GetBasicPropertiesAsync在WinRT

Question

我正在使用GetBasicPropertiesAsync()来计算手机上的可用空间（Windows Phone 8.1 RT应用程序）。

该方法运行正常，但有时会抛出InvalidOperationException导致应用程序崩溃。我得到以下stacktrace：

Exception: System.InvalidOperationException: A method was called at an unexpected time. 
(Exception from HRESULT: 0x8000000E), A method was called at an unexpected time.
(Exception from HRESULT: 0x8000000E), Message: A method was called at an unexpected time.
(Exception from HRESULT: 0x8000000E), Stacktrace:    
at Windows.Storage.StorageFolder.GetBasicPropertiesAsync()

我无法找到此异常的原因。谁能指点一下呢？