How to use textfieldParser to edit CSV file?
I wrote a small function that reads a csv file using textField, line by line, edit it in a specific field, and write it back to the 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 change is 12th (parts [12]):
for example : if parts[12] = 000,000,234 then change to 000
the file is created, the problem is that it does not edit the file and half of the records are missing. I hope someone can point out the error.
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You call both parser.ReadFields()
and parser.ReadLine()
. Each of them moves the cursor one by one. This is why you are missing half the lines. Change while
to:
while(!parser.EndOfData)
Then add parts = parser.ReadFields();
to the end of the loop. Without it, why you are editing is not visible.
You can also remove:
if (parts == null)
{
break;
}
Since you no longer have line
, you will need to use fields to track your results:
lines.Add(string.Join(",", parts));//handle string escaping fields if needed.
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