I wrote a small function that reads a csv file using textField line by line , edit it a specific field then write it back to a CSV file.
Here is the code :
private void button2_Click(object sender, EventArgs e)
{
String path = #"C:\file.csv";
String dpath = #"C:\file_processed.csv";
List<String> lines = new List<String>();
if (File.Exists(path))
{
using (TextFieldParser parser = new TextFieldParser(path))
{
String line;
parser.HasFieldsEnclosedInQuotes = true;
parser.Delimiters = new string[] { "," };
while ((line = parser.ReadLine()) != null)
{
string[] parts = parser.ReadFields();
if (parts == null)
{
break;
}
if ((parts[12] != "") && (parts[12] != "0"))
{
parts[12] = parts[12].Substring(0, 3);
//MessageBox.Show(parts[12]);
}
lines.Add(line);
}
}
using (StreamWriter writer = new StreamWriter(dpath, false))
{
foreach (String line in lines)
writer.WriteLine(line);
}
MessageBox.Show("CSV file successfully processed ! ");
}
}
The field I want to edit is the 12th one (parts[12]):
for example : if parts[12] = 000,000,234 then change to 000
the file is created the problem is it does not edit the file and half the records are missing. I am hoping someone could point the mistake.
You call both parser.ReadFields() and parser.ReadLine(). Each of them advance the cursor by one. That's why you're missing half the rows. Change the while to:
while(!parser.EndOfData)
Then add parts = parser.ReadFields(); to the end of the loop. Not having this is why you're edit isn't being seen.
You can also remove:
if (parts == null)
{
break;
}
Since you no longer have line, you'll need to use the fields to keep track of your results:
lines.Add(string.Join(",", parts));//handle string escaping fields if needed.
Related
I have a code which iterates through the entire text file searching for a specific text "[names]", and "tried" to delete all the lines below the text. I tried File.WriteAllText(INILoc, string.Empty);, but this just deletes everything in the entire text file. How do I make it so only all the lines below "[names]" gets deleted?
I have set up the iteration likes this :
string[] lines = File.ReadAllLines(INILoc);
bool containsSearchResul = false;
foreach (string line in lines)
{
if (containsSearchResul)
{
File.WriteAllText(INILoc, string.Empty);
}
if (line.Contains("[names]"))
{
containsSearchResul = true;
}
}
You need to store lines before "[names]" text into a string variable, and when condition (line.Contains("[names]")) satisfy then just break the loop and write string value into the same file.
Something like,
string[] lines = File.ReadAllLines(INILoc); //Considering INILoc is a string variable which contains file path.
StringBuilder newText = new StringBuilder();
bool containsSearchResul = false;
foreach (string line in lines)
{
newText.Append(line);
newText.Append(Environment.NewLine); //This will add \n after each line so all lines will be well formatted
//Adding line into newText before if condition check will add "name" into file
if (line.Contains("[names]"))
break;
}
File.WriteAllText(INILoc, newText.ToString());
//^^^^^^^ due to string.Empty it was storing empty string into file.
Note: If you are using StringBuilder class, then do not miss to add Using System.Text in your program
Use StreamReader as it will give you the best performance as you don't need to read the whole file. Swap 'PATH TO INPUT FILE' with your file path and the result will be stored at the path you provide for 'PATH TO OUTPUT FILE'.
using (var sr = new StreamReader("PATH TO INPUT FILE"))
{
using (var sw = new StreamWriter("PATH TO OUTPUT FILE"))
{
var line = sr.ReadLine();
while (line != null)
{
sw.WriteLine(line);
if (line.Contains("[names]"))
{
sw.Close();
sr.Close();
}
else
{
line = sr.ReadLine();
}
}
}
}
If you need to write to the same file:
var sb = new StringBuilder();
using (var sr = new StreamReader("PATH TO INPUT FILE"))
{
var line = sr.ReadLine();
while (line != null)
{
sb.AppendLine(line);
if (line.Contains("[names]"))
{
sr.Close();
}
else
{
line = sr.ReadLine();
}
}
}
File.WriteAllText("PATH TO INPUT FILE", sb.ToString());
Based on the requested code I have put together modifications.
string[] lines = File.ReadAllLines(INILoc);
//create a list to hold the lines
List<string> output = new List<string>();
//loop through each line
foreach (string line in lines)
{
//add current line to ouput.
output.Add(line);
//check to see if our line includes the searched text;
if (line.Contains("[names]"))
{
//output to the file and then exit loop causing all lines below this
//one to be skipped
File.WriteAllText(INILoc, output.ToArray());
break;
}
}
The problem with your code is that it delete all the lines before the [names], not after (more exactly, write only the lines after that text). Also, any time you rewrite all the file content, and so remove all previous wrote line. It'll work as follows:
string[] lines = File.ReadAllLines(INILoc);
using (StreamWriter writer = new StreamWriter(INILoc)) // https://learn.microsoft.com/en-us/dotnet/standard/io/how-to-write-text-to-a-file
{
bool containsSearchResul = false;
foreach (string line in lines)
{
if (!containsSearchResul)
{
writer.Write(INILoc, string.Empty);
}
if (line.Contains("[names]"))
{
containsSearchResul = true;
}
}
}
You have another, better option to do this with break:
string[] lines = File.ReadAllLines(INILoc);
using (StreamWriter writer = new StreamWriter(INILoc)) // https://learn.microsoft.com/en-us/dotnet/standard/io/how-to-write-text-to-a-file
{
foreach (string line in lines)
{
if (line.Contains("[names]"))
{
break;
}
writer.WriteLine(INILoc, string.Empty);
}
}
But you can do this in prefered, more-readable way, by using LINQ:
using System.Linq;
// ...
string[] lines = File.ReadAllLines(INILoc);
string[] linesTillNames = lines
.Take( // Take just N items from the array
Array.IndexOf(lines, "[names]") // Until the index of [names]
)
.ToArray();
File.WriteAllLines(INILoc, linesTillNames);
You can also use: WriteAllLines(string path, IEnumerable<string> contents) like this:
string[] lines = File.ReadAllLines(INILoc);
List<string> linesToWrite = new List<string>();
foreach(string line in lines)
{
linesToWrite.Add(line);
if (line.Contains("[names]")) break;
}
File.WriteAllLines(INILoc, linesToWrite);
I'm currently using the below code to compare two csv files with each other. I can select a column in the file and it will compare the rows in that column, it then writes the incorrect and correct rows into another csv file. But now I want to change the color the text 'this row is not the same' so that it's more noticeable. How can I do this?
public void comparing(int selectedRow, string filenaname, string filename2)
{
List<string> lines = new List<string>();
List<string> lines2 = new List<string>();
try
{
StreamReader reader = new StreamReader(System.IO.File.OpenRead(filename));
StreamReader read = new StreamReader(System.IO.File.OpenRead(filename2));
List<string> lijnen = new List<string>();
string line;
string line2;
string differencesFile= #"C:\Users\Mylan\Desktop\differences.csv";
while ((line = reader.ReadLine()) != null && (line2 = read.ReadLine()) != null)
{
string[] split = line.Split(Convert.ToChar(csvSeperator));
string[] split2 = line2.Split(Convert.ToChar(csvSeperator));
if (split[selectedRow] != split2[selectedRow])
{
lijnen.Add("This row is not the same:, " + line);
}
else if(test == test2)
{
System.Windows.Forms.MessageBox.Show("The whole file is the same");
break;
}
else
{
lines.Add("This row is the same:, " + line);
}
}
System.IO.File.WriteAllLines(differencesFile, lines);
System.Diagnostics.Process.Start(differencesFile);
reader.Dispose();
read.Dispose();
}
catch
{
}
}
}
}
I think it's impossible to do what you want with CSV files. Excel reads only the values and separate these in columns, that's all.
If you want to create an Excel file directly by code, you need to use for example the Open XML :
https://msdn.microsoft.com/en-gb/library/office/bb448854.aspx
This is what I use to create, edit Excel files (and Powerpoint files too). It's a bit tricky at beginning but it's a solution...
I am trying to replace a specific data field in my csv file but am having issues.
My csv file is structured like:
user, password, role, id,
1, abc, 2, 3
2, def, 2, 4
3, ghi, 5, 5
I can read the file fine but when I want to replace a password using a textbox and button in a windows form I am having issues.
private void resetBtn_Click(object sender, EventArgs e)
{
var encoding = Encoding.GetEncoding("iso-8859-1");
var csvLines = File.ReadAllLines("C:\\Users\\hughesa3\\Desktop\\test environment\\users.csv", encoding);
foreach (var line in csvLines)
{
var values = line.Split(',');
if (values[0].Contains(form2value))
{
values[1] = confirmPass.Text;
}
}
}
Form2value is their username, So what im trying do is: If the first column contains what was entered in form2value it will go to the 2nd column of that row.
I have tried this
var values = line.Split(',');
if (values[0].Contains(form2value))
{
MessageBox.Show(values[1]);
values[1] = confirmPass.Text;
MessageBox.Show(values[1]);
}
}
Just to see if the value is changing and it is but it is also displaying every value[1] when i only want it to if form2value was found.
I tried to explain this as best as I could but if anyone needs more info please let me know.
Does anybody know what I am doing wrong ?
Life would be easier for you if you used a data table..........
Here is an excerp...
DT is a DataTable.
Split the first line of your file and us dt.Columns.Add to add the column headings....
private void AddDataToDataTable()
{
using (StreamReader sr = new StreamReader(new MemoryStream(this.FileContents)))
{
//Igone headings & blank Lines
string line = string.Empty;
while ((line = sr.ReadLine()) != null)
{
//If blank line then skip line
if (line == string.Empty)
{
continue;
}
dt.Rows.Add(line.Split(this.Delimeter));
}
}
}
Hope this helps
You're changing the values internal array you use in your code, not the file itself. In fact you're not writing the file anywhere, just reading it.
You'll need to: Read the file, get the line where the username is (if it exists), then write that specific line with the password.
Here's how you can do it:
private void resetBtn_Click(object sender, EventArgs e)
{
var encoding = Encoding.GetEncoding("iso-8859-1");
var csvLines = File.ReadAllLines("C:\\Users\\hughesa3\\Desktop\\test environment\\users.csv", encoding);
for (int i = 0; i < csvLines.Length; i++)
{
var values = csvLines[i].Split(',');
if (values[0].Contains(form2value))
{
values[1] = confirmPass.Text;
using (FileStream stream = new FileStream("C:\\Users\\hughesa3\\Desktop\\test environment\\users.csv", FileMode.Create))
{
using (StreamWriter writer = new StreamWriter(stream, encoding))
{
for (int currentLine = 0; currentLine < csvLines.Length; ++currentLine)
{
if (currentLine == i)
{
writer.WriteLine(string.Join(",", values));
}
else
{
writer.WriteLine(csvLines[i]);
}
}
writer.Close();
}
stream.Close();
}
}
}
}
I need to check certain columns of data to make sure there are no trailing blank spaces. At first thought I thought it would be very easy, but after attempting to achieve the goal I have got stuck.
I know that there should be 6-digits in the column I need to check. If there is less I will reject, if there are more I will trim the blank spaces. After doing that for the entire file, I want to write it back to the file with the same delimiters.
This is my attempt:
Everything seems to be working correctly except for writing the file.
if (File.Exists(filename))
{
using (StreamReader sr = new StreamReader(filename))
{
string lines = sr.ReadLine();
string[] delimit = lines.Split('|');
while (delimit[count] != "COLUMN_DATA_TO_CHANGE")
{
count++;
}
string[] allLines = File.ReadAllLines(#filename);
foreach(string nextLine in allLines.Skip(1)){
string[] tempLine = nextLine.Split('|');
if (tempLine[count].Length == 6)
{
checkColumn(tempLine);
writeFile(tempLine);
}
else if (tempLine[count].Length > 6)
{
tempLine[count] = tempLine[count].Trim();
checkColumn(tempLine);
}
else
{
throw new Exception("Not enough numbers");
}
}
}
}
}
public static void checkColumn(string[] str)
{
for (int i = 0; i < str[count].Length; i++)
{
char[] c = str[count].ToCharArray();
if (!Char.IsDigit(c[i]))
{
throw new Exception("A non-digit is contained in data");
}
}
}
public static void writeFile(string[] str)
{
string temp;
using (StreamWriter sw = new StreamWriter(filename+ "_tmp", false))
{
StringBuilder builder = new StringBuilder();
bool firstColumn = true;
foreach (string value in str)
{
if (!firstColumn)
{
builder.Append('|');
}
if (value.IndexOfAny(new char[] { '"', ',' }) != -1)
{
builder.AppendFormat("\"{0}\"", value.Replace("\"", "\"\""));
}
else
{
builder.Append(value);
}
firstColumn = false;
}
temp = builder.ToString();
sw.WriteLine(temp);
}
}
If there is a better way to go about this, I would love to hear it. Thank you for looking at the question.
edit:
file structure-
country| firstname| lastname| uniqueID (column I am checking)| address| etc
USA|John|Doe|123456 |5 main street|
notice the blank space after the 6
var oldLines = File.ReadAllLines(filePath):
var newLines = oldLines.Select(FixLine).ToArray();
File.WriteAllLines(filePath, newLines);
string FixLine(string oldLine)
{
string fixedLine = ....
return fixedLine;
}
The main problem with writing the file is that you're opening the output file for each output line, and you're opening it with append=false, which causes the file to be overwritten every time. A better approach would be to open the output file one time (probably right after validating the input file header).
Another problem is that you're opening the input file a second time with .ReadAllLines(). It would be better to read the existing file one line at a time in a loop.
Consider this modification:
using (StreamWriter sw = new StreamWriter(filename+ "_tmp", false))
{
string nextLine;
while ((nextLine = sr.ReadLine()) != null)
{
string[] tempLine = nextLine.Split('|');
...
writeFile(sw, tempLine);
I am trying to parse a CSV file with data with no luck, i have tried a bunch of tools online and none has been able to parse the CSV file correctly. I am baffled by the fact that i am in here asking for help as one would think parsing CSV data would be something super easy.
The format of the CSV data is like this:
",95,54070,3635,""Test Reservation"",0,102,0.00,0.00,2014-12-31,""Name of customer"",""$12.34 + $10, special price"",""extra information"",,CustomerName,,,,,1234567890,youremail#domain.com,CustomerName,2014-12-31,23:59:59,16,0,60,2,120,0,NULL,NULL,NULL,"
Current code:
private void btnOpenFileDialog_Click(object sender, EventArgs e)
{
DialogResult result = openFileDialog1.ShowDialog();
if (result == DialogResult.OK)
{
using (StreamReader reader = new StreamReader(openFileDialog1.FileName))
{
string line;
while ((line = reader.ReadLine()) != null)
{
ParseCsvLine(line);
}
}
}
}
private void ParseCsvLine(string line)
{
if (line != string.Empty)
{
string[] result;
using (var csvParser = new TextFieldParser(new StringReader(line)))
{
csvParser.Delimiters = new string[] { "," };
result = csvParser.ReadFields();
}
foreach (var item in result)
{
Console.WriteLine(item + Environment.NewLine);
}
}
}
The result variable only has one item and its:
,95,54070,3635,"Test Reservation",0,102,0.00,0.00,2014-12-31,"Name of customer","$12.34 + $10, special price","extra information",,CustomerName,,,,,1234567890,youremail#domain.com,CustomerName,2014-12-31,23:59:59,16,0,60,2,120,0,NULL,NULL,NULL,
// Add Microsoft.VisualBasic.dll to References.
using Microsoft.VisualBasic.FileIO;
// input is your original line from csv.
// Remove starting and ending quotes.
input = input.Remove(0, 1);
input = input.Remove(input.Length - 1);
// Replace double quotes with single quotes.
input = input.Replace("\"\"", "\"");
string[] result;
using (var csvParser = new TextFieldParser(new StringReader(input)))
{
csvParser.Delimiters = new string[] { "," };
result = csvParser.ReadFields();
}
You can check out a previous post that deals with those pesky commas in csv files. I'm linking it here.
Also Mihai, your solution works well for just the one line but will fail once there are many lines to parse.