如何讓PDF文件到臨時存儲文件，從URL中的Windows Phone 8.1

Question

var uri = new System.Uri("ms-appx:///Assets/FixesViaMail_17Dec.pdf", UriKind.Absolute); 
StorageFile file = await Windows.Storage.StorageFile.GetFileFromApplicationUriAsync(uri); 

這段代碼，因爲使用我的系統文件路徑，但每當我使用此代碼

var uri = new System.Uri("http://www.visa.com/assets/upload/11458/Hotel/Voucher114581423144270.pdf", UriKind.Absolute); 
StorageFile file = await Windows.Storage.StorageFile.GetFileFromApplicationUriAsync(uri); 

進出口工作非常出色那麼我得到的錯誤是..... 價值不在預期範圍內。

請幫我

Answer 1

GetFileFromApplicationUriAsync僅用於從您的應用程序中加載文件。要從網上閱讀文件，您需要下載它。您可以使用HttpClient（對於小文件）或BackgroundDownloader（對於大文件）類來執行此操作。

var uri = new Uri("http://www.visa.com/assets/upload/11458/Hotel/Voucher114581423144270.pdf"); 
var httpClient = new HttpClient(); 

// Always catch network exceptions for async methods 
try 
{ 
    var response = await httpClient.GetAsync(uri); 
    // save response out 
} 
catch 
{ 
    // Details in ex.Message and ex.HResult.  
} 

查看Connecting to an HTTP server using Windows.Web.Http.HttpClient (XAML)瞭解更多詳情。

var uri = new Uri("http://www.visa.com/assets/upload/11458/Hotel/Voucher114581423144270.pdf"); 
BackgroundDownloader download = new BackgroundDownloader(); 
DownloadOperation download = downloader.CreateDownload(uri, destinationFile); 

有關更多詳細信息，請參見Transferring data in the background。