将文件从可移植类库复制到 Windows 8 - SQLite 数据库答案

【问题标题】：Copy file from portable class library to Windows 8 - SQLite database将文件从可移植类库复制到 Windows 8 - SQLite 数据库
【发布时间】：2014-03-29 21:45:01
【问题描述】：

我有一个 SQLite 数据库文件，我需要将它复制到将要使用它的平台上，而且我有点笨拙。我已经看到了有关如何读取文本的示例，例如从 xml 文件中读取文本，但我只需要获取一个流并复制它，但我找不到我需要使用哪个类。

这是我目前所拥有的：

public async Task CopyDatabase()
    {
        var s = Assembly.Load(new AssemblyName("PhenotypesLibrary")).GetManifestResourceStream(DBPath.DBPathAsString());

        ////create a folder and file
        var folder = ApplicationData.Current.LocalFolder;
        var file = await folder.CreateFileAsync(DBPath.DBPathAsString());


        using (IRandomAccessStream fileStream = await file.OpenAsync(FileAccessMode.ReadWrite))
        {
            using (IOutputStream outputStream = fileStream.GetOutputStreamAt(0))
            {
                using (StreamWriter writer = new StreamWriter(outputStream.AsStreamForWrite()))
                {
                    await writer.//ummmmmmmmm
                }
                //using (DataWriter dataWriter = new DataWriter(outputStream))
                //{ 

                //    var bytes = 
                //    dataWriter.WriteBytes
                //}
            }
        }

        // the way I did it from a file that was put in the project folder, not in a PCL
        //string path = DBPath.DBPathAsString();
        //bool copy = false;
        //try
        //{
        //    StorageFile file = await ApplicationData.Current.LocalFolder.GetFileAsync(path);
        //}
        //catch 
        //{
        //    copy = true;
        //}

        //if (copy)
        //{
        //    var file = await StorageFile.GetFileFromApplicationUriAsync(new Uri("ms-appx:///" + path));
        //    await file.CopyAsync(ApplicationData.Current.LocalFolder);
        //}
    }

【问题讨论】：

标签： sqlite portable-class-library

【解决方案1】：

我找到了答案。我不太清楚如何为 PCL 做目录，所以我把文件放到了 PCL 的根目录中。

    public async Task CopyDatabase()
    {
        if (await CheckFileExists()) return;

        Assembly assembly = Assembly.Load(new AssemblyName("PhenotypesLibrary"));
        var s = assembly.GetManifestResourceStream(DBPath.FullDBPath);

        DataReader dataReader = new DataReader(s.AsInputStream());
        await dataReader.LoadAsync((uint)s.Length);
        byte[] buffer = new byte[(int)s.Length];
        dataReader.ReadBytes(buffer);

        var file = await Windows.Storage.ApplicationData.Current.LocalFolder.CreateFileAsync(DBPath.DBPathAsString);
        await Windows.Storage.FileIO.WriteBytesAsync(file, buffer);

    }

    private static async Task<bool> CheckFileExists()
    {
        bool fileExists = false;
        try
        {
            var alreadyCopiedFile = await ApplicationData.Current.LocalFolder.GetFileAsync(DBPath.DBPathAsString);
            fileExists = true;
        }
        catch { }
        return fileExists;
    }
    /// <summary>
    /// The path to the database.
    /// </summary>
    public static string DBPathAsString = @"phenotypes_database.sqlite";

    /// <summary>
    /// The Path to the file for the Assembly.GetManifestResourceStream method.
    /// </summary>
    public static string FullDBPath = "PhenotypesLibrary.Database.phenotypes_database.sqlite";

【讨论】：