Sample Download : http://code.msdn.microsoft.com/How-to-check-if-a-file-or-2f9357be
This code snippet will show you how to check if a file or folder exists in the local storage in Windows Store apps.
Use the StorageFolder.TryGetItemAsync method to try to get a file or folder by name, without the need to add error-catching logic to your code (like you would if you used StorageFolder.GetItemAsync). If the file or folder can't be found, TryGetItemAsync will return null and will not raise an exception. Because the method returns null, you can use it to check if the specified file or folder exists.
You can find more code samples that demonstrate the most typical programming scenarios by using Microsoft All-In-One Code Framework Sample Browser or Sample Browser Visual Studio extension. They give you the flexibility to search samples, download samples on demand, manage the downloaded samples in a centralized place, and automatically be notified about sample updates. If it is the first time that you hear about Microsoft All-In-One Code Framework, please watch the introduction video on Microsoft Showcase, or read the introduction on our homepage http://1code.codeplex.com/.