[Android] AddEmbeddedResourceFont Shows Exception Warning in Output Window

[BrundhaVelusamy]

Description:

When registering a custom font as an embedded resource in a MAUI project, the following error appears in the output window when deploying on Android:

java.lang.RuntimeException: Font asset not found Maui Material Assets.ttf

Reference sample:
MauiSampleApplication.zip

However, when we register the custom font as a MauiFont, this warning does not appear. What is the correct way to register custom fonts? Are there any restrictions if we change the MauiFont from Embedded Resources?

[DanTravison]

I see these as well and they appear after calling ContentPage.InitializeComponent.
I have a second page that reports the same after the first call to InitializeComponent.
Navigating to it a second time does not produce the exceptions.

In all cases, I see the following pattern, often multiple times for a page and multiple times for the same font.

All fonts are defined as embedded resources under Resources\Fonts. Changing the location to Resources\Assets doesn't change the behavior.
I don't see the output in Release builds; only Debug.

Exception thrown: 'Java.Lang.RuntimeException' in System.Private.CoreLib.dll
Microsoft.Maui.FontManager: Warning: Unable to load font '/data/user/0/com.codecadence.glyphviewer/cache/opensans-regular.ttf' from assets.

Java.Lang.RuntimeException: Font asset not found /data/user/0/com.codecadence.glyphviewer/cache/opensans-regular.ttf
   at Java.Interop.JniEnvironment.StaticMethods.CallStaticObjectMethod(JniObjectReference type, JniMethodInfo method, JniArgumentValue* args) in /Users/runner/work/1/s/xamarin-android/external/Java.Interop/src/Java.Interop/obj/Release/net8.0/JniEnvironment.g.cs:line 21453
   at Java.Interop.JniPeerMembers.JniStaticMethods.InvokeObjectMethod(String encodedMember, JniArgumentValue* parameters) in /Users/runner/work/1/s/xamarin-android/external/Java.Interop/src/Java.Interop/Java.Interop/JniPeerMembers.JniStaticMethods.cs:line 165
   at Android.Graphics.Typeface.CreateFromAsset(AssetManager mgr, String path) in /Users/runner/work/1/s/xamarin-android/src/Mono.Android/obj/Release/net9.0/android-35/mcw/Android.Graphics.Typeface.cs:line 637
   at Microsoft.Maui.FontManager.LoadTypefaceFromAsset(String fontfamily, Boolean warning) in /_/src/Core/src/Fonts/FontManager.Android.cs:line 133
  --- End of managed Java.Lang.RuntimeException stack trace ---
java.lang.RuntimeException: Font asset not found /data/user/0/com.codecadence.glyphviewer/cache/opensans-regular.ttf
	at android.graphics.Typeface.createFromAsset(Typeface.java:1044)
	at crc6452ffdc5b34af3a0f.NavigationViewFragment.n_onCreateView(Native Method)
	at crc6452ffdc5b34af3a0f.NavigationViewFragment.onCreateView(NavigationViewFragment.java:39)
	at androidx.fragment.app.Fragment.performCreateView(Fragment.java:3119)
	at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:577)
	at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:286)
	at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:2214)
	at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:2115)
	at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:2052)
	at androidx.fragment.app.FragmentManager.dispatchStateChange(FragmentManager.java:3327)
	at androidx.fragment.app.FragmentManager.dispatchViewCreated(FragmentManager.java:3230)
	at androidx.fragment.app.Fragment.performViewCreated(Fragment.java:3153)
	at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:608)
	at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:286)
	at androidx.fragment.app.FragmentStore.moveToExpectedState(FragmentStore.java:114)
	at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1685)
	at androidx.fragment.app.FragmentManager.dispatchStateChange(FragmentManager.java:3319)
	at androidx.fragment.app.FragmentManager.dispatchViewCreated(FragmentManager.java:3230)
	at androidx.fragment.app.Fragment.performViewCreated(Fragment.java:3153)
	at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:608)
	at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:286)
	at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:2214)
	at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:2115)
	at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:2052)
	at androidx.fragment.app.FragmentManager.dispatchStateChange(FragmentManager.java:3327)
	at androidx.fragment.app.FragmentManager.dispatchActivityCreated(FragmentManager.java:3237)
	at androidx.fragment.app.FragmentController.dispatchActivityCreated(FragmentController.java:263)
	at androidx.fragment.app.FragmentActivity.onStart(FragmentActivity.java:350)
	at androidx.appcompat.app.AppCompatActivity.onStart(AppCompatActivity.java:251)
	at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1543)
	at android.app.Activity.performStart(Activity.java:8330)
	at android.app.ActivityThread.handleStartActivity(ActivityThread.java:3670)
	at android.app.servertransaction.TransactionExecutor.performLifecycleSequence(TransactionExecutor.java:221)
	at android.app.servertransaction.TransactionExecutor.cycleToPath(TransactionExecutor.java:201)
	at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:173)
	at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:97)
	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2307)
	at android.os.Handler.dispatchMessage(Handler.java:106)
	at android.os.Looper.loopOnce(Looper.java:201)
	at android.os.Looper.loop(Looper.java:288)
	at android.app.ActivityThread.main(ActivityThread.java:7872)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:936)

  --- End of managed Java.Lang.RuntimeException stack trace ---
java.lang.RuntimeException: Font asset not found /data/user/0/com.codecadence.glyphviewer/cache/opensans-regular.ttf
	at android.graphics.Typeface.createFromAsset(Typeface.java:1044)
	at crc6452ffdc5b34af3a0f.NavigationViewFragment.n_onCreateView(Native Method)
	at crc6452ffdc5b34af3a0f.NavigationViewFragment.onCreateView(NavigationViewFragment.java:39)
	at androidx.fragment.app.Fragment.performCreateView(Fragment.java:3119)
	at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:577)
	at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:286)
	at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:2214)
	at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:2115)
	at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:2052)
	at androidx.fragment.app.FragmentManager.dispatchStateChange(FragmentManager.java:3327)
	at androidx.fragment.app.FragmentManager.dispatchViewCreated(FragmentManager.java:3230)
	at androidx.fragment.app.Fragment.performViewCreated(Fragment.java:3153)
	at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:608)
	at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:286)
	at androidx.fragment.app.FragmentStore.moveToExpectedState(FragmentStore.java:114)
	at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1685)
	at androidx.fragment.app.FragmentManager.dispatchStateChange(FragmentManager.java:3319)
	at androidx.fragment.app.FragmentManager.dispatchViewCreated(FragmentManager.java:3230)
	at androidx.fragment.app.Fragment.performViewCreated(Fragment.java:3153)
	at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:608)
	at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:286)
	at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:2214)
	at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:2115)
	at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:2052)
	at androidx.fragment.app.FragmentManager.dispatchStateChange(FragmentManager.java:3327)
	at androidx.fragment.app.FragmentManager.dispatchActivityCreated(FragmentManager.java:3237)
	at androidx.fragment.app.FragmentController.dispatchActivityCreated(FragmentController.java:263)
	at androidx.fragment.app.FragmentActivity.onStart(FragmentActivity.java:350)
	at androidx.appcompat.app.AppCompatActivity.onStart(AppCompatActivity.java:251)
	at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1543)
	at android.app.Activity.performStart(Activity.java:8330)
	at android.app.ActivityThread.handleStartActivity(ActivityThread.java:3670)
	at android.app.servertransaction.TransactionExecutor.performLifecycleSequence(TransactionExecutor.java:221)
	at android.app.servertransaction.TransactionExecutor.cycleToPath(TransactionExecutor.java:201)
	at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:173)
	at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:97)
	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2307)
	at android.os.Handler.dispatchMessage(Handler.java:106)
	at android.os.Looper.loopOnce(Looper.java:201)
	at android.os.Looper.loop(Looper.java:288)
	at android.app.ActivityThread.main(ActivityThread.java:7872)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:936)