How to read embedded resource text file

Question

How do I read an embedded resource (text file) using StreamReader and return it as a string? My current script uses a Windows form and textbox that allows the user to find and replace text in a text file that is not embedded.

private void button1_Click(object sender, EventArgs e)
{
    StringCollection strValuesToSearch = new StringCollection();
    strValuesToSearch.Add("Apple");
    string stringToReplace;
    stringToReplace = textBox1.Text;
    StreamReader FileReader = new StreamReader(@"C:\MyFile.txt");
    string FileContents;
    FileContents = FileReader.ReadToEnd();
    FileReader.Close();
    foreach (string s in strValuesToSearch)
    {
        if (FileContents.Contains(s))
            FileContents = FileContents.Replace(s, stringToReplace);
    }
    StreamWriter FileWriter = new StreamWriter(@"MyFile.txt");
    FileWriter.Write(FileContents);
    FileWriter.Close();
}

Solution 1

You can use the Assembly.GetManifestResourceStream Method:

1. Add the following usings

   using System.IO;
   using System.Reflection;
   

2. Set property of relevant file:
   Parameter Build Action with value Embedded Resource

3. Use the following code

   var assembly = Assembly.GetExecutingAssembly();
   var resourceName = "MyCompany.MyProduct.MyFile.txt";
   using (Stream stream = assembly.GetManifestResourceStream(resourceName))
   using (StreamReader reader = new StreamReader(stream))
   {
       string result = reader.ReadToEnd();
   }
   

   resourceName is the name of one of the resources embedded in assembly. For example, if you embed a text file named "MyFile.txt" that is placed in the root of a project with default namespace "MyCompany.MyProduct", then resourceName is "MyCompany.MyProduct.MyFile.txt". You can get a list of all resources in an assembly using the Assembly.GetManifestResourceNames Method.

---

A no brainer astute to get the resourceName from the file name only (by pass the namespace stuff):

string resourceName = assembly.GetManifestResourceNames()
  .Single(str => str.EndsWith("YourFileName.txt"));

---

A complete example:

public string ReadResource(string name)
{
    // Determine path
    var assembly = Assembly.GetExecutingAssembly();
    string resourcePath = name;
    // Format: "{Namespace}.{Folder}.{filename}.{Extension}"
    if (!name.StartsWith(nameof(SignificantDrawerCompiler)))
    {
        resourcePath = assembly.GetManifestResourceNames()
            .Single(str => str.EndsWith(name));
    }
    using (Stream stream = assembly.GetManifestResourceStream(resourcePath))
    using (StreamReader reader = new StreamReader(stream))
    {
        return reader.ReadToEnd();
    }
}

Solution 2

You can add a file as a resource using two separate methods.

The C# code required to access the file is different, depending on the method used to add the file in the first place.

Method 1: Add existing file, set property to Embedded Resource

Add the file to your project, then set the type to Embedded Resource.

NOTE: If you add the file using this method, you can use GetManifestResourceStream to access it (see answer from @dtb).

Method 2: Add file to Resources.resx

Open up the Resources.resx file, use the dropdown box to add the file, set Access Modifier to public.

NOTE: If you add the file using this method, you can use Properties.Resources to access it (see answer from @Night Walker).

Solution 3

Basically, you use System.Reflection to get a reference to the current Assembly. Then, you use GetManifestResourceStream().

Example, from the page I posted:

Note: need to add using System.Reflection; for this to work

   Assembly _assembly;
   StreamReader _textStreamReader;
   try
   {
      _assembly = Assembly.GetExecutingAssembly();
      _textStreamReader = new StreamReader(_assembly.GetManifestResourceStream("MyNamespace.MyTextFile.txt"));
   }
   catch
   {
      MessageBox.Show("Error accessing resources!");
   }

Solution 4

In Visual Studio you can directly embed access to a file resource via the Resources tab of the Project properties ("Analytics" in this example).

The resulting file can then be accessed as a byte array by

byte[] jsonSecrets = GoogleAnalyticsExtractor.Properties.Resources.client_secrets_reporter;

Should you need it as a stream, then ( from https://stackoverflow.com/a/4736185/432976 )

Stream stream = new MemoryStream(jsonSecrets)

Solution 5

When you added the file to the resources, you should select its Access Modifiers as public than you can make something like following.

byte[] clistAsByteArray = Properties.Resources.CLIST01;

CLIST01 is the name of the embedded file.

Actually you can go to the resources.Designer.cs and see what is the name of the getter.

View more solutions

Comments

[Me.Close]

Great, thanks man. I had a second question regarding the save path, how would I specify it so it would save it to the desktop on any computer which would perhaps have different directory structure?

[adrianbanks]

@Me.Close: Have a look at Environment.SpecialFolder to get the desktop folder. You need to bear in mind that the resource will be namespaced based on its path within the project, so its name may not be just file1.txt.

[Kirk Broadhurst]

+1 For including the namespace as part of the resource name

[Oscar Foley]

var auxList= System.Reflection.Assembly.GetExecutingAssembly().GetManifes‌​tResourceNames(); This method could be very useful when you want to learn the exact resource name. (Taken from question stackoverflow.com/questions/27757/…)

[JYelton]

The argument for GetManifestResourceStream needs the path as @adrian indicates. If it helps anyone, that path is like what @SimpleCoder shows in the example: MyNamespace.Filename.Ext. I had previously tried MyNamespace.Resources.Filename.Ext but that results in a null.

[Suzanne Soy]

Could you please explain this more? When i right-click->properties on a file in the solution explorer, and then set Action to Incorporated ressource, I don't have any Access Modifiers field in the properties panel. Also, I don't have a Propersites.Resources class, I get a The name 'Properties' does not exist in the current context error when compiling your code.

[Sasha]

If you have your resource not directly in the project root, but in some subfolder, don't forget to put this folder name in resourceName as well (e.g. "MyProjectNameSpace.MyProjectSubFolder.FileName.FileExtentio‌​n")

[ouflak]

You can also use this with a text file, in which case you would have: string jsonSecrets = YourNameSpace.Properties.Resources.YourFileName;

[v.oddou]

that's weird for me Properties.Resources.myfile happens to be directly a string and usable in code.

[Timmerz]

are you sure about that? according this this link it looks like I am....stackoverflow.com/questions/1065168/…

[Contango]

This will only work if you embed the file into Resources.resx, see my answer on the different methods to embed files into a project.

[Illidan]

Worth to say that resource "Build Action" has to be set as "Embedded Resource"

[Contango]

A third method is to add the file to the project, then set "Copy to Output Directory" to "True". On compile, the file is copied into the output dir, and you can read the file using normal means. Example: in a WPF app when you want to display an image.

[Felix Keil]

Sorry. This is wrong. Dots work. (at least it worked for me, NET4.5) I don't know why you had this bug.

[Peter Gfader]

Yes they work but they act as Directory separator. Templates.plainEmailBodyTemplate.en.txt will look for "\Templates\plainEmailBodyTemplate\en.txt" resource

[Felix Keil]

No. I tried it. GetManifestResourceStream can access embedded resources with more than one dot in the filename. (NET4.5)

[Nicolas Fall]

so setting the build action to Resource does nothing that allows you to read out the item as a resource? you have to use EmbeddedResource or add to a Resources.resx file?

[Contango]

@Maslow Setting the build action to 'Resource' creates a linked resource, whereas setting the build action to 'Embedded Resource' compiles the resource into the output assembly. The term 'linked resource' is a fancy term for 'copy the file into the output directory on compile' (you can then read the file at runtime using any normal method). For more on the difference between these two types, see Adding and Editing Resources (Visual C#) at msdn.microsoft.com/en-us/library/7k989cfy(v=vs.90).aspx.

[Kinetic]

One important point not covered here. If you saved your file as an alternative encoding type to cope with odd characters (in my case UTF8), you may get an empty file back when you read the stream. Fix this by specifying the encoding type in the constructor of the stream reader: using (StreamReader reader = new StreamReader(stream, Encoding.UTF8))

[ff8mania]

I did it in a dll (not an executable) and stream is always empty. Do I have to use the signature with the explicit type?

[Harry]

And what about super simple solution: var resName = assembly.GetManifestResourceNames().Where(i => i.EndsWith(fileName)).FirstOrDefault(); It won't work if you place whole directories into assembly, but otherwise it's just one line ;)

[Felix Keil]

@Harry sure you can do this. How does this correlate with my answer? Do you want to improve the GetStream Method? And how do you handle ambiguity then?

[Harry]

Yes, I wanted to do a little improvement. OK: var a = Assembly.GetExecutingAssembly(); using (var s = a.GetManifestResourceStream($"{a.EntryPoint.ReflectedType.Na‌​mespace}.{name}")) { /* here use the stream */ } - here's the way to handle ambiguity, seems like we have to use Namespace somewhere. I just looked for shorter and more compact way to get to MRS, you know, with best no dependency outside the method. I'm not sure if it's useful though, anyway I used in my self-extractor so I share.

[Estevez]

What references do you have for 'EmbeddedResources'? using System... ; ???

[Felix Keil]

@Estevez using System; using System.IO; using System.Linq; using System.Reflection;

[a.farkas2508]

I had a same problem in .NET 4.5. Files with dots in name were not even added to resource collection. Method assembly.GetManifestResourceNames() returns empty list to me.Later I've found out that problem was only with language code. ca.abcd.sk.crt was not added to resources while ca.abcd.crt was added without problem.

[Alok]

plus one for captain planet :P

[Ievgen]

To fix that you should use "._" instead of ".". Check this out: Templates.plainEmailBodyTemplate._en.txt

[Mike Gledhill]

Yup, it's now 3 years later, and this restriction still exists in VS2017. If you have an "Embedded Resource" called "captions.en.json", it simply doesn't get included. Changing the filename to "captions-en.json" solves the problem. Grrrr....

[Curly Brace]

For some reason class doesn't work when placed in another project. Calling and Executing assemblies are both refer to the assembly with this class, not the one that actually executes tests. Without static and lazy initialization all good, tho.

[Felix Keil]

@CurlyBrace Thank you. The lazy evaluation is a real flaw in this answer, because the calling & executing assemblies change dependending on the context. They need to be resolved on every access.

[Mark]

Hyphens ("-") in names will be replaced with underscores ("_").

[Admin]

It will return byte[] , for text files use ` Encoding.UTF8.GetString(Properties.Resources.Testfile)`

[Kaido]

Use assembly.GetManifestResourceNames to find the generated name

[TinyRacoon]

If you haven't set the AssemblyCompany field in AssemblyInfo.cs then you can omit it. i.e. "MyProduct.MyFile.txt"

[noelicus]

Er ... SignificantDrawerCompiler ?

[Abdul Saleem]

Very well explained. Thank you

[JoeTomks]

Also confused as to what SignificantDrawerCompiler is?

[Lkor]

If you would like to use resources this way, but dynamically, just instead of this: Properties.Resources.Your_resource_name write this: Properties.Resources.ResourceManager.GetObject("Your_resourc‌​e_name").

[ZeRemz]

Still correct in 2020. Thanks a lot for this, I was getting crazy with this.

[Ian C Tubman]

To get assembly name to prefix, I use: Assembly.GetExecutingAssembly().GetName().Name.ToString()

[BullyWiiPlaza]

@Krythic: It's obvious if you copy the whole class into your source code. Your IDE will resolve everything automatically then. I already included the using statements so the information was not missing from the answer.

[BullyWiiPlaza]

@Krythic: It's edited now to remove the static usings

[Elnoor]

That will return byte array not string

[Fabian]

There is now an overload for GetManifestResourceStream that allows to pass a type. So the specification of the namespace is not necessary anymore. This allows to remove the GetManifestResourceNames look up. See answer by Saeb Amini

[Mike W]

where is Properties defined?

[quemeful]

When designing this part of Xamarin, who was sitting there and thought, "hey! this could would make sense for reading from a text file!" Assembly.GetExecutingAssembly().GetManifestResourceStream(re‌​sourceName)

[quemeful]

once I read the code SignificantDrawerCompiler seems optional

[quemeful]

in order to use .Single() I think you need to use .toList()

[David Bentley]

@Elnoor I do not believe this is true or at least not true with all versions. of .NetCore/Framework. I tested this with .Net 4.0 and fileNameSpace.Properties.Resources.fileName; is a string type.

[Elnoor]

I have tested in Core. Maybe in Net standard yeah will return string

[Kira Resari]

This answer actually helped me figure out what I was still missing: setting "Build Action: Embedded Resource" in the files. I was wondering why they didn't show up. Now I'm wondering why this isn't the default setting. Is there any reason why you would add a file as a resource and not have it embedded?

[SendETHToThisAddress]

Thank you! This was the only answer that worked for me, which had intelligible steps I could understand. My app did not have a resource file and I had to create one. Only thing was on step 1 for me there was no Add button, I had to click save instead.

[Barkermn01]

Thanks so much for this just a polite notice it's missing a using System.Reflection; :D

[H3sDW11e]

so much Garbage Collector this C#( that is the joke on you ) :: how to only load it like :: return new System.Uri(@"pack://application:,,,/RESOURCES/MyText.txt",Sy‌​stem.UriKind.Relativ‌​eOrAbsolute);