Move hardcoded warning strings in MergeRemapXml to Properties.Resources with XA codes

Documentation/docs-mobile/messages/index.md

@@ -233,6 +233,9 @@ Either change the value in the AndroidManifest.xml to match the $(SupportedOSPla
 + [XA4313](xa4313.md): Framework assembly has been deprecated.
 + [XA4314](xa4314.md): `$(Property)` is empty. A value for `$(Property)` should be provided.
 + [XA4315](xa4315.md): Ignoring {file}. Manifest does not have the required 'package' attribute on the manifest element.
++ [XA4316](xa4316.md): Specified input file '{file}' does not exist. Ignoring.
++ [XA4317](xa4317.md): Input file '{file}' does not start with `<replacements/>`. Skipping.
++ [XA4318](xa4318.md): Input file '{file}' could not be read: {message}. Skipping.
 
 ## XA5xxx: GCC and toolchain
 

Documentation/docs-mobile/messages/xa4316.md

@@ -0,0 +1,25 @@
+---
+title: .NET for Android warning XA4316
+description: XA4316 warning code
+ms.date: 05/22/2026
+f1_keywords:
+  - "XA4316"
+---
+
+# .NET for Android warning XA4316
+
+## Example messages
+
+```
+warning XA4316: Specified input file '{file}' does not exist. Ignoring.
+```
+
+## Issue
+
+A remap XML input file specified via the `InputRemapXmlFiles` item group does
+not exist on disk. The file is ignored and the build continues.
+
+## Solution
+
+Verify that the file path is correct and that the file exists. Remove the
+reference if the file is no longer needed.

Documentation/docs-mobile/messages/xa4317.md

@@ -0,0 +1,31 @@
+---
+title: .NET for Android warning XA4317
+description: XA4317 warning code
+ms.date: 05/22/2026
+f1_keywords:
+  - "XA4317"
+---
+
+# .NET for Android warning XA4317
+
+## Example messages
+
+```
+warning XA4317: Input file '{file}' does not start with '<replacements/>'. Skipping.
+```
+
+## Issue
+
+A remap XML input file does not have `<replacements>` as its root element.
+Files passed to the remap XML merge must use the `<replacements>` root element.
+
+## Solution
+
+Ensure the XML file has the correct format with `<replacements>` as the root
+element:
+
+```xml
+<replacements>
+  <!-- replacement entries here -->
+</replacements>
+```

Documentation/docs-mobile/messages/xa4318.md

@@ -0,0 +1,26 @@
+---
+title: .NET for Android warning XA4318
+description: XA4318 warning code
+ms.date: 05/22/2026
+f1_keywords:
+  - "XA4318"
+---
+
+# .NET for Android warning XA4318
+
+## Example messages
+
+```
+warning XA4318: Input file '{file}' could not be read: {message}. Skipping.
+```
+
+## Issue
+
+A remap XML input file could not be read, for example because it contains
+invalid XML or there is a permissions issue. The file is skipped and the build
+continues.
+
+## Solution
+
+Verify that the file contains valid XML and that the build process has
+permission to read it.

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

@@ -836,6 +836,22 @@ Remove the '{0}' reference from your project and add the '{1}' NuGet package ins
   <data name="XA4315" xml:space="preserve">
     <value>Ignoring `{0}`. Manifest does not have the required 'package' attribute on the manifest element.</value>
     <comment>{0} - The path the the file.
+</comment>
+  </data>
+  <data name="XA4316" xml:space="preserve">
+    <value>Specified input file '{0}' does not exist. Ignoring.</value>
+    <comment>{0} - The path to the file.
+</comment>
+  </data>
+  <data name="XA4317" xml:space="preserve">
+    <value>Input file '{0}' does not start with '&lt;replacements/&gt;'. Skipping.</value>
+    <comment>{0} - The path to the file.
+</comment>
+  </data>
+  <data name="XA4318" xml:space="preserve">
+    <value>Input file '{0}' could not be read: {1}. Skipping.</value>
+    <comment>{0} - The path to the file.
+{1} - The exception message.
 </comment>
   </data>
   <data name="XA5101" xml:space="preserve">

src/Xamarin.Android.Build.Tasks/Tasks/MergeRemapXml.cs

@@ -53,7 +53,7 @@ public override bool RunTask ()
 		void MergeInputFile (XmlWriter writer, string file)
 		{
 			if (!File.Exists (file)) {
-				Log.LogWarning ($"Specified input file `{file}` does not exist.  Ignoring.");
+				Log.LogCodedWarning ("XA4316", Properties.Resources.XA4316, file);
 				return;
 			}
 			var settings    = new XmlReaderSettings {
@@ -65,7 +65,7 @@ void MergeInputFile (XmlWriter writer, string file)
 					return;
 				}
 				if (reader.LocalName != "replacements") {
-					Log.LogWarning ($"Input file `{file}` does not start with `<replacements/>`.  Skipping.");
+					Log.LogCodedWarning ("XA4317", Properties.Resources.XA4317, file);
 					return;
 				}
 				while (reader.Read ()) {
@@ -76,7 +76,7 @@ void MergeInputFile (XmlWriter writer, string file)
 				}
 			}
 			catch (Exception e) {
-				Log.LogWarning ($"Input file `{file}` could not be read: {e.Message}  Skipping.");
+				Log.LogCodedWarning ("XA4318", Properties.Resources.XA4318, file, e.Message);
 				Log.LogDebugMessage ($"Input file `{file}` could not be read: {e.ToString ()}");
 			}
 		}