exceptionwindows-8windows-runtimelocal-storagewinrt-async

A method was called at an unexpected time

I'm trying to iterate all files in a directory using GetFilesAsync, but every time I call the GetResults method, it throws an exception that says

System.InvalidOperationException: A method was called at an unexpected time

The code is simply

var files = myStorageFolder.GetFilesAsync(); //runs fine
var results = files.GetResults(); //throws the exception

I'm new to Win 8 dev so I might be missing something obvious.

Edit (solved) I'm running my console application, but now that the program runs async, the files.GetResult() method no longer exists. 

static void Main(string[] args)
{
   var files = GetFiles(myStorageFolder);
   var results = files.GetAwaiter().GetResults();//Need to add GetAwaiter()
}

static async Task GetFiles(StorageFolder sf)
{
   await sf.GetFilesAsync();
}
Solution

  • You need to wait for the async method to complete. So you could use the new await as one option:

    var files = await myStorageFolder.GetFilesAsync();

    You might want to check the documentation on dealing with async methods here.