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How to reference files via a relative path within the C# application????? RRS feed

  • Question

  • Hello,

    I have a C# Windows Form application. In one of my cases, I am opening a config file like this:

    string ctryConfig = "c:/visual_studio_projects/config/iso_3166.xml";
    XmlDocument doc = new XmlDocument();
    doc.Load(ctryConfig);

    This works as long as I run the app on my computer. I want to put the xml file within a directory in my C# project and then reference the file as a relative path, such as:

    string ctryConfig = "../config/iso_3166.xml";

    This way I can create a separate directory in my app for config files, images, etc.

    I can't find a way to reference the location of these files with a relative path within the application context.

    Any thoughts would be greatly appreciated.

    Thanks - Peter
    Friday, August 20, 2010 6:21 PM

Answers

  • Mike,

    That's not his problem in this case, but good to point out for him none the less.

    Peter,

    You're thinking way too hard. You have mixed up Resources in Applications, which are usually embedded in an assembly, with loose files your application can load at runtime using a relative path. I think I understood how you get here, hence another post.

    Let me try to summarize these two issues one last time for you:

    First, you were adding an extra "/" to the beginning of your relative path for a loose file and this will break your path as I've laid out in much detail in my previous posts.

    Last, you assumed the project's resource file (RESX) contents were needed in your application's runtime directory (such as the ones created/used when you add an Image to a PictureBox). Not true, and this is why those "worked" when you moved the app to a different directory (b.c. they were embedded in the EXE itself and not dependant on the directory structure).

    Obviously, how a RESX file works is a much more complicated discussion (I'll save that for later but it's homework for you). A resx contains its resources and can be embedded in an assembly. This is typically how WinForms resx files are compiled (and the easiest way to work with them) and you have already seen how they work. For more information, read the above link for Resources in Applications. 

    Here is a picture showing you how a Form's RESX file is configured to be embedded:

    resx

    If you load an image into a picture box and choose "Local Resource" it goes to your Form's resx file as shown in the image above. Otherwise, it can go to a different resx in the project but that creates a folder "Resources" when it imports the file (image in your example). This "imported resource" is compiled into the resx and is not deployed with the application in production (b.c. the resx gets embedded in the application).

    Hopefully, your head isn't spinning.

    -Scosby

    Wednesday, August 25, 2010 6:12 AM

All replies

  • i guess relative path will work. just keep it in normal way.

    ~/ for root and then after make your path to the file


    Regards Kumar Gaurav. Please Mark as an answer in case the post is helpful to you so that it became helpful to others
    • Proposed as answer by Viking28 Wednesday, May 22, 2013 4:07 PM
    Friday, August 20, 2010 6:26 PM
  • Inno,

     

    Thanks for the reply.  I am not sure I understand though.  If I try to decalre the path like:

    string

     

    ctryConfig = "~/Resources/config/iso_3166.xml";

    or

    string

     

    ctryConfig = "/Resources/config/iso_3166.xml";

    I get an error that the path cannot be found.  I am creating and running my app via Visual Studio 2008.  With the first example, the relative path is just added to the full execution path (c:\.....\bin\Debug\~\Resources....).  With the second example, it is looking for that path from the c:\ drive.

    Either I misunderstand your response or I need to do something else for this environment.

    Friday, August 20, 2010 6:52 PM
  • Hi Peter,

    You could use the Application.StartupPath property to resolve the relative paths into full paths. Else, you should be able to leave off any leading slashes and it will look in the application's root directory.

        static public void CheckRelativeFilePath()
        {
          //This folder path is %project directory%/bin/debug/test/img.bmp
          bool exists = File.Exists("test/img.bmp");
        }
    

    Good luck!

    -Scosby

    Friday, August 20, 2010 6:58 PM
  • Scosby,

    Yes, if I use a relative path based on the PROJECT_HOME/bin/Debug directory, then I can declare it like:

    string

     

    ctryConfig = "../../Resources/config/iso_3166.xml";

    That works.  My question now is whether the application will typically always be started from the bin/Debug directory so that type of relative path starting point will be accurate. 

    Thanks - Peter

    Friday, August 20, 2010 7:39 PM
  • That depends on how you want your application to be setup.  Generally it is one of the responsibilities of an installation program to place files in the location where they are expected relative to the executable file.
    Friday, August 20, 2010 7:56 PM
  • Hi Peter,

    You don't need anything to start your path with other than the relative folder. Look at how I referenced my path in the example I previously gave you, I just specified the subfolder in the application's directory.

    Think of this another way, if you were going to open a file in the same directory as your application you'd just specify the file name. Your relative path scenario is very similar, start by just specifying the folder name. Here is an example of what you should be doing:

    string ctryConfig = "../../Resources/config/iso_3166.xml"; //wrong - this says, go 2 directories up<br/>
    string relativePath = "Resources/config/iso_3166.xml"; //correct - looks in the application directory
    

    HTH

    -Scosby

    Friday, August 20, 2010 7:57 PM
  • Scosby, your change would only work if there was a resources folder within the bin directory with a config folder and then an xm file within that.  The OP has clearly added a folder to his projects root directory, and relative paths are specified not from the project's root directory, but from the executable's location (unless you specifically change the working directory).
    Friday, August 20, 2010 8:09 PM
  • I must be misunderstanding you s3rvy. I said the application's directory, which means whatever directory the .EXE is located in. I did NOT say the project's directory and my example clearly showed the folder I was using for reference. In fact, I further clarified the post by saying "if you were going to open a file in the same directory as your application..." and explained what the path strings were doing.

    The op has said nothing about placing the application .EXE in a subfolder, only his resources. But you are correct s3rvy, if the OP would place his .EXE in a nested folder then he would need to navigate back up the directory tree to his "resources" directory in his relative file path.

    The OP's problem is that he is specifying a leading slash on his path or navigating up and away from the application directory. He's not listening to my advice already given to ignore those extra directory seperators. The leading slash will effectively say "go to the root directory of the drive". Here is a snippet to prove it once and for all:

          string path1 = Path.GetFullPath("/test/img.bmp");
    
          string path2 = Path.GetFullPath("test/img.bmp");
    

    path1 will be "c:\test\img.bmp" and this is WRONG.

    path2 will be "c:\<Application.StartupPath>\test\img.bmp" and this is CORRECT. As long as the EXE is in the Application.StartupPath, but the OP hasn't indicated this yet.

    -Scosby

    • Proposed as answer by Scosby Saturday, August 21, 2010 1:36 AM
    Friday, August 20, 2010 8:39 PM
  • Scosby, he's clearly developing the program in Visual Studio, which, by default, will put the executable in the <projectpath>/bin/debug folder.  The file he wishes to access is in the <projectpath>/Resources/config/ folder.  The working directory, by default, is the location of the executable, not the root folder of the project created by visual studio; as such the solution is either to use what he did above to to up to levels and then back down, or to move the file(s) that you wish to access to locations relative to the executable's path, i.e. move the resources folder to the /bin/debug directory (or move the executable to the root directory of the project).  All of those can be altered using the compile tab of the project properties, if you're interested.
    Friday, August 20, 2010 9:12 PM
  • ctryConfig = "/Resources/config/iso_3166.xml";

    ...With the second example, it is looking for that path from the c:\ drive.

    Peter, the solution is to remove the leading slash. It should just start with "Resources".

    -Scosby

    Saturday, August 21, 2010 1:40 AM
  • There seems to have ben quite a discussion here.  In my original post, I made some assumptions and probably did not fully explain it.  As per one of the comments, I am using Visual Studio and by default, the EXE is located in the bin/Debug folder.  I am new to C# (I am a Java guy) and don't know what some of the standard practices are, but I would never envision putting sub-directories (for config files, images, etc) inside a bin directory.  My thought all along was to add new directories from the application root, which is not the executable root and is why I had to go up two directories first (ie ../../Resources/config....). 

    I guess as long as I realize where the EXE file is located within the app, I should be fine making a relative path from there.

     

    Thanks - Peter

    Monday, August 23, 2010 11:47 AM
  • If you put your folders inside the project directory instead of inside the bin\Debug, you need to go two directories up. That means that if you install your app in c:\Program Files\MyApp, you'll need to put your folders at the root of c:
    Monday, August 23, 2010 12:15 PM
  • Yeah, now I am a little more confused, which I will chalk up to my lack of C# Windows Forms application experience.  When I am in my Visual Studio project bubble, all was well when I used a relative path from by bin/Debug directory (where the EXE file is located).  If I take that EXE and move it to some other directory and execute it, my relative path is broken because I did not bring over the directory structure with my config file.  I can see why this is happening and that is okay. 

    Now, however, I am trying to understand how references to other files added via Visual Studio are not broken.  For example, I have a PictureBox control in which I add the image in the Visual Studio Image property for that control and use "Project resource file".  This apparently makes a copy of whatever file I choose and puts it in the <project_home>/Resources directory and also adds it to the .resx file.  After compiling the app, I can take the EXE file and execute if from anywhere and the image will be displayed.  The Resources.resx file is located in the <project_home>/Properties directory and it contains a reference to the image as ../Resources/image.jpg.  That is obviously a relative path from the Properties directory.  It looks like when Visual Studio compiles the app, it includes all that it knows about the app with the EXE file (ie it knew about that image because I added it through Visual Studio).  Anything added separately (like I did when I added my own subdirectory) it does not know about and won't add to the EXE file.

    I guess this could be another whole thread on what gets embedded in the EXE and what doesn't.

     

    Thanks - Peter

    Monday, August 23, 2010 12:43 PM
  • Hi Peter Len,

     

    Welcome to MSDN Forum!

     

    This image will tell you how to solve your question.

     

    1.       Add the folder and the files through the Solution Explorer

    2.       Click on the file(in this, click on the iso_3166.xml)

    3.       Then you can change the property to let the .xml file appear in the output directory, in other words, it is appear in the application directory, and you can use this file through a simple relative path.

     

     

    If there’s anything unclear please let me know, and I’d glad to help you.

     

    Have a nice day!

    Mike

    -------------------------------------------------------------------

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    • Proposed as answer by imadoki Thursday, June 28, 2012 6:37 PM
    Tuesday, August 24, 2010 6:04 AM
    Moderator
  • Mike,

    That's not his problem in this case, but good to point out for him none the less.

    Peter,

    You're thinking way too hard. You have mixed up Resources in Applications, which are usually embedded in an assembly, with loose files your application can load at runtime using a relative path. I think I understood how you get here, hence another post.

    Let me try to summarize these two issues one last time for you:

    First, you were adding an extra "/" to the beginning of your relative path for a loose file and this will break your path as I've laid out in much detail in my previous posts.

    Last, you assumed the project's resource file (RESX) contents were needed in your application's runtime directory (such as the ones created/used when you add an Image to a PictureBox). Not true, and this is why those "worked" when you moved the app to a different directory (b.c. they were embedded in the EXE itself and not dependant on the directory structure).

    Obviously, how a RESX file works is a much more complicated discussion (I'll save that for later but it's homework for you). A resx contains its resources and can be embedded in an assembly. This is typically how WinForms resx files are compiled (and the easiest way to work with them) and you have already seen how they work. For more information, read the above link for Resources in Applications. 

    Here is a picture showing you how a Form's RESX file is configured to be embedded:

    resx

    If you load an image into a picture box and choose "Local Resource" it goes to your Form's resx file as shown in the image above. Otherwise, it can go to a different resx in the project but that creates a folder "Resources" when it imports the file (image in your example). This "imported resource" is compiled into the resx and is not deployed with the application in production (b.c. the resx gets embedded in the application).

    Hopefully, your head isn't spinning.

    -Scosby

    Wednesday, August 25, 2010 6:12 AM
  • It works for me!!

     

    Thank you

     

    T.

    Monday, May 23, 2011 5:58 AM
  • does root mean root of the project, or solution?
    Friday, February 23, 2018 7:10 PM