'System.IO.FileNotFoundException'

Question

MyApp.DLL中發生“ System.IO.FileNotFoundException”

C＃代碼如下。 指針在LockScreen.SetImageUri（uri）上指示的錯誤“這是將要執行的下一條語句”。

public partial class MainPage : PhoneApplicationPage
{
    // Constructor
    public MainPage()
    {
        InitializeComponent();
    }


    private async void SetBackground1(object sender, RoutedEventArgs e)
    {
        if (await LockScreenManager.RequestAccessAsync() == LockScreenRequestResult.Granted)
        {
            var uri = new Uri("ms-appx:///Assets/1.jpg", UriKind.Absolute);
            LockScreen.SetImageUri(uri);
        }
        else
        {
            MessageBox.Show("You said no, so I can't update your background.");
        }
    }
}

Answer 1

將圖像保存到隔離存儲而不是項目文件夾。 然后，您可以隨時從隔離的存儲中檢索圖像，

  var lockimageuri = new Uri("ms-appdata:///Local/" + "lockimage0.jpg", UriKind.Absolute);
  LockScreen.SetImageUri(lockimageuri);

locimage0.jpg是隔離存儲中的圖像。

這是將圖像保存到隔離存儲中的代碼。

   using (var store = IsolatedStorageFile.GetUserStoreForApplication())
   {
          string filePath = "lockimage0.jpg";
          if (store.FileExists(filePath))
          {
                store.DeleteFile(filePath);
          }
          IsolatedStorageFileStream fileStream = store.CreateFile(filePath);
          wbm.SaveJpeg(fileStream, wbm.PixelWidth, wbm.PixelHeight, 0, 100);
          fileStream.Close();
     }

您也可以使用此方法從項目文件夾中讀取本地圖像。

 private WriteableBitmap ReadLocalImage(string Uri)
    {
        StreamResourceInfo sri = null;
        Uri uri = new Uri(Uri, UriKind.Relative);
        sri = Application.GetResourceStream(uri);
        BitmapImage bitmap = new BitmapImage();
        bitmap.CreateOptions = BitmapCreateOptions.None;
        bitmap.SetSource(sri.Stream);
        WriteableBitmap wb = new WriteableBitmap(bitmap);
        return wb;

    }

這就是我在應用程序中實現自定義鎖定屏幕的方式。

還要確保您更新了清單文件

<Extensions>
  <Extension ExtensionName="LockScreen_Background" ConsumerID="{111DFF24-AA15-4A96-8006-2BFF8122084F}" TaskID="_default" />
</Extensions>

我也嘗試在本地項目文件夾中使用圖像，這對我也很好。 這是我嘗試的代碼。

private async void SetLockScreen()
{
           //Check to see if the app is currently the lock screen provider
           if (!LockScreenManager.IsProvidedByCurrentApplication)
           {
                //Request to be lock screen provider
                await LockScreenManager.RequestAccessAsync();
           }

           //Check to see if the app is currently the lock screen provider
           if (LockScreenManager.IsProvidedByCurrentApplication)
           {
                //Set the image to the lock screen image
                Uri imageUri = new Uri("ms-appx:///Images/lockscreen.png", UriKind.RelativeOrAbsolute);
               LockScreen.SetImageUri(imageUri);
           }
  }

Answer 2

請確保圖像位於指定位置，並且其Build Action屬性設置為Content ：