Reputation: 39364
I am reading all lines in a text file using C# 7 as follows:
using (StreamReader reader = File.OpenText(file)) {
String line;
while ((line = reader.ReadLine()) != null) {
}
}
For each line I also need to get the line number.
StreamReader does not seem to have a method for getting the line number.
What is the best way to do this?
Upvotes: 0
Views: 7975
Reputation: 76
I know this is already solved and old but I want to share an alternative. The code just returns the line number where it founds a part of the string given, to have the exact one just replace "Contains" with "Equals".
public int GetLineNumber(string lineToFind) {
int lineNum = 0;
string line;
System.IO.StreamReader file = new System.IO.StreamReader("c:\\test.txt");
while ((line = file.ReadLine()) != null) {
lineNum++;
if (line.Contains(lineToFind)) {
return lineNum;
}
}
file.Close();
return -1;
}
Upvotes: 0
Reputation: 1647
In addition to the other solutions here, I like to use File.ReadAllLines(string) to create a string[]
result and then for (int i = 0; i < result.Length; i++)...
.
Upvotes: 1
Reputation: 309
you can compute line number by your self:
using (StreamReader reader = File.OpenText(file)) {
String line;
int n = 0;
while ((line = reader.ReadLine()) != null) {
n++;
}
}
Upvotes: 0
Reputation: 14541
I'd just create an integer to keep track of the line number myself.
using (StreamReader reader = File.OpenText(file)) {
var lineNumber = 0;
String line;
while ((line = reader.ReadLine()) != null) {
...
lineNumber++;
}
}
Microsoft also uses such a variable to count the lines in one of the examples: https://learn.microsoft.com/en-us/dotnet/csharp/programming-guide/file-system/how-to-read-a-text-file-one-line-at-a-time
Upvotes: 4
Reputation: 1086
You should use your own local variable for it, like that:
using (StreamReader reader = File.OpenText(file)) {
String line;
int lineNum=0;
while ((line = reader.ReadLine()) != null) {
++lineNum;
}
}
Upvotes: 2