Develop Reference

Saving added items in a combobox to a file

I am having issues writing to a file in a C# program for class.
My program loads a .txt file to a combo box, which has 3 state options. Users can add up to 5 additional states from a selected list. On Exit, the program saves the added information back to the .txt file if the user chooses Yes.
My issue is that the code below is adding the default states back into the list. Should I be using an If statement under the foreach statement, or is there a way to write it so that only the User-added states are added to my .txt file and not all values all over again?
private void saveMyFile()
{
try
{
StreamWriter outputFile;
outputFile = File.AppendText("states.txt");
foreach (var cbitem in statesComboBox.Items)
{
outputFile.WriteLine(cbitem);
}
outputFile.Close();
MessageBox.Show("Your information has been saved. Closing program.");
}
catch
{
MessageBox.Show("Data could not be written to file");
}
}

There are several things you can do to achieve this.
If the order of the items in the combobox is fixed, you can skip the first x items when saving:
private int ExistingStates = 3; // You can later change this number when
// loading the items.
private void saveMyFile()
{
StreamWriter outputFile;
outputFile = File.AppendText("states.txt");
foreach (var cbItem in statesComboBox.Items.Cast<string>().Skip(ExistingStates))
{
outputFile.WriteLine(cbItem);
}
outputFile.Close();
}
You can have an array of the existing items so you can check if the item being saved already exists:
private string[] ExistingStates = {"state1", "state2"}; // Add items to the array
// after loading them.
private void saveMyFile()
{
StreamWriter outputFile;
outputFile = File.AppendText("states.txt");
foreach (var cbItem in statesComboBox.Items)
{
if (!ExistingStates.Contains(cbItem))
outputFile.WriteLine(cbItem);
}
outputFile.Close();
}
Another option is to overwrite the existing items by replacing the AppendText method with CreateText:
private void saveMyFile()
{
StreamWriter outputFile;
outputFile = File.CreateText("states.txt");
foreach (var cbItem in statesComboBox.Items)
{
outputFile.WriteLine(cbItem);
}
outputFile.Close();
}
Or you can replace the whole method with one simple line (using the WriteAllLines method):
File.WriteAllLines("states.txt", statesComboBox.Items.Cast<string>());
Hope that helps.

Replacing one specific line in a textfile in c# [duplicate]

This question already has an answer here:
Modify the content of specific line in text file
(1 answer)
Closed 8 years ago.
I'm having a textfile say something like this:
#TITLE:What's Up
#ARTIST:4 Non Blondes - Whats Up
#MP3:Four Non Blondes - Whats Up.mp3
#COVER:4 Non Blondes - Whats Up [CO].jpg
#BACKGROUND:4 Non Blondes - Whats Up [CO].jpg
#BPM:135
#GAP:32100
it's saved as 4 Non Blondes - Whats Up.txt
In the same folder there's a MP3 file which is in this example: 4 Non Blondes - Whats Up.mp3
What i want is to replace the line:
#MP3:Four Non Blondes - Whats Up.mp3
into this line:
#MP3:4 Non Blondes - Whats Up.mp3
Every MP3 line has infront of the line this:
#MP3:[Songname].mp3
I know i can do this manually but i have like 2k files like this, and they all need to link to the correct mp3 file. I'm trying this in C#, but without luck.
This is what i've tried so far:
private static void testMethod(string path)
{
var x = System.IO.Directory.GetDirectories(path);
foreach (var directory in x)
{
string[] mp3Files = System.IO.Directory.GetFiles(directory, "*.mp3");
string[] txtFiles = System.IO.Directory.GetFiles(directory, "*.txt");
string MP3FileNameWithExtensions = System.IO.Path.GetFileName(mp3Files[0]);
Console.WriteLine(txtFiles[0]);
var lines = System.IO.File.ReadAllLines(txtFiles[0]);
for (int i = 0; i < lines.Length; i++)
{
if(lines[i].Contains("#MP3")){
Console.WriteLine("Jeeeej working");
lines[i] = "#MP3:"+MP3FileNameWithExtensions;
System.IO.File.WriteAllLines(txtFiles[0], lines);
}
}
}
}

As the filename of the .txt file is [Songname].txt, you can use Path.GetFilenameWithoutExtension(files[i]) to get [Songname]. Then replace the #MP3 line with the filename + ".mp3". Now write out the file.
N.B. You will probably want to make a copy of the directory you are working on just in case something goes wrong.

I know I am late to the party but here is an example.
public void FixTheFiles(String startFolderPath)
{
foreach (String dirName in Directory.GetDirectories(startFolderPath))
{
FixTheFiles(dirName);
}
foreach (String fileName in Directory.GetFiles(startFolderPath))
{
FileInfo fi = new FileInfo(fileName);
if (fi.Extension.Equals("MP3"))
{
String fileContents = "";
using (StreamReader sr = new StreamReader(File.Open(fileName.Replace(".mp3",".txt"),FileMode.Open)))
{
String currentLine = sr.ReadLine();
if (currentLine.StartsWith("#MP3:"))
{
currentLine = "#MP3:" + fileName.Substring(fileName.LastIndexOf('\\')+1);
}
fileContents += currentLine;
}
using (StreamWriter sw = new StreamWriter(File.Open(fileName.Replace(".mp3",".txt"),FileMode.Open)))
{
sw.Write(fileContents);
}
}
}
}

I would simutaneously open a stream reader and a stream writer (with a different file name) and go through each file one line at a time searching for whatever changes you need to make. You can select your file names with an openfiledialog with Multiselect = true or run this command in a command prompt window to generate a textfile to paste in your code with quotation marks around them as initial values for a string array instantiation.
dir *.mp3 /b > filenames.txt
string[] array = new string[] {"file0.mp3",
"file1.mp3",
"file2.mp3",
"file3.mp3",
"file4.mp3",
"file5.mp3"};

To get selected list box value with folder path

I have a list box and its populated by this method,
private void ToReadFromExcel_Load(object sender, EventArgs e)
{
string folderpath = #"\\gibson\users";
// Call the method to show available files
PopulateListBox(ExcelListBox, folderpath, "*.csv");
}
// To populate list box with csv files from given path
private void PopulateListBox(ListBox lsb, string Folder, string FileType)
{
DirectoryInfo dinfo = new DirectoryInfo(Folder);
FileInfo[] Files = dinfo.GetFiles(FileType);
foreach (FileInfo file in Files)
{
lsb.Items.Add(file.Name);
}
}
String strItem;
foreach (Object selecteditem in ExcelListBox.SelectedItems)
{
strItem = selecteditem as String;
MessageBox.Show(strItem);
}
// read csv file information and insert into detail table
string filepath = #"\\gibson\users\CampManager.csv";
StreamReader sr = new StreamReader(filepath);
I hard coded the file path now, but I need to pass the filepath that was selected in the listbox. I have the file name in the variable stritem. If I want to pass the whole folder path how would I do that?

There is an ideal way. You should, instead of adding the FileInfo object's Name, should add the FileInfo object itself. So later you will be able to retrieve any piece of info related to that object, in your case say size, parent folder etc, and not just file name. Do it like this:
// To populate list box with csv files from given path
private void PopulateListBox(ListBox lsb, string Folder, string FileType)
{
DirectoryInfo dinfo = new DirectoryInfo(Folder);
FileInfo[] Files = dinfo.GetFiles(FileType);
foreach (FileInfo file in Files)
{
lsb.Items.Add(file); //<-- note here
}
}
String strItem;
foreach (FileInfo selecteditem in ExcelListBox.SelectedItems)
{
StreamReader sr = new StreamReader(selecteditem.FullName);
//or whatever
}
One thing you should take care of here is to set the DisplayMember property of the ListBox like this:
ExcelListBox.DisplayMember = "Name";
What this does is to set the what property of the object in the listbox should be displayed. So here you choose FileInfo.Name which is what you want. This is how typically custom objects are added to ListBoxes in WinForms. You do not add just the string part of it typically. Akin to DisplayMember, there is also ValueMember property which is used to assign a value for each object, probably some id or so, but in your case nothing.
Few suggestions, 1) If you're using .NET 4, then use EnumerateFiles instead of GetFiles. The former is lazy and only yields a result when you start enumerating them (not beforehand), so it should be faster.
foreach (FileInfo file in dinfo.EnumerateFiles(FileType)) //<-- note here
{
lsb.Items.Add(file);
}
2) Use a using clause to dispose your stream reader properly, since that wont lock your file. It's always a good practice to make use of using. Its better on eyes than manual closing and disposing! Like this or so:
foreach (FileInfo selecteditem in ExcelListBox.SelectedItems)
{
using(StreamReader sr = new StreamReader(selecteditem.FullName))
{
//your code here
}
}

add items properties - c# winform

I'd like to load the multiple files (like Images, Documents, Pdfs) to the listview and along its properties will be displayed.
This was the code I am working with:
FileInfo FInfo;
DialogResult dr = this.openFD.ShowDialog();
if (dr == System.Windows.Forms.DialogResult.OK)
{
// Read the files
foreach (String file in openFD.FileNames)
{
string fileName = Path.GetFileNameWithoutExtension(file);
ListViewItem item = new ListViewItem(fileName);
item.Tag = file;
listView1.Items.Add(item);
}
}
Please help me.

Here is the way I do for Excel files. You just need to modify it a bit. I am hoping this helps.
private void loadMatchingResponsesReports()
{
listBox2.Items.Clear();
string[] list = getMatchingReports();
foreach (String S in list)
{
FileInfo fileResponse = new FileInfo(S);
string fileResponseNameOnly = fileResponse.Name;
listBox2.Items.Add(fileResponseNameOnly);
GC.Collect();
}
}
public string[] getMatchingReports()
{
string[] returnR = null;
try
{
returnR = Directory.GetFiles(textBox3.Text + #"\", "*.xls");
}
catch
{
MessageBox.Show("Can't get some files from directory " + textBox3.Text);
}
return returnR;
}

Instead of a simple string, you might want to use a custom object to store all properties you want associated with the ListViewItem.
item.Tag = file;
file should be of custom type, a Dictionary<string, string> maybe.

You need to use the FileInfo class. For each file you want to add, construct an instance. It as has all the properties you would want to add to an explorer like interface such as: CreationTime, Extension, Name etc. You get the size (in bytes) from the Length property.
You would add a ListViewSubItem for each attribute, corresponding to the column in your ListView.

C# Using Lists to read, write and search text file lines

I need to perform the following operations with a text file and a List:
Read all lines of text file (non delimited) into a string based list
Whilst the application is open I need to do the following:
Check for instances of a string in the List
Add new entries to the List
Remove all identical instances of a defined string from the List
Write the contents of the List back to the text file including any changes made as soon as they are made
Firstly, how do I read and write between Lists and text files?
Secondly, how do I search a List for a string?
Lastly, how do I safely remove an item out of a List without leaving gaps in the text file I write?

public void homework()
{
string filePath = #"E:\test.txt";
string stringToAdd = "test_new";
IList readLines = new List();
// Read the file line-wise into List
using(var streamReader = new StreamReader(filePath, Encoding.Default))
{
while(!streamReader.EndOfStream)
{
readLines.Add(streamReader.ReadLine());
}
}
// If list contains stringToAdd then remove all its instances from the list; otherwise add stringToAdd to the list
if (readLines.Contains(stringToAdd))
{
readLines.Remove(stringToAdd);
}
else
{
readLines.Add(stringToAdd);
}
// Write the modified list to the file
using (var streamWriter = new StreamWriter(filePath, false, Encoding.Default))
{
foreach(string line in readLines)
{
streamWriter.WriteLine(line);
}
}
}
Try to google before you post the question.

I'd start here:
Read from text file: http://dotnetperls.com/readline
List Actions
1. Removing from a list
2. Searching in a List
Write to a text file: http://www.csharp-station.com/HowTo/ReadWriteTextFile.aspx

I'll just share my idea...
using System.IO;
public void newMethod()
{
//get path of the textfile
string textToEdit = #"D:\textfile.txt";
//read all lines of text
List<string> allLines = File.ReadAllLines(textToEdit).ToList();
//from Devendra's answer
if (allLines.Contains(stringToAdd))
{
allLines.Remove(stringToAdd);
}
else
{
allLines.Add(stringToAdd);
}
//extra: get index and edit
int i = allLines.FindIndex(stringToEdit => stringToEdit.Contains("need to edit")) ;
allLines[i] = "edit";
//save all lines
File.WriteAllLines(textToEdit, allLines.ToArray());
}