写入（读取）IO.Stream到（从）ApplicationData.Current.LocalFolder

Question

什么是读取amnd写入和IO.Stream（Zip文件从Internet上downloded到我的情况）到ApplicationData.Current.LocalFolder

我试图

public static async Task WriteToFile(
     this System.IO.Stream input, 
     string fileName, 
     StorageFolder folder = null) 
    { 
     folder = folder ?? ApplicationData.Current.LocalFolder; 
     var file = await folder.CreateFileAsync(
      fileName, 
      CreationCollisionOption.ReplaceExisting); 
     using (var fs = await file.OpenAsync(FileAccessMode.ReadWrite)) 
     { 
      using (var outStream = fs.GetOutputStreamAt(0)) 
      { 
       using (var dataWriter = new DataWriter(outStream)) 
       { 
        byte[] buffer = new byte[8 * 1024]; 
        int len; 
        while ((len = input.Read(buffer, 0, buffer.Length)) > 0) 
        { 
         dataWriter.WriteBytes(buffer); 
        } 

        await dataWriter.StoreAsync(); 
        dataWriter.DetachStream(); 
       } 

       await outStream.FlushAsync(); 
      } 
     } 
    } 

写作和

StorageFile file = await ApplicationData.Current.LocalFolder.GetFileAsync(filename); 
var fileStream = await file.OpenAsync(Windows.Storage.FileAccessMode.Read); 
var stream = fileStream.AsStreamForRead(); 

但文件被损坏沿way.I地方做没想到有一个与阅读的问题，所以应该以书面日在某处e文件。有没有更好的方法来编写IO.Stream到ApplicationData.Current.LocalFolder的工作？

Answer 1

试试这个：

static async void DownloadFileAsync(
    this HttpClient httpClient, 
    string requestUri, 
    string fileName, 
    StorageFolder folder = null) 
{ 
    folder = folder ?? ApplicationData.Current.LocalFolder; 

    var file = await folder.CreateFileAsync(
     fileName, CreationCollisionOption.ReplaceExisting); 

    using (var httpStream = await httpClient.GetStreamAsync(uri)) 
    using (var fileStream = await file.OpenAsync(FileAccessMode.ReadWrite)) 
    { 
     await httpStream.CopyToAsync(fileStream.AsStreamForWrite()); 
    } 
} 

MSDN：Http­Client Class，Http­Client.­Get­Stream­Async Method，Windows­Runtime­Stream­Extensions.­As­Stream­For­Write Method，Stream.­Copy­To­Async Method。