Understanding Isolated Storage - Day 3 - Part 6

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Description

Each Windows Phone 7 application is allocated space on the phone's flash drive where it can store information in a solitary area that cannot be accessed by other applications. The application can save any type of file or data here. In this video, Bob demonstrates how to utilize this feature to create new files or open existing files (like text files), read them, and display their information on the Phone's display.

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The Discussion

  • User profile image
    Brendan

    Hi Bob
    Where abouts is isolated storage found on the computer during wp7 emulation? This would be convenient to know for debugging.
    Thanks,
    Brendan

  • User profile image
    Stephen Borders

    I am getting errors on the "IsolatedStorageFile" and "StreamWriter" items in the code. I have both verified the code is the same as the video and copied the Code from the MainPage.Xaml.cs source code and it still flags it as an error.

  • User profile image
    TimothyRice

    I'm also getting the same issues with IsolateStorageFile and StreamWriter :/

  • User profile image
    TimothyRice

    If you pause the video at 3:14, you can see that new code appears in lines 13 and 14.  Adding the following code to lines 13 and 14 appears to solve the issue.

    using System.IO.IsolatedStorage;
    using System.IO;

  • User profile image
    Aaron Agema

    this also brings up the (small) issue, that if someone were to get this exact example from the marketplace and click the "open" button before anything was saved, you would have the same issue as when restarting your phone emulator, i.e. the unhandled exception. make sure to use some kind of error-catching, or at least a simple if statement to check whether the file exists.

  • User profile image
    dicey

    The thing is the data stored are not overwritten when a new data is stored. hence when the new data (e.g. 12345) has less characters than the previous data (e.g. 987654321), and when we recall the data, the part of the prvious data after the new data is recalled as well (e.g. 123454321).

    So how do we completely clear out the previous data when the new data is stored?

  • User profile image
    petaganayr

    Very cool indeed.

  • User profile image
    Shawn

    Great video series!!
    My question relates to the saved file (simple.txt) and the open/recall function. When the user enters new information and saves it to the flash memory of the device, the old entry is not completely overwritten. The user has to termintate the program to completely clear the initial message from the flash memory. Is there a fix to this? If so, what is it? That would have been a great ending to this video...and helped me tremendously!

  • User profile image
    Cyrill

    @Shawn: You need to delete the file before writing with something like

    using

    (IsolatedStorageFile storage = IsolatedStorageFile.GetUserStoreForApplication())
    {
    storage.Remove();

    }

     

  • User profile image
    minompi

    Hi, i have a question:

    if I switch off my phone after saved my file, when i restart the phone the file is deleted, clear, or is the same that i have svaed before?

    Thanks

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