the choices to an array containing the next 4 lines read from the file.
Choices = new string[]
{
quizFileReader.ReadLine(),
quizFileReader.ReadLine(),
quizFileReader.ReadLine(),
quizFileReader.ReadLine()
}
};
// Initially set the correct answer to -1, which means that no choice marked as correct has yet been found.
question.Answer = -1;
// Check each choice to see if it begins with the '!' char (marked as correct).
for(int i = 0; i < 4; i++)
{
if (question.Choices[i].StartsWith("!"))
{
// Current choice is marked as correct. Therefore remove the '!' from the start of the text and store the index of this choice as the correct answer.
question.Choices[i] = question.Choices[i].Substring(1);
question.Answer = i;
break; // Stop looking through the choices.
}
}
// Check if none of the choices was marked as correct. If this is the case, we throw an exception and then stop processing.
// Note: this is only basic error handling (not very robust) which you may want to later improve.
if (question.Answer == -1)
{
throw new InvalidOperationException(
"No correct answer was specified for the following question.\r\n\r\n" + question.QuestionText);
}
// Finally, add the question to the complete list of questions.
questions.Add(question);
}
}
Of course, this code is rather quick and basic (certainly needs some better error handling), but it should at least illustrate a simple method you might want to use. I do think text files would be a nice way to implement a simple system such as this because of their human readability (XML would be a bit too verbose in this situation, IMO), and additionally they're about as easy to parse as XML files. Hope this gets you started anyway...
A good place to start is with Microsoft's documentation on FileStream.
A quick google search will give you pretty much everything you need. Here's a tutorial on reading and writing files in C#. Google is your friend.
any suggestions on how to construct the txt file (how do I remark an answer as the correct one?)
Perhaps the easiest is with a simple text file format - where you have questions and answers on each line (no blank lines). The # sign signifies the correct answer.
Format of the file -
Question
#answer
answer
answer
answer
An example file -
What is 1 + 1?
#2
9
3
7
Who is buried in Grant's tomb?
Ed
John
#Grant
Tim
I'm looking for an example code/algorithm/tutorial on how to use the data in the external file to create a simple quiz in C#.
Here's some code that uses the example file to create a quiz.
static void Main(string[] args)
{
int correct = 0;
using (StreamReader sr = new StreamReader("C:\\quiz.txt"))
{
while (!sr.EndOfStream)
{
Console.Clear();
for (int i = 0; i < 5; i++)
{
String line = sr.ReadLine();
if (i > 0)
{
if (line.Substring(0, 1) == "#") correct = i;
Console.WriteLine("{0}: {1}", i, line);
}
else
{
Console.WriteLine(line);
}
}
for (; ; )
{
Console.Write("Select Answer: ");
ConsoleKeyInfo cki = Console.ReadKey();
if (cki.KeyChar.ToString() == correct.ToString())
{
Console.WriteLine(" - Correct!");
Console.WriteLine("Press any key for next question...");
Console.ReadKey();
break;
}
else
{
Console.WriteLine(" - Try again!");
}
}
}
}
}
Related
Closed. This question needs to be more focused. It is not currently accepting answers.
Want to improve this question? Update the question so it focuses on one problem only by editing this post.
Closed 2 years ago.
Improve this question
I am creating a simple WPF Program that will read and write .txt files for a simple character switcher/scrambler.
I want to be able to create a list of Definitions in a file for every character to replace it with another character that will be used to switch the characters when its ran.
for example:
a = x
b = r
c = e
d = u
and so on
So essentially I to want be able to select a .txt file and run a C# script when my button is pressed that will replace all characters in the .txt file with the predefined definition of it from the list above and save that changed version as a .txt file. I also want to be able to select the changed .txt file and revert it to the original characters if possible when another button is pressed.
I already have the WPF program set up with the buttons and File directory stuff, I need help with the C# implementation of actually making this idea work as I can't find any resources online that are covering what I am describing. Any guidance on where to look and or what to do next would be appreciated.
First you need to read your mapping file and create a map. I pondered a few ways of doing this but easiest is probably to use a dictionary
var config = File.ReadAllLines(...);
//declare these at class level probably, I only put here to make my code work and show the definition
var scramble = new Dictionary<char, char>();
var unscramble = new Dictionary<char, char>();
foreach(var line in config){
var a = line.First();
var b = line.Last();
scramble[a] = b;
unscramble[b] = a;
}
Then you have to process your file. It would be more memory efficient to read char by char using a StreamReader than to read to as a string and convert to char (needs twice the memory) but I'll leave that as an exercise for the reader. Here I take the quick and dirty method of reading the file and then turning it into a char array immediately, but it briefly requires twice the memory as the file is big:
var chars = File.ReadAllText(...).ToArray();
for(int i = 0; i < chars.Length; i++)
if(scramble.ContainsKey(chars[i]))
chars[i] = scramble[chars[i]];
Writing the chars array to disk as the newly scrambled file is an exercise for you. Unscrambling is a similar pattern
Step 1) let's get the text into a format that we can read through.
var FileText = File.ReadAllText(filename.txt).ToArray();
Step 2) we need to decide how to find the characters in the string. A very basic way to achieve this is going to be to loop through the string that we have searching for our characters.
for (int i = 0; i < FileText.length; i++)
{
switch (FileText[i])
{
case 'a':
FileText[i] = 'x';
break;
... // Fill out cases for each substitution
default:
// This character is something we don't care about, so keep looping
continue;
}
}
There are very likely more efficient solutions, but this will at least get the job done while not being too complex.
Edit:
As per Caius' comment, the assignment to a string indexer doesn't work. It needed to be a character array. I tested the change, and it seems to work now. The downside of this solution is it is not configurable, though.
For a customer of mine I need to force the spell checking in a certain language.
I have explored the MSDN documentation and found that when calling the CheckSpelling() method in the active document, it will invoke the spelling check. This method has parameters for custom dictionaries.
My problem is that I can't find anything about those dictionaries or how to use them.
Also there is still the possibility that there is of course another way to do this.
Can anybody boost me in the right direction?
Found my solution:
foreach (Range range in activeDocument.Words)
{
range.LanguageID = WdLanguageID.wdFrenchLuxembourg;
}
Edit after comment
Since my activedocument is in a variable I seem to lose the static Range property. I found a work arround by doing the following. (lan is my variable where i keep my WdLanguageId)
object start = activeDocument.Content.Start;
object end = activeDocument.Content.End;
activeDocument.Range(ref start, ref end).LanguageID = lan;
thanks #Adrianno for all the help!
The Spell Checker uses the language of the text to select rules and dictionaries (look here to check how it works).
You have to set the text language to what you need and then SC will use that language. Follow this link for more details:
http://msdn.microsoft.com/en-us/library/microsoft.office.interop.word.language.aspx
I have been working with this lately and thought I would add a bit to the already given answers.
To get a list of spelling errors in the document for a certain language, doing the following would get you going:
// Set the proofing language
myDocument.Content.LanguageID = WdLanguageID.wdDanish;
// Get the spelling errors (returns a ProofreadingErrors collection)
var errors = myDocument.SpellingErrors;
// There is no "ProofreadingError" object -> errors are accessed as Ranges
foreach (Range proofreadingError in errors)
Console.WriteLine(proofreadingError.Text);
As pointed out by Adriano, the key is to specify the language of the document content at first, and then you can access the spelling errors for the given language. I have tested this (Word Interop API version 15, Office 2013), and it works.
If you want to get suggestions for each of the misspelled words as well, I suggest you take a look at my previous answer to that issue: https://stackoverflow.com/a/14202099/700926
In that answer I provide sample code as well as links to relevant documentation for how that is done. In particular, the sample covers how to carry out spell checking of a given word in a certain language (of your choice) using Word Interop. The sample also covers how to access the suggestions returned by Word.
Finally, I have a couple of notes:
In contrast to the current accepted answer (your own) - this approach is much faster since it do not have to iterate through each word. I have been working with Word Interop for reports (100+ pages) and trust me, you don't want to sit and wait for that iteration to finish.
Information regarding the SpellingErrors property can be found here.
Information regarding the non-existence of a ProofreadingError object can be found here.
Never user foreach statements when accessing Office object. Most of the Office objects are COM object, and using foreach leads to memory leaks.
The following is a piece of working code
Microsoft.Office.Interop.Word.ProofreadingErrors errorCollection = null;
try
{
errorCollection = Globals.ThisAddIn.Application.ActiveDocument.SpellingErrors;
// Indexes start at 1 in Office objects
for (int i = 1; i <= errorCollection .Count; i++)
{
int start = errorCollection[i].Start;
int end = errorCollection[i].End;
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
// Release the COM objects here
// as finally shall be always called
if (errorCollection != null)
{
Marshal.ReleaseComObject(errorCollection);
errorCollection = null;
}
}
I want to provide the user with a selection of questions but I want them to be random, having a quiz game with the same questions isn't exactly fun.
My idea was to store a large collection of questions and there appropiate answers in a text file:
What colour is an Strawberry|Red
How many corners are there on a Triangle|Three
This means that I could simply select a line at random, read the question and answer from the line and store them in a collection to be used in the game.
I've come up with some pseudo code with an approach I think would be useful and am looking for some input as to how it could be improved:
Random rand = new Random();
int line;
string question,answer;
for(int i = 0; i < 20; i++)
{
line = rand.Next();
//Read question at given line number to string
//Read answer at given line number to string
//Copy question and answer to collection
}
In terms of implementing the idea I'm unsure as to how I can specify a line number to read from as well as how to split the entire line and read both parts separately. Unless there's a better way my thoughts are manually entering a line number in the text file followed by a "|" so each line looks like this:
1|What colour is an Strawberry|Red
2|How many corners are there on a Triangle|Three
Thanks for any help!
Why not read the entire file into an array or a list using ReadLine and then refer to a random index within the bounds of the array to pull the question/answer string from, rather than reading from the text file when you want a question.
As for parsing it, just use Split to split it at the | delineator (and make sure that no questions have a | in the question for some reason). This would also let you store some wrong answers with the question (just say that the first one is always right, then when you output it you can randomize the order).
You don't want to display any questions twice, right?
Random random = new Random();
var q = File.ReadAllLines("questions.txt")
.OrderBy(x=>random.Next())
.Take(20)
.Select(x=>x.Split('|'))
.Select(x=>new QuestionAndAnswer(){Question=x[0],Answer=x[1]});
as a small (large) hobby project I've set out to make a (very primitive) ssh-2.0 client in C#.
This is to explore and better understand DH and help flourish my encryption familiarities :)
As per RFC 4253, I've begun the initial connection like this:
(leaving out irrelevant presetting of vars etc.)
Random cookie_gen = new Random();
while ((ssh_response = unsecure_reader.ReadLine()) != null)
{
MessageBox.Show(ssh_response);
if (ssh_response.StartsWith("SSH-2.0-")
{
// you told me your name, now I'll tell you mine
ssh_writer.Write("SSH-2.0-MYSSHCLIENT\r\n");
ssh_writer.Flush();
// now I should write up my supported (which I'll keep to the required as per rfc 4253)
ssh_writer.Write(0x20); // SSH_MSG_KEXINIT
byte[] cookie = new byte[16];
for (int i = 0; i < 16; i++)
cookie[i] = Convert.ToByte(cookie_gen.Next(0, 10));
ssh_writer.Write(cookie); // cookie
// and now for the name-list
// This is where I'm troubled
// "Footer"
ssh_writer.Write(0x00); // first_kex_packet_follows
ssh_writer.Write(0x00); // 0
ssh_writer.Flush();
}
}
As you can see on page 16 of RFC 4253, I'm expected to give 10 name-lists. Are these simply suppose to be strings, or how do I mark start/end of each list (simply by newline \n)? Am I even on the right track here? (keep in mind I will handle DH and encryption past this point. My question is solely based on the initial contact so far).
Any help or comments are welcomed and appreciated,
PS: I'm aware libraries exist, but this is not relevant to my project.
Well, as RFC 4251 states on page 9:
Terminating null characters MUST NOT be used, neither
for the individual names, nor for the list as a whole.
There are also examples in the named RFC.
As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance.
Closed 10 years ago.
I'm looking at parsing a delimited string, something on the order of
a,b,c
But this is a very simple example, and parsing delimited data can get complex; for instance
1,"Your simple algorithm, it fails",True
would blow your naiive string.Split implementation to bits. Is there anything I can freely use/steal/copy and paste that offers a relatively bulletproof solution to parsing delimited text? .NET, plox.
Update: I decided to go with the TextFieldParser, which is part of VB.NET's pile of goodies hidden away in Microsoft.VisualBasic.DLL.
I use this to read from a file
string filename = #textBox1.Text;
string[] fields;
string[] delimiter = new string[] {"|"};
using (Microsoft.VisualBasic.FileIO.TextFieldParser parser =
new Microsoft.VisualBasic.FileIO.TextFieldParser(filename)) {
parser.Delimiters = delimiter;
parser.HasFieldsEnclosedInQuotes = false;
while (!parser.EndOfData) {
fields = parser.ReadFields();
//Do what you need
}
}
I am sure someone here can transform this to parser a string that is in memory.
A very complrehesive library can be found here: FileHelpers
I am not aware of any framework, but a simple state machine works:
State 1: Read every char until you hit a " or a ,
In case of a ": Move to State 2
In case of a ,: Move to State 3
In case of the end of file: Move to state 4
State 2: Read every char until you hit a "
In case of a ": Move to State 1
In case of the end of the file: Either Move to State 4 or signal an error because of an unterminated string
State 3: Add the current buffer to the output array, move the cursor forward behind the , and back to State 1.
State 4: this is the final state, does nothing except returning the output array.
Such as
var elements = new List<string>();
var current = new StringBuilder();
var p = 0;
while (p < internalLine.Length) {
if (internalLine[p] == '"') {
p++;
while (internalLine[p] != '"') {
current.Append(internalLine[p]);
p++;
}
// Skip past last ',
p += 2;
}
else {
while ((p < internalLine.Length) && (internalLine[p] != ',')) {
current.Append(internalLine[p]);
p++;
}
// Skip past ,
p++;
}
elements.Add(current.ToString());
current.Length = 0;
}
There are some good answers here: Split a string ignoring quoted sections
You might want to rephrase your question to something more precise (e.g. What code snippet or library I can use to parse CSV data in .NET?).
To do a shameless plug, I've been working on a library for a while called fotelo (Formatted Text Loader) that I use to quickly parse large amounts of text based off of delimiter, position, or regex. For a quick string it is overkill, but if you're working with logs or large amounts, it may be just what you need. It works off a control file model similar to SQL*Loader (kind of the inspiration behind it).
Better late than never (add to the completeness of SO):
http://www.codeproject.com/KB/database/CsvReader.aspx
This one ff-ing rules.
GJ
I am thinking that a generic framework would need to specify between two things:
1. What are the delimiting characters.
2. Under what condition do those characters not count (such as when they are between quotes).
I think it may just be better off writing custom logic for every time you need to do something like this.
Simplest way is just to split the string into a char array and look for your string determiners and split char.
It should be relatively easy to unit test.
You can wrap it in an extension method similar to the basic .Spilt method.