Copying embedded resource as file to disk in C#

Question

I have an INF file saved as an embedded resource in my C# project. I am trying to save this file to a local location on demand. I am using this method.

public static void SaveResourceToDisk(string ResourceName, string FileToExtractTo)
{
    Stream s = Assembly.GetExecutingAssembly().GetManifestResourceStream(ResourceName);
    FileStream resourceFile = new FileStream(FileToExtractTo, FileMode.Create);

    byte[] b = new byte[s.Length + 1];
    s.Read(b, 0, Convert.ToInt32(s.Length));
    resourceFile.Write(b, 0, Convert.ToInt32(b.Length - 1));
    resourceFile.Flush();
    resourceFile.Close();

    resourceFile = null;
}

When I try to call this method (passing the resource name along with the namespace name), I get the error:

Object reference not set to an instance of an object

What am I doing wrong here?

If you posted the full error (including line number, matched against the line number in your code) it may help in diagnosing the issue. — dreadwail, Dec 10 '10 at 05:07
A side tip: Consider using the "using" keyword with your objects to automatically dispose of them. — dreadwail, Dec 10 '10 at 05:09
Duplicate of http://stackoverflow.com/questions/864140/write-file-from-assembly-resource-stream-to-disk, which has a more useful code example. — pennyrave, Aug 09 '12 at 16:42

score 12 · Accepted Answer · answered Dec 10 '10 at 05:13

12

You could call

System.Reflection.Assembly.GetExecutingAssembly().GetManifestResourceNames();

And inspect which embedded resources are accessible. Then you can compare that against what you are passing in to see if you are indeed accomplishing what you expected to.

Also, you should consider the using keyword to dispose of your streams:

using(FileStream ResourceFile = new FileStream(FileToExtractTo, FileMode.Create))
{
    //do stuff
}

Good luck.

answered Dec 10 '10 at 05:13

dreadwail

15,098
21
65
96

Okay, got it. I was using `GetManifestResourceStream(namespace.resourcename)` when I should've been usign `GetManifestResourceStream(namespace.Resources.resourcename)`. And thanks for the `using` tip! – GPX Dec 10 '10 at 05:23

score 6 · Answer 2 · answered Oct 02 '15 at 17:31

This is the easiest way to save an embedded resource:

  var stream = assembly.GetManifestResourceStream("name of the manifest resourse");
  var fileStream = File.Create(@"C:\Test.xml");
  stream.Seek(0, SeekOrigin.Begin);
  stream.CopyTo(fileStream);
  fileStream.Close();

score 1 · Answer 3 · answered Jul 04 '16 at 15:25

Unpacks all embedded resources within an assembly and saves them alongside the assembly containing this class while maintaining the directory structure. This code does not require you to know anything about the files contained within the assembly and is a more generic solution but it does assume that all files have file extensions.

public class EmbeddedResources
{
    private bool isUnpacked = false;

    public async Task EnsureUnpacked(string saveDirectory)
    {
        if (!this.isUnpacked)
        {
            var assembly = Assembly.GetExecutingAssembly();
            var assemblyDirectory = Path.GetDirectoryName(assembly.Location);
            foreach (var name in assembly.GetManifestResourceNames())
            {
                var stream = assembly.GetManifestResourceStream(name);

                var stringBuilder = new StringBuilder();
                var parts = name
                    .Replace(typeof(EmbeddedResources).Namespace + ".", string.Empty)
                    .Split('.')
                    .ToList();
                for (int i = 0; i < parts.Count; ++i)
                {
                    var part = parts[i];
                    if (string.Equals(part, string.Empty))
                    {
                        stringBuilder.Append(".");      // Append '.' in file name.
                    }
                    else if (i == parts.Count - 2)
                    {
                        stringBuilder.Append(part);     // Append file name and '.'.
                        stringBuilder.Append('.');
                    }
                    else if (i == parts.Count - 1)
                    {
                        stringBuilder.Append(part);     // Append file extension.
                    }
                    else
                    {
                        stringBuilder.Append(part);     // Append file path.
                        stringBuilder.Append('\\');
                    }
                }

                var filePath = Path.Combine(saveDirectory, stringBuilder.ToString());
                using (FileStream fileStream = new FileStream(filePath, FileMode.OpenOrCreate, FileAccess.ReadWrite))
                {
                    await stream.CopyToAsync(fileStream);
                }
            }

            this.isUnpacked = true;
        }
    }
}

score 0 · Answer 4 · answered Oct 11 '19 at 16:17

0

attach your file in your project. click on attached file.go to properties,set set Build Action to Embedded Resource, use file name in code like this: "YourProjectName.YourFileNameIWithExt"

answered Oct 11 '19 at 16:17

Sharif Lotfi

544
6
13

Gonzo345 · Answer 5 · 2021-02-18T10:43:20.367

I had an Excel file added into my Resources and had no luck using other's solutions. This was due to the file itself is accessed as a byte[] through the Properties.Resources instead of picking up the string path routing.

So I simply ask the user for a saving path and then I use the System.IO.File.WriteAllBytes method:

using (var save = new SaveFileDialog())
{
    save.Title = "File path for saving the file";
    save.FileName = "Excel file.xlsx";
    save.Filter = "Excel files|*.xlsx;*.xls";
    var dialog = save.ShowDialog();
    if (dialog != DialogResult.OK)
        return;

    System.IO.File.WriteAllBytes(save.FileName, Resources.ExcelFile);
}

Copying embedded resource as file to disk in C#

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