How to copy a local DB in Xamarin.Forms?

Question

I created a project where I'm trying to copy to local files in Xamarin.Forms, one is an XML and one is a local DB in SQLite:

I configured them as EmbeddedResources. I tried to access their current location using this:

public static class Constants  
{  
        public const string DatabaseFilename = "savethatpower.db";  
  
        public const SQLite.SQLiteOpenFlags Flags =  
            // open the database in read/write mode  
            SQLite.SQLiteOpenFlags.ReadWrite |  
            // create the database if it doesn't exist  
            SQLite.SQLiteOpenFlags.Create |  
            // enable multi-threaded database access  
            SQLite.SQLiteOpenFlags.SharedCache;  
  
        public static string DatabasePath  
        {  
            get  
            {  
                var basePath = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);  
                return Path.Combine(basePath, DatabaseFilename);  
            }  
        }  
}  
  
public void CopyFiles(string name) {  
  
    var localPath = $"{Application.Current.Resources.Source.AbsolutePath}/{name}";  
  
    File.Copy(localPath, Constants.DatabasePath);  
}  
  
CopyFiles("savethatpower.db");  
CopyFiles("dbInfo.xml");  

This line provides me a tricky bug since the beginning: var localPath = $"{Application.Current.Resources.Source.AbsolutePath}/{name}";

InnerException	{System.NullReferenceException: Object reference not set to an instance of an object   at SaveThatPower.Classes.XML.XML2CSharp..ctor (System.String name) [0x00008] in /Users/fanmixco/Documents/GitHub/SaveThatPower/SaveThatPower/SaveThatPower/Classes/XML/XML2CSh…}	System.NullReferenceException  

I found that the Source is null but I don't know how to access its current location. I also tried directly accessing the files like this:

    File.Copy("dbVersion.xml", Constants.DatabasePath);  

But nothing happened. I'm wondering, do you know what is the correct way to copy files? Thanks.

Answer 1

This is my solution:

public class FileActions
{
    public async Task CopyFile(string name)
    {
        var basePath = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
        var finalPath = Path.Combine(basePath, name);

        if (File.Exists(finalPath))
        {
            File.Delete(finalPath);
        }

        var assembly = GetType().Assembly;
        var tmpName = $"{assembly.GetName().Name}.{name}";
        using var tempFileStream = assembly.GetManifestResourceStream(tmpName);
        using var fileStream = File.Open(finalPath, FileMode.CreateNew);
        await tempFileStream.CopyToAsync(fileStream);
    }
}

It is based on Cheesebaron's one.