Unable to use Windows.Storage.FileIO.WriteTextAsync

Question

I am building a C# metro app using VS2011 express for Windows Developer Preview.

The app intends to write some data in a text file in the temp location through an "async" function that has the following code-

Windows.Storage.StorageFile file = await Windows.Storage.ApplicationData.Curent.TemporaryFolder.CreateFileAsync("a.txt");

            //await Windows.Storage.FileIO.WriteTextAsync(file, "\n try n try again");

The line #2 has to be commented as it fails to compile with the following error - 

"The type or namespace name 'FileIO' does not exist in the namespace 'Windows.Storage' (are you missing an assembly reference?). "

I fail to understand this behaviour as "FileIO" namespace is everywhere mentioned to be a part of "Windows.Storage". Can somebody help please?

Answer 1

Why Developer Preview(DP)?
DP does not have the Windows.Storage.FileIO class.

If you want to still use DP, please check about the Windows.Storage.Streams.DataWriter class.
However, the official documents are already deleted. Please search blogs etc.
For example: http://www.sharpgis.net/post/2012/01/12/Reading-and-Writing-text-files-in-Windows-8-Metro.aspx

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biac [ http://bluewatersoft.cocolog-nifty.com/ ]

Answer 2

Biac is correct - please upgrade to Consumer Preview to use the latest APIs.

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Matt Small - Microsoft Escalation Engineer - Forum Moderator

Answer 3

Thanks a lot for the clarification!

Does this mean that from a developer's perspective, the Win8 "consumer preview" is an upgraded version of the "developer preview" as it has more functionality?

Answer 4

Yes, it's an upgraded version of Windows 8.  CP contains bug fixes and new functionality that DP did not have.   The same will be true of the next version as well.

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Matt Small - Microsoft Escalation Engineer - Forum Moderator