Description
Description
The path of a file created by IsolatedStorageFile.GetUserStoreForApplication() changes between Xamarin.iOS and .NET 6, and also changes between different builds of the application under .NET 6.
This makes IsolatedStorageFile unusable in .NET 6 since an updated build cannot open a file created by a previous build. Each time the build is updated, all of the files previously created on behalf of the user are effectively gone.
For example, the following code:
using (IsolatedStorageFile store = IsolatedStorageFile.GetUserStoreForApplication()) {
using (IsolatedStorageFileStream stream = store.OpenFile("settings.txt", FileMode.Create)) {
// Write file contents here
results in the file being written to various locations in the iOS device file system depending on the build of the application:
/var/mobile/Containers/Data/Application/<GUID>/Documents/IsolatedStorage/tz12rggn.q0z/hi51wlzn.hmf/Url.j1gfq4nxq1m4zfi31rjvtcuna3umf3fb/AppFiles/settings.txt
/var/mobile/Containers/Data/Application/<GUID>/Documents/IsolatedStorage/tz12rggn.q0z/hi51wlzn.hmf/Url.vb0fraupqrlwtvom530yjpnqlhlbggfc/AppFiles/settings.txt
/var/mobile/Containers/Data/Application/<GUID>/Documents/IsolatedStorage/tz12rggn.q0z/hi51wlzn.hmf/Url.az1iqc1z0lv42e3agh4zvg5aa5rbihzj/AppFiles/settings.txt
/var/mobile/Containers/Data/Application/<GUID>/Documents/IsolatedStorage/tz12rggn.q0z/hi51wlzn.hmf/Url.efra4nhzgkrws2l30v4hbayjiohm2ofj/AppFiles/settings.txt
...
In Xamarin.iOS the path of the file was consistent across builds of the app.
Reproduction Steps
Build the code below on Xamarin.iOS and execute on an iOS device.
Migrate the app to dotnet 6, rebuild and execute on the same iOS device.
Note that the file is created in a different file system location on the device.
Clean and rebuild the dotnet 6 app and execute on the same iOS device.
Note that the file is created in yet another file system location on the device.
using (IsolatedStorageFile store = IsolatedStorageFile.GetUserStoreForApplication()) {
using (IsolatedStorageFileStream stream = store.OpenFile("settings.txt", FileMode.Create)) {
}
}
Expected behavior
The settings.txt file should be created in the same file system location (path) for every version of the built application.
Actual behavior
The settings.txt file is created in a different file system location (path) for every version of the built application on dotnet 6
Regression?
Yes, this is a regression. The file system path for IsolatedStorageFile was consistent in .NET Framework applications I've built over the past decade with many different versions of .NET and Xamarin.iOS.
Known Workarounds
I don't know of any workaround using the .NET 6 IsolatedStorageFile API. Applications would have to use some other file system API and maybe Environment.GetFolderPath(SpecialFolder folder).
Configuration
.NET 6
iOS
ARM64
This issue is specific to .NET 6 on iOS
Other information
No response