Move hardcoded error strings in JCWGenerator.cs to Properties.Resources with XA error codes

Documentation/docs-mobile/messages/index.md

@@ -184,6 +184,7 @@ Either change the value in the AndroidManifest.xml to match the $(SupportedOSPla
 + [XA4215](xa4215.md): The Java type \`com.contoso.library1.Class1\` is generated by more than one managed type. Please change the \[Register\] attribute so that the same Java type is not emitted.
 + [XA4216](xa4216.md): The deployment target '19' is not supported (the minimum is '21'). Please increase the $(SupportedOSPlatformVersion) property value in your project file.
 + XA4217: Cannot override Kotlin-generated method '{method}' because it is not a valid Java method name. This method can only be overridden from Kotlin.
++ [XA4217](xa4217.md): Architecture '{arch}' has Java types which have no counterparts in template architecture '{templateArch}': {types}
 + [XA4218](xa4218.md): Unable to find //manifest/application/uses-library at path: {path}
 + XA4219: Cannot find binding generator for language {language} or {defaultLanguage}.
 + XA4220: Partial class item '{file}' does not have an associated binding for layout '{layout}'.
@@ -193,6 +194,7 @@ Either change the value in the AndroidManifest.xml to match the $(SupportedOSPla
 + XA4224: Malformed full class name '{name}'. Missing class name.
 + XA4225: Widget '{widget}' in layout '{layout}' has multiple instances with different types. The property type will be set to: {type}
 + XA4226: Resource item '{file}' does not have the required metadata item '{metadataName}'.
++ [XA4227](xa4227.md): Architecture '{arch}' doesn't match all marshal methods in architecture '{templateArch}'. Please see detailed MSBuild logs for more information.
 + XA4228: Unable to find specified //activity-alias/@android:targetActivity: '{targetActivity}'
 + XA4229: Unrecognized \`TransformFile\` root element: {element}.
 + XA4230: Error parsing XML: {exception}
@@ -214,6 +216,7 @@ Either change the value in the AndroidManifest.xml to match the $(SupportedOSPla
 + [XA4235](xa4249.md): Maven artifact specification '{artifact}' is invalid. The correct format is 'group_id:artifact_id:version'.
 + [XA4250](xa4250.md): Manifest-referenced type '{type}' was not found in any scanned assembly. It may be a framework type.
 + [XA4252](xa4252.md): Insecure HTTP Maven repository URL '{url}' is not allowed. Use an HTTPS URL, or set AllowInsecureHttp="true" metadata on the item to override this check.
++ [XA4253](xa4253.md): Generated Java callable wrapper code changed: '{path}'
 + XA4300: Native library '{library}' will not be bundled because it has an unsupported ABI.
 + [XA4301](xa4301.md): Apk already contains the item `xxx`.
 + [XA4302](xa4302.md): Unhandled exception merging \`AndroidManifest.xml\`: {ex}

Documentation/docs-mobile/messages/xa4217.md

@@ -0,0 +1,29 @@
+---
+title: .NET for Android error XA4217
+description: XA4217 error code
+ms.date: 05/20/2026
+f1_keywords:
+  - "XA4217"
+---
+
+# .NET for Android error XA4217
+
+## Example messages
+
+```
+error XA4217: Architecture 'x86' has Java types which have no counterparts in template architecture 'arm64-v8a': MyNamespace.MyType
+```
+
+## Issue
+
+When building for multiple Android architectures, each architecture must
+produce the same set of Java callable wrapper types. This error means
+one architecture generated Java types that do not exist in the template
+(first) architecture.
+
+## Solution
+
+Ensure that all target architectures reference the same set of managed
+types that derive from `Java.Lang.Object`. If architecture-specific
+code is needed, use runtime checks rather than conditional compilation
+that adds or removes Java-bound types per architecture.

Documentation/docs-mobile/messages/xa4227.md

@@ -0,0 +1,29 @@
+---
+title: .NET for Android error XA4227
+description: XA4227 error code
+ms.date: 05/20/2026
+f1_keywords:
+  - "XA4227"
+---
+
+# .NET for Android error XA4227
+
+## Example messages
+
+```
+error XA4227: Architecture 'x86' doesn't match all marshal methods in architecture 'arm64-v8a'. Please see detailed MSBuild logs for more information.
+```
+
+## Issue
+
+When building for multiple Android architectures, the marshal methods
+generated for each architecture must be consistent. This error means
+one architecture has marshal methods that do not match those of the
+template (first) architecture.
+
+## Solution
+
+Ensure that all target architectures reference the same set of managed
+types and methods. Enable detailed MSBuild logging (`-v:diag`) to see
+exactly which marshal methods differ, then adjust the project so that
+all architectures produce the same set of marshal methods.

Documentation/docs-mobile/messages/xa4253.md

@@ -0,0 +1,28 @@
+---
+title: .NET for Android error XA4253
+description: XA4253 error code
+ms.date: 05/20/2026
+f1_keywords:
+  - "XA4253"
+---
+
+# .NET for Android error XA4253
+
+## Example messages
+
+```
+error XA4253: Generated Java callable wrapper code changed: 'obj/Release/android/src/mono/MonoRuntimeProvider.java'
+```
+
+## Issue
+
+The generated Java callable wrapper (JCW) source file was unexpectedly
+modified during the build. This usually indicates that an incremental
+build detected a change in the generated output that should not have
+occurred.
+
+## Solution
+
+Perform a clean build of your project (`dotnet clean` followed by
+`dotnet build`) to ensure all generated files are up to date. If the
+error persists, please file a bug report with a reproduction project.

src/Xamarin.Android.Build.Tasks/Properties/Resources.resx

@@ -650,6 +650,12 @@ Either change the value in the AndroidManifest.xml to match the $(SupportedOSPla
     <comment>The following are literal names and should not be translated: AndroidManifest.xml, //uses-sdk/@android:targetSdkVersion , API-{1}
 {0} - The target SDK version number
 {1} - The API version number</comment>
+  </data>
+  <data name="XA4217" xml:space="preserve">
+    <value>Architecture '{0}' has Java types which have no counterparts in template architecture '{1}': {2}</value>
+    <comment>{0} - The target architecture name
+{1} - The template architecture name
+{2} - Comma-separated list of Java type names that have no counterparts</comment>
   </data>
   <data name="XA4218" xml:space="preserve">
     <value>Unable to find //manifest/application/uses-library at path: {0}</value>
@@ -701,6 +707,11 @@ In this mesage, the term "layout" means an Android UI layout.
     <value>Resource item '{0}' does not have the required metadata item '{1}'.</value>
     <comment>{0} - The name of the Android layout resource file
 {1} - The name of the metadata item</comment>
+  </data>
+  <data name="XA4227" xml:space="preserve">
+    <value>Architecture '{0}' doesn't match all marshal methods in architecture '{1}'. Please see detailed MSBuild logs for more information.</value>
+    <comment>{0} - The target architecture name
+{1} - The template architecture name</comment>
   </data>
   <data name="XA4228" xml:space="preserve">
     <value>Unable to find specified //activity-alias/@android:targetActivity: '{0}'</value>
@@ -1112,6 +1123,10 @@ To use a custom JDK path for a command line build, set the 'JavaSdkDirectory' MS
     <comment>The following are literal names and should not be translated: HTTP, HTTPS, Maven, AllowInsecureHttp
 {0} - The insecure HTTP URL</comment>
   </data>
+  <data name="XA4253" xml:space="preserve">
+    <value>Generated Java callable wrapper code changed: '{0}'</value>
+    <comment>{0} - The path to the generated Java callable wrapper file</comment>
+  </data>
   <data name="XA0142" xml:space="preserve">
     <value>Command '{0}' failed.\n{1}</value>
     <comment>'{0}' is a failed command name (potentially with path) followed by all the arguments passed to it. {1} is the combined output on the standard error and standard output streams.</comment>

src/Xamarin.Android.Build.Tasks/Utilities/JCWGenerator.cs

@@ -107,7 +107,7 @@ public bool GenerateCode (CallableWrapperType generator, TypeDefinition type, st
 			var changed = Files.CopyIfStreamChanged (writer.BaseStream, path);
 
 			if (changed) {
-				log.LogError ($"Generated Java callable wrapper code changed: '{path}' ");
+				log.LogCodedError ("XA4253", Properties.Resources.XA4253, path);
 			} else {
 				log.LogMessage ($"Java callable wrapper code already up to date: '{path}'");
 			}
@@ -188,12 +188,9 @@ static void EnsureIdenticalCollections (TaskLoggingHelper logger, NativeCodeGenS
 		}
 
 		if (!typesSet.SetEquals (templateSet)) {
-			logger.LogError ($"Architecture '{state.TargetArch}' has Java types which have no counterparts in template architecture '{templateState.TargetArch}':");
-
 			typesSet.ExceptWith (templateSet);
-
-			foreach (var type in typesSet)
-				logger.LogError ($"  {type}");
+			var typesList = string.Join (", ", typesSet.OrderBy (t => t, StringComparer.Ordinal));
+			logger.LogCodedError ("XA4217", Properties.Resources.XA4217, state.TargetArch, templateState.TargetArch, typesList);
 		}
 	}
 
@@ -268,7 +265,7 @@ static void EnsureClassifiersMatch (TaskLoggingHelper logger, NativeCodeGenState
 			return;
 		}
 
-		logger.LogError ($"Architecture '{state.TargetArch}' doesn't match all marshal methods in architecture '{templateState.TargetArch}'. Please see detailed MSBuild logs for more information.");
+		logger.LogCodedError ("XA4227", Properties.Resources.XA4227, state.TargetArch, templateState.TargetArch);
 	}
 
 	static bool CheckWhetherMethodsMatch (TaskLoggingHelper logger, MarshalMethodEntry templateMethod, AndroidTargetArch templateArch, MarshalMethodEntry method, AndroidTargetArch arch)