c# writing user input from form to text file using windows a

Question

How do i write the user input from my form (windows based application) to a text file?

Vulpes · Answer

File.WriteAllText or File.WriteAllLines creates the file if it doesn't exist already. Otherwise it overwrites the file with the new stuff. Of course, File.ReadAllText or File.ReadAllLines can only read the file if it already exists and I assume that's what you were missing with your own code :)

ICE QUEEN · Answer

vulpes, u still there? Here's the link to the other thread http://www.c-sharpcorner.com/Forums/Thread/211192/

ICE QUEEN · Answer

I started one here System.Collection.IList Please just help me get this writing to file as the sort methods are neally finish i have to have this done in an hour or so. It was actually due 6hours ago

Vulpes · Answer

I'd stick to the user interface design you already have and just try and fix what's not currently working in a methodical fashion. I'll help if I can though I do have other stuff to do today. May be it would be better if you got some sleep first as a clear head is needed for programming.

ICE QUEEN · Answer

I tried uploading but, it was taking too long.. Anyhow, what i have so far, is that the form loads parent window which contains nearlly all the forms controls in the main menu, allowing for ease of navigation when the child form (window) appears depending on user selection... so where to now??? I really need to get this done asap! (like 6 hours ago) :( I'm feeling so stuck right now...

Vulpes · Answer

Although only saving the file when the application ends is easiest and quickest, it does expose you to the risk that changes made in the current session will be lost if the application crashes. So, if you'd be more comfortable saving them as you go along, I'd do that. All you need is a call to a SavePersons method after each change to the List . You don't need any more eventhandlers than you would otherwise have. Incidentally, as this thread is getting very long, I'd start a new one so we don't have to do so much scrolling!

ICE QUEEN · Answer

if it is written every time a user takes place, then this will require the use of event handlers, right? since the nature of the requirements is such that i need to allow the user to be able to add remove and modify requires at any time.. what do u suggest, tbh, i just want it done the quickest way possible so i can get some sleeep...

Vulpes · Answer

You can upload images to the site (5th button on the second row) or to one of the free file sharing sites and then post the link. However, I don't have any problem with how you want to do it which is what we started off with. I just need to be clear how you want it doing. The code I gave in my previous post could be called at any time to save the current state of the List if you place it in a separate method. Rather than mess around, trying to append stuff to the file, it might be easiest just to overwrite the file every time there's a change - whether this be a new person or a change to an existing one.

ICE QUEEN · Answer

do u have an email address/ dropbox i can send u screenshots of what i'm trying to accomplish??? it doesn't specify but since it is MDI i thought it to be better design/ robust to write directly to file. Also that way i know if things are working correctly as i intend...

Vulpes · Answer

I didn't know it was an MDI application but I thought what we were now doing was to: 1. Load the List from the file when the application starts. 2. Add new Person objects to, or amend existing Persons in, the List whilst the application is running. 3. Save the current state of the List back to the file when the application ends. If we're not doing that then what are we doing - saving every change to the file as it occurs?

ICE QUEEN · Answer

vulpes, i dont think we are on the same page.... I have created this application as an MDI so the main page is only closed when the application is closed.. I am under the impression that i need to write to file sooner then that closing the app,

Vulpes · Answer

It should be written to the file when your main form is about to close either because the user has clicked the X button or the Close() method has been called. You can deal with this by handling its FormClosed event: private void Form1_FormClosed(Object sender, FormClosedEventArgs e) { using(StreamWriter sw = new StreamWriter(dataPath)) // need to overwrite existing file { foreach(Person p in persons) { string line = String.Format("{0}|{1}|{2}", p.FirstName, p.LastName, p.Country); sw.WriteLine(line); } } }

ICE QUEEN · Answer

btw using this.Close() to exit the form as an event for Submit, mucks up my validation for the form fields...

ICE QUEEN · Answer

so when the user completes the form (passes) all my validation checks then its written to memory, is that right? so when do we actually right to file??? i really need to get this done, my head is buzzing & i haven't been to sleep yet (in over 28hrs now)

ICE QUEEN · Answer

so then whats next?

Vulpes · Answer

To get a list of all names in your List you can use this method: private List GetPersonNames() { List names = new List (); foreach(Person p in persons) { names.Add(p.FirstName + " " + p.LastName); } return names; } You could then use this method to display the names in a ListBox, say, as follows: listBox1.Items.Clear(); // if necessary foreach(string name in GetPersonNames()) { listBox1.Items.Add(name); } On your other point, it's not writing to the text file because you don't have an sw.WriteLine in there. However, you don't want one anyway as we're doing everything in memory until the application ends. So, I'd have thought you'd just want: private void createNewSalesman() { Salesman s = new Salesman(lNameTextBox.Text, fNameTextBox.Text); salesmanList.Add(s); }

ICE QUEEN · Answer

my code still not working any advice??? vulpes??

ICE QUEEN · Answer

please tell me what is wrong with this code also i am not getting any errors but it doesnt write to my text file: private void createNewSalesman() { using (StreamWriter sw = new StreamWriter(dataPath, true)) { Salesman s = new Salesman(lNameTextBox.Text, fNameTextBox.Text); salesmanList.Add(s); } }

Bhabani prasad Dash · Answer

i want online user and total visitor to my site i take two label to show online user and total user.and write below code in global.asax and for load .but it always show output online user 1 that is correct but total user also 1.so i want when agai i run my application it will show total user2,3,4 so on lbl_onlineuser.Text = Application["onlineuser"].ToString(); lbl_totaluser.Text = Application["Totaluser"].ToString(); void Application_Start(object sender, EventArgs e) { // Code that runs on application startup Application["Totaluser"] = 0; Application["onlineuser"] = 0; } void Application_End(object sender, EventArgs e) { // Code that runs on application shutdown } void Application_Error(object sender, EventArgs e) { // Code that runs when an unhandled error occurs } void Session_Start(object sender, EventArgs e) { // Code that runs when a new session is started Session.Timeout = 20; Session["Start"] = "Now"; Application.Lock(); Application["Totaluser"] = Convert.ToInt32(Application["Totaluser"]) + 1; Application["onlineuser"] = Convert.ToInt32(Application["onlineuser"]) + 1; Application.UnLock(); } void Session_End(object sender, EventArgs e) { // Code that runs when a session ends. // Note: The Session_End event is raised only when the sessionstate mode // is set to InProc in the Web.config file. If session mode is set to StateServer // or SQLServer, the event is not raised. Application.Lock(); Application["onlineuser"] = Convert.ToInt32(Application["onlineuser"]) - 1; Application.UnLock();

ICE QUEEN · Answer

I am having trouble listing all the names of the people in my list ... Any suggestions will be greatly appreciated!!!!

ICE QUEEN · Answer

I am having trouble listing all the names of the people in my list ... Any suggestions will be greatly appreciated!!!!

ICE QUEEN · Answer

yeh i just read that. its 8 o'clock in the morning here & i haven't been to bed yet, need to get this done.. Thanx again for all ur help!

Vulpes · Answer

Yes, you should still change the methods. The idea now is to write to the file only when the application is about to close down. The 'persons' variable should be declared as a private field of the form so that it is accessible to all methods within the form: private List persons = new List (); Some body told me the other day that you now need a minimum of 100 points to use the messaging system on this site. However, it's nearly 1 o'clock in the morning here and so I'm about to go to bed anyway. Will look at it again in the morning if you haven't figured it out by then.

ICE QUEEN · Answer

i just tried declaring it as a string but it didnt like that!! Error: 'string' does not contain a definition for 'Add' and no extension method 'Add' accepting a first argument of type string could be found (are u missing a using directive or an assembly reference) ?????

ICE QUEEN · Answer

persons.Add(p); //error: persons does not exist in the current context, shall i just declare it as a string variable? e.g string persons; ?

ICE QUEEN · Answer

Vulpes, is there a way i can email u directly?

ICE QUEEN · Answer

ok, the weirdest thing happened. The file is now writing after debugging several times. Should i still change the methods? if so, what about writing to file?

Vulpes · Answer

Yes, you can use this.Close() at that point if you want to close the form when the user is done. I don't understand why the code is not generating a new file if it doesn't exist already but it doesn't matter any more as we're now adding a new item to the List rather than writing anything to the file at this stage. So the createNewPerson() method now becomes: private void createNewPerson() { Person p = new Person(fNameTextBox.Text, lNameTextBox.Text); persons.Add(p); } Similarly, the editPerson method now becomes: private void editPerson() { bool personExists = false; for(int i = 0; i { Person p = persons[i]; if (p.FirstName == fNameTextBox.Text && p.LastName == lNameTextBox.Text) { personExists = true; p.Country = countryTextBox.Text; // etc break; } } if (!personExists) // create one and add it to the list { Person p = new Person(fNameTextBox.Text, lNameTextBox.Text); p.Country = countryTextBox.Text; persons.Add(p); } }

ICE QUEEN · Answer

Vulpes, i think i'm a bit confused now.. in my submit button i have: lNameTextBox_Validated(this, e); fNmaeTextBOx_Validated(this, e); createNewPerson(); //CAN I USE this.Close(); here to close the form once the user is done? Also, u said to use the following code but nothing happend?? createNewPerson() { using(StreamWriter sw = new StreamWriter(dataPath, true)) sw.WriteLine("LastName:{0|FirstName: {1}, lNameTextBox, fNameTextBox) } // i checked my path But no file was created??? & no errors are showing???

Vulpes · Answer

The List object needs to be a private field of your form, so it can be accessed by all methods in the form. It doesn't want to be included in the Person class itself. Nor is there any point in creating a new class, just to house methods. You can either put them in the Person class itself or in the form - the latter might be best seeing what you need to do. Here's a method to get a list of people in a given country. Notice that, if there are no persons in that country, an empty List would be returned (Count = 0). private List GetPersonsInCountry(string country) { List list = new List (); foreach(Person p in persons) { if(p.Country == country) list.Add(p); } return list; }

ICE QUEEN · Answer

wow THANX! I'll try it out, saves me from writing an add method aswell! so this list goes in the Person class then??? would u write another class say PersonDB to house all ur methods in?

Vulpes · Answer

You'd create a List like this: List persons = new List (); // create a Person object Person p = new Person("Selwa", "Edries"); // add it to the List persons.Add(p); // retrieve the first person in the List Person p2 = persons[0]; // iterate through the List foreach(Person p in persons) { // do something with 'p' } So, apart from the Add method, it's much the same as an array. Notice though that to get the number of elements in the List it's persons.Count, not persons.Length. You could either use a string or a DateTime for date of birth. I wouldn't use long.

ICE QUEEN · Answer

would u use user input dateOfBirth as a string or a long??

ICE QUEEN · Answer

Thank you so much!!!! yeh i am in the middle of writing a Person class although i am not familiar with using List if u could give me an example & a quick run through on how it works PLSSSSS...

Vulpes · Answer

Well, once created, an array is fixed in size. So, if you used an array, you'd need to impose a maximum on the size of the file. If you used an ArrayList or (better a List ), you wouldn't need to impose a maximum as these collections can automatically increase their size as needed. What you could do is to do everything in memory using one of these collections. You'd only then need to load the file when the program starts and save it when the program ended. If you did this, you'd need a Person class: class Person { public string FirstName {get; set;} public string LastName {get; set;} public string Country {get; set;} // any others public Person(string fName, string lName) // constructor if only names given { FirstName = fName; LastName = lName; Country = ""; } // add another constructor to initialize all fields }

ICE QUEEN · Answer

couldn't i put them all into a peoples array and therefore have just 1 file? that is why i asked ur opinion on instance constructor use????

Vulpes · Answer

Well, it sounds to me like you need to have a single file with each person's data occupying a single line. As you will need to split up the data when you read it back, you'll need to use a separator. I wouldn't use comma or space but a vertical bar '|' as the separator. The code in my last post will now become : private void createNewPerson() { using (StreamWriter sw = new StreamWriter(dataPath, true)) { sw.WriteLine("{0}|{1}", fNameTextBox.Text, lNameTextBox.Text); } } The code for editPerson() will be: private void editPerson() { string[] lines = File.ReadAllLines(dataPath); bool personExists = false; for(int i = 0; i { string[] items = lines[i].Split('|'); if (items[0] == fNameTextBox.Text && items[1] == lNameTextBox.Text) { personExists = true; lines[i] = String.Format("{0}|{1}|{2}|{3}", items[0], items[1], countryTextBox.Text, ageTextBox.Text); // or whatever you want to save break; } } if (personExists) { File.WriteAllLines(dataPath, lines); // save edited file } else { using (StreamWriter sw = new StreamWriter(dataPath, true)) { sw.WriteLine("{0}|{1}|{2}|{3}", fNameTextBox.Text, lNameTextBox.Text, countryTextBox.Text, ageTextBox.Text); // append new person to end of file } } }

Terrance C · Answer

Thanks, for pointing this out. I forgot to mention it. I thought that intellisense would be good enough.

ICE QUEEN · Answer

so any advice on the use of instance constructors for what i need to achieve??

ICE QUEEN · Answer

OK here's what I am trying to achieve: 1. Create a new Person record (based on user input from the form) - only the name fields are mandatory so they can come back later to fill in the rest of the form. 2. List ALL the names in the system. (that was obviously saved in 1 above) 3. List the names of those people whose names contain a given string(user input). Eg: given string = "Tim", all Tim's will show: eg. "Tim Taylor", "Jack Tims", "Tomothy Smith". 4. List the people from a given country 5. Bring up the Person record by clicking the name of the person from the Person list in 2,3 & 4 above and allow the user to modify the record...... I still have alooot today :___ ( so i really appreciate the help!!!

Vulpes · Answer

On the first point, the StreamWriter constructor has an overload where if you pass 'true' as the second parameter it will append to an existing file rather than overwrite it. It will still create a new file if the file doesn't already exist. So try: private void createNewPerson() { using (StreamWriter sw = new StreamWriter(dataPath, true)) { sw.WriteLine("First Name = " + fNameTextBox.Text); sw.WriteLine("Last Name = " + lNameTextBox.Text); } } On the second point, does each person have his/her own file or is there just one file for everybody?

ICE QUEEN · Answer

ok, i think my brain is fried! it just clicked for my last post i will have an editPerson(). What about the use of instance concstructors in this case?

ICE QUEEN · Answer

because only the name fields are required a person may choose to come back at a later date to fill in the form, that is why i require append but then how will i get it to append to the correct 'person'???

ICE QUEEN · Answer

how can i write it so that : user clicks submit if the file already exists append to that file else create new file so far i've got : private void submitButton_Click (object sender, EventArgs e) { lNameTextBox_Validated(this, e); fNameTextBox_Validated(this, e); createNewPerson(); } private void createNewPerson() { using (StreamWriter sw = new StreamWriter(dataPath) if(File.Exists) //this shows error: cannot convert method group exists to non delegate type bool????? HELP! }

Vulpes · Answer

If you're using StreamWriter, the code would be something like this: using (StreamWriter sw = new StringWriter(@"c:	ext.txt")) { sw.WriteLine("Name = " + txtName.Text); sw.WriteLine("Address = " + txtAddress.Text); }

ICE QUEEN · Answer

Thanx, i decided to use the using statement of Stream writer ;) now i am stuck as to how i can actually implement this.... I have a windows based application form for a new employee, with the usual fields, Name, Address etc. After the user has filled in the form, i need to write (copy) that to a text file to SAVE the info... Any help will be MUCH APPRECIATED!!!!

Vulpes · Answer

The 'convenience' methods referred to in my previous post all close the file automatically when they're done so it's not an issue in practice. However, if you're use StreamReader or StreamWriter, then I agree that you need to be careful to close the file afterwards or utilize the 'using' statement instead which does it for you.

Terrance C · Answer

Be sure that you don't leave the file open. You might want to wrap your file operation statement up in a using clause. I like to use the following for file writing: using (StreamWriter sw = new StringWriter(filename,true)) { sw.WriteLine("Some text..."); sw.Flush(); } The using statement will make sure that your file is close successfully.

ICE QUEEN · Answer

ok, i figured it out by using the code in my last post & manually creating the text file it worked!

ICE QUEEN · Answer

but how do you create that text file initially? form the application or manually? i have been trying to use: string[] lines; if (File.Exists(@"c:	est.txt")) { lines = File.ReadAllLines(@"c:	est.txt"); foreach (string line in lines) { Console.WriteLine(line); } File.WriteAllLines(@"c:	est.txt", lines); } Console.Read(); } } } I dont get any errors but cant seem to find the file?????

Vulpes · Answer

Something like this perhaps: string userInput = textBox1.Text + "
" + textBox2.Text + "
" + textBox3.Text; System.IO.File.WriteAllText("somefile.txt", userInput);

c# writing user input from form to text file using windows a

Answers (51)