文件和流的相互转化

public class UploadFile
{
    //文件名称
    public string FileName{get;set;}
    //文件类型
    public StorageFile File{get;set;}
    
    //文件数据流
   public Stream FileStream { get; private set; }
   
   
    public UploadFile(StorageFile file)
    {
        this.StorageFile=file.Name;
        this.File=file;
    }
    
    //将文件转换成流
    public async Task<byte[]> GetBytes()
    {
        FileStream =(Stream) await File.OpenStreamForReadAsync();
        byte[] bytes = new byte[FileStream.Length];
        FileStream.Read(bytes, 0, bytes.Length);
        FileStream.Seek(0, SeekOrigin.Begin);
        return bytes;
    }
    
    
    
    //将流写入文件
       public async void GetFile(Byte[] bytes)
        { 
            StorageFolder applicationFolder = ApplicationData.Current.LocalFolder;
            StorageFile storageFile = await applicationFolder.CreateFileAsync("1.txt", CreationCollisionOption.ReplaceExisting);
            StorageFile file = await applicationFolder.GetFileAsync("1.txt");
            using (var stream = await file.OpenStreamForWriteAsync())
            {
                await stream.WriteAsync(bytes, 0, bytes.Length);
                stream.Flush();
            }

    
}