将文件从UWP资源复制到本地文件夹

Question

I'm trying to copy a file from the UWP resources into the user's local folder.

The closest I could get was this:

public static void CopyDatabaseIfNotExists(string dbPath)
{
        var storageFile = IsolatedStorageFile.GetUserStoreForApplication();

        if (storageFile.FileExists(dbPath))
        {
            return;
        }

        using (var resourceStream = Application.GetResourceStream(new Uri("preinstalledDB.db", UriKind.Relative)).Stream)
        {
            using (var fileStream = storageFile.CreateFile(dbPath))
            {
                byte[] readBuffer = new byte[4096];
                int bytes = -1;

                while ((bytes = resourceStream.Read(readBuffer, 0, readBuffer.Length)) > 0)
                {
                    fileStream.Write(readBuffer, 0, bytes);
                }
            }
        }
    }

But this doesn't seem to work anymore with UWP. GetResourceStream isn't available anymore ("Application doesn't contain a definition for 'GetResourceStream'").

Could somebody please tell me how do this with UWP?

Thank you very much!

Answer 1

You can do it a bit simpler, just replace ApplicationData.Current.LocalFolder with your desired folder.

try
{
    await ApplicationData.Current.LocalFolder.GetFileAsync("preinstalledDB.db");
    // No exception means it exists
    return;
}
catch (System.IO.FileNotFoundException)
{
// The file obviously doesn't exist
}

// Cant await inside catch, but this works anyway
var storfile = await StorageFile.GetFileFromApplicationUriAsync(new Uri("ms-appx:///preinstalledDB.db"));
await storfile.CopyAsync(ApplicationData.Current.LocalFolder);

The try block may seem strange but it is actually the fastest way to determine if a file exists.