StorageFile Async usage in a NON Metro application

Question

I am trying to create an instance of StorageFile in my class library...

var localFolder = ApplicationData.Current.LocalFolder;
StorageFile destinationFile =          


        

Answer 1

Looks like you are trying to use a type from the WinRT libraries because the StorageFile class documentation states it applies to Metro only and it is found in Windows.Storage.

This blog post goes through how to build it, but it appears to be a manual process. It also details the cause of the error:

Using the await keyword causes the compiler to look for a GetAwaiter method on this interface. Since IAsyncOperation does not define a GetAwaiter method, the compiler wants to look for an extension method.

Basically, it looks like you need to add a reference to: System.Runtime.WindowsRuntime.dll

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Please take the time to read his blog post, but I will put the important part here for clarity.

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Blog Content Below Unceremoniously Plagiarised

First, in Notepad, I created the following C# source code in EnumDevices.cs:

using System;
using System.Threading.Tasks;
using Windows.Devices.Enumeration;
using Windows.Foundation;

class App {
    static void Main() {
        EnumDevices().Wait();
    }

    private static async Task EnumDevices() {
        // To call DeviceInformation.FindAllAsync:
        // Reference Windows.Devices.Enumeration.winmd when building
        // Add the "using Windows.Devices.Enumeration;" directive (as shown above)
        foreach (DeviceInformation di in await DeviceInformation.FindAllAsync()) {
            Console.WriteLine(di.Name);
        }
    }
}

Second, I created a Build.bat file which I run from the Developer Command Prompt to build this code (This should be 1 line but I wrap it here for read ability):

csc EnumDevices.cs  
/r:c:\Windows\System32\WinMetadata\Windows.Devices.Enumeration.winmd  
/r:c:\Windows\System32\WinMetadata\Windows.Foundation.winmd 
/r:System.Runtime.WindowsRuntime.dll  
/r:System.Threading.Tasks.dll

Then, at the command prompt, I just run the EnumDevices.exe to see the output.