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System.Obsolete attribute used instead of ObsoletedOSPlatform attribute #7558
Description
Activity
I am using
net7.0-android33.0but still see the warning.
As I mentioned, some methods are annotated withObsoletedOSPlatformwhile others aren't (they are annotated withSystem.Obsolete).
I basically right-click on the method (GetPackageInfo) in VS22 and select "Go to Definition". It shows me this:
When I do the same for other methods (
GetInstallerPackageName), I see this:
The file appears to be this:
Some of them were deprecated before our minimum API level (21), so they are just marked with the regular
[Obsolete]since they are deprecated in all of our versions:removePackageFromPreferred (String packageName)- deprecated in API-15addPackageToPreferred (String packageName)- deprecated in API-15addPreferredActivity (IntentFilter filter, int match, ComponentName[] set, ComponentName activity)deprecated in API-15
The others were obsoleted in API-33, so they should have the new attribute. Maybe there is something messed up because we have converted the
int flagsto enumerations. I will investigate.This causes a compile error in our Xamarin.Forms apps on Azure DevOps windows-2022 images.
Error CS0618: 'PackageManager.GetPackageInfo(string, PackageInfoFlags)' is obsolete: 'deprecated'This is weird since that signature should be the one that isn't deprecated:
The deprecated one is the int flags overload:
But there appears to be no overload for (
int flags) in the Xamarin.Android references.So this is surely something that needs to be addressed as early as Xamarin.Android, let along NET6/7/8.
But there appears to be no overload for (int flags) in the Xamarin.Android references.
This appears to be a case of us making an unfortunate name choice a long time ago.
The original methods from Google are:
public abstract PackageInfo GetPackageInfo(VersionedPackage versionedPackage, int flags)public abstract PackageInfo GetPackageInfo(string packageName, int flags)
We want our APIs to be a little easier to use, so we converted the
int flagsparameter to an enum calledPackageInfoFlags, so they now look like this:public abstract PackageInfo GetPackageInfo(VersionedPackage versionedPackage, [GeneratedEnum] PackageInfoFlags flags)public abstract PackageInfo GetPackageInfo(string packageName, [GeneratedEnum] PackageInfoFlags flags)
In API-33, it looks like Google has done the same thing we did and introduced new overloads that take an "enum-like" Java type:
public virtual PackageInfo GetPackageInfo(VersionedPackage versionedPackage, PackageManager.PackageInfoFlags flags)public virtual PackageInfo GetPackageInfo(string packageName, PackageManager.PackageInfoFlags flags)
Note that instead of our enum
PackageInfoFlagsthese use a Java classPackageManager.PackageInfoFlagswhich has the same name as our enum but is a different type.Thus you have to look closer to see that methods that take the enum
PackageInfoFlags(theint flagsJava methods) are the ones that are deprecated, and the new methods that take the Java typePackageManager.PackageInfoFlagsare not deprecated.This causes a compile error in our Xamarin.Forms apps on Azure DevOps windows-2022 images.
[Obsolete]does not produce an error, it produces a warning. You likely have some form of<TreatWarningsAsErrors>or<WarningsAsErrors>in your project file. You will need to suppress the warning using the regular C# mechanisms so your project does not treat it as an error.Reacted by jahmai-ca[Obsolete]does not produce an error, it produces a warning. You likely have some form of<TreatWarningsAsErrors>or<WarningsAsErrors>in your project file. You will need to suppress the warning using the regular C# mechanisms so your project does not treat it as an error.We don't. We actually use [Obsolete] ourselves, which generates
warning CS0618without any errors. This specific one gets converted toError CS0618: 'PackageManager.GetPackageInfo(string, PackageInfoFlags)' is obsolete: 'deprecated'and I don't know why.We're going to suppress it in code with
#pragma, but ultimately we want to be able to call the appropriate version of GetPackageInfo since we target API 33 but support down to 23, and don't want to have to upgrade to NET8 to do that...This may also apply to
PackageManager.QueryIntentActivitieswith a similar issue of enum/int flags.- ghost locked as resolved and limited conversation to collaborators
on Feb 5, 2023 - added a commit that references this issue
on Aug 15, 2024
Android application type
Android for .NET (net6.0-android, etc.)
Affected platform version
VS 2022 17.4.1, .NET 7
Description
I am using this property to get the installed app version:
The old (now deprecated)
GetPackageInfomethod still emits this warning, even thoughOperatingSystem.IsAndroidVersionAtLeastis used:Warning CS0618 'PackageManager.GetPackageInfo(string, PackageInfoFlags)' is obsolete: 'deprecated'This is because of this attribute:
[System.Obsolete("deprecated")]I think this attribute should be used instead:
[ObsoletedOSPlatform("android30.0")]I know this is rather nitpicking, but there might be other usages of the old
Obsoleteattribute that could be replaced with theObsoletedOSPlatformattribute. In the PackageManager class alone there are also these methods currently annotated with the old attribute:https://developer.android.com/reference/android/content/pm/PackageManager#addPreferredActivity(android.content.IntentFilter,%20int,%20android.content.ComponentName[],%20android.content.ComponentName)
https://developer.android.com/reference/android/content/pm/PackageManager#getPackageGids(java.lang.String,%20int)
https://developer.android.com/reference/android/content/pm/PackageManager#removePackageFromPreferred(java.lang.String)
https://developer.android.com/reference/android/content/pm/PackageManager#addPackageToPreferred(java.lang.String)
Steps to Reproduce
Did you find any workaround?
No response
Relevant log output
No response