如何在UWP应用程序中将文本附加到文件

var folder = await Windows.Storage.StorageFolder.GetFolderFromPathAsync("文件夹路径");
var file = await folder.CreateFileAsync("文件名.txt", Windows.Storage.CreationCollisionOption.GenerateUniqueName);

using (var stream = await file.OpenAsync(Windows.Storage.FileAccessMode.ReadWrite))
{
    using (var writer = new Windows.Storage.Streams.DataWriter(stream))
    {
        writer.WriteString("要附加的文本");
        await writer.StoreAsync();
        await writer.FlushAsync();
    }
}

await Windows.Storage.FileIO.AppendTextAsync(file, "要附加的文本");

async void AppendTextToFile()
{
    var folder = await Windows.Storage.StorageFolder.GetFolderFromPathAsync("文件夹路径");
    var file = await folder.CreateFileAsync("文件名.txt", Windows.Storage.CreationCollisionOption.GenerateUniqueName);

    using (var stream = await file.OpenAsync(Windows.Storage.FileAccessMode.ReadWrite))
    {
        using (var writer = new Windows.Storage.Streams.DataWriter(stream))
        {
            writer.WriteString("要附加的文本");
            await writer.StoreAsync();
            await writer.FlushAsync();
        }
    }

    // 如果文件已经存在，附加文本到文件的末尾
    await Windows.Storage.FileIO.AppendTextAsync(file, "要附加的文本");
}