How to read a file whose address is stored in a variable.

Question

1.00/5 (1 vote)

See more:

C#

string text = System.IO.File.ReadAllText(@"D:\Selected Instances\Insertion graphs\1-FullIns_3.col");

this is the way to read a file what if we have file path stored on FileName variable.

What I have tried:

C#

string text = System.IO.File.ReadAllText(@FileName);

not working

Posted 14-May-16 17:49pm

Member 12404741

Updated 14-May-16 19:19pm

Patrice T

v3

Add a Solution

Comments

Garth J Lancaster 15-May-16 0:04am

'not working' doesnt mean much to us out here - since we cant see your screen, debugger, or read your mind. Frankly, I'd make sure your file exists before trying to read it - this string text = System.IO.File.ReadAllText(@"D:\Selected Instances\Insertion graphs\1-FullIns_3.col"); is fine if D:\Selected Instances\Insertion graphs\1-FullIns_3.col exists - text should then be a string with all the data from the file in it - you can split it or whatever ....

Sergey Alexandrovich Kryukov 15-May-16 0:19am

To start with, there are no situation where the hard-coded file path can be useful, unless this is done just for experiment/test...
—SA

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Garth J Lancaster · Accepted Answer · 2016-05-14T18:07:00

Solution 2

I'd think about

C#

string filename = @"D:\Selected Instances...";
if (!File.Exists(filename))
{
  Console.WriteLine("File {0} Doesnt Exist", filename);
  Environment.Exit(-1);
}

string text = File.ReadAllText(filename);

// Do something with text

Posted 14-May-16 18:07pm

Garth J Lancaster

Comments

Sergey Alexandrovich Kryukov 15-May-16 0:23am

Better, a 5. :-)
But more importantly, there are no situation where the hard-coded file path can be useful, unless this is done just for experiment/test...
—SA

George Jonsson · Accepted Answer · 2016-05-14T18:05:00

Solution 1

Have you tried

C#

string fileName = @"D:\Selected Instances\Insertion graphs\1-FullIns_3.col";
string text = System.IO.File.ReadAllText(fileName);

The @ character cannot be used with a variable, only literal strings.
See String Class (System)[^]

Quote:
Note that in C#, because the backslash (\) is an escape character, literal backslashes in a string must be escaped or the entire string must be @-quoted.

Posted 14-May-16 18:05pm

George Jonsson

Updated 14-May-16 18:06pm

v2

Comments

Sergey Alexandrovich Kryukov 15-May-16 0:22am

5ed. I was about to note that "The @ character cannot be used with a variable, only literal strings" sounds extremely weird, but later noticed that the weirdness is in the inquirer's sample. It's hard to explain the possible logic behind it. :-)

But more important, there are no situation where the hard-coded file path can be useful, unless this is done just for experiment/test...

—SA

George Jonsson 15-May-16 0:28am

Thanks Sergey.
Totally agree about the hard coded paths, but what to do in a short example code like this?
And for the weirdness of my comment about @, my only defense is that I'm not a native English speaker. :P

Garth J Lancaster 15-May-16 0:42am

your english is undoubtedly better than my Swedish (I know a few words) even less ?Ukrainian for Sergey. You're 'spot on' about the filename George - given no other input from the poster, its as much as one can do to promote a little 'sanity' ...

'skal' :-) (dont know how to get the accent via keyboard on a Mac)

George Jonsson 15-May-16 1:13am

Tack Garth.
I'm not a Mac user, but on Windows you can use the key combination Alt+390 to produce an 'å'. No idea what the equivalent is on a Mac.
Then it becomes 'skål'.
(A bit too early yet here in the Philippines for a beer, though)

Sergey Alexandrovich Kryukov 15-May-16 1:42am

Not Ukrainian, Russian. Who told you that. By the way, I started to understand a little more of Ukrainian after I started to watch some of Ukrainian TV via Youtube, which used to be very interesting at that time. Many understand it better then I am; it's a matter of some not very hard practice...

Our comparisons of knowledge of English is pretty much irrelevant... (I have no idea what George's native language might be, it's interesting...)

—SA

George Jonsson 15-May-16 1:53am

My mother tongue is Swedish, but you are right Sergey. It is pretty irrelevant in this forum. :)

Sergey Alexandrovich Kryukov 15-May-16 10:13am

Thank you, George. This is not what I meant to say. It's good to discuss some side topics sometimes; I like it. I did not express it clearly. I mean that the possible communication problems are unrelated to the present discussion. Please see also my comment below (long one).
—SA

Garth J Lancaster 15-May-16 2:09am

sorry - didnt mean to cause offence Sergey - just a guess hence the ? in front of it - I have some friends who used to say 'Russian' because they were tired of explaining that 'Russia' and 'Ukraine' are separate countries (these days) .. yes, our native languages are irrelevant (George's is Swedish), mine is gibberish (joke)

Sergey Alexandrovich Kryukov 15-May-16 10:10am

Come on, what "offense"? Not at all. This is not what I meant. I mean, we three don't have problem with language barriers, but a number of any other members do. And often the bigger problem is general communication problem, not language. (One of the biggest communication problems is laziness. :-)

So, as to those Ukrainian people who called themselves Russian. It happened all the time. Let me assure you: this is not because they "tired to explain", even if this is what they tell you so. They may not even realize why they really say so.

You see, in many societies, there are no such simple structures as "country", "ethnos", and the like. The concept of ethnos is complicated and... depends on context. There can be ethnos, sub-ethnos, and so on. The dominating theory of ethnic groups are... pretty poor, there are different views, so I think that scientists who are closer to deeper understanding of the subject are those who say that the dominating feature is how one characterized oneself. And here we see the different levels of ethnic relationship. It's not very wonderful that even the strong Ukrainian nationalist arguing that his people is "better", working in US call himself Russian, but not because he is "tired to explain", but because, in this context, he is really Russian. You see, in Ukraine, there are many people who consider then Russians, and some people deny it, and it poorly correlated with the official government document data. Many consider Ukrainian language as a Russian dialect (but I have trouble to understand it :-), many don't want to hear about that, but there are many Ukraine dialects, very different, while Russian dialects are extremely close except... Russian dialects in Ukraine and southern Russia close to Ukraine.

It's interesting that on Ukrainian TV nearly all speak very good and clear Russian. I mean, the official narrator behind the scene always dictate the text in "official" Ukrainian, but when, say, the guests come into studio, they all talk in good Russian. Some people prefer Ukrainian, usually their own dialect, and then the host easily switches to Ukrainian. This way, they all keep conversation using the mix of languages, but Russian strongly dominates.

Even people who consider themselves Ukrainian and no way Russian, really think of themselves as Russian when they live abroad. It's more than names. We go to the Russian shops and meet many Russian people there, but very few are ethnic Russians, because Russian migration was always very low. Most of the proprietors, workers of the shop are people of the ethnic groups such as Ukrainian, Jewish, Tatar, and... who not... the proportions are radically different from that in Russia. But they all consider themselves Russians and really think of themselves as Russian in that context, because it is our super-group. We really have too much in common. It has nothing to do with language; the native languages are not always Slavic, they are also Turkic, other Altaic, Ugric, Iranian, and a lot more, even if I mention a big language families (not groups). Some ethnic groups view themselves as of Russians very much, some don't feel this way at all.

—SA

Sergey Alexandrovich Kryukov 15-May-16 1:36am

I'm also not a native speaker.
There is no need to show @"D:/...", because the inquirer did not make a mistake in it.
I usually write something like
string fileName = // ...

It would be enough to say that @ before the name is... who knows what.

—SA

Member 12404741 15-May-16 2:50am

thanks to all