Added a function to RenderTargetBitmap to create a DrawingContext for editing the current image data and not clearing it.

api/Avalonia.nupkg.xml

@@ -1,12 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!-- https://learn.microsoft.com/en-us/dotnet/fundamentals/package-validation/diagnostic-ids -->
 <Suppressions xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
-  <Suppression>
-    <DiagnosticId>CP0002</DiagnosticId>
-    <Target>M:Avalonia.Media.Imaging.RenderTargetBitmap.CreateDrawingContext</Target>
-    <Left>baseline/netstandard2.0/Avalonia.Base.dll</Left>
-    <Right>target/netstandard2.0/Avalonia.Base.dll</Right>
-  </Suppression>
   <Suppression>
     <DiagnosticId>CP0006</DiagnosticId>
     <Target>P:Avalonia.Rendering.Composition.ICompositionGpuImportedObject.ImportCompleted</Target>

src/Avalonia.Base/Media/Imaging/RenderTargetBitmap.cs

@@ -63,15 +63,24 @@ namespace Avalonia.Media.Imaging
         }
 
         /// <summary>
-        /// Creates a <see cref="DrawingContext"/> for drawing to the <see cref="RenderTargetBitmap"/>.
+        /// Creates a <see cref="DrawingContext"/> for drawing to the <see cref="RenderTargetBitmap"/>. 
+        /// Clears the current image data to transparent.
         /// </summary>
-        /// <param name="clear">Indicates if the image should be cleared.</param>
         /// <returns>The drawing context.</returns>
-        public DrawingContext CreateDrawingContext(bool clear = true)
+        public DrawingContext CreateDrawingContext()
+        {
+            var platform = PlatformImpl.Item.CreateDrawingContext();
+            platform.Clear(Colors.Transparent);
+            return new PlatformDrawingContext(platform);
+        }
+
+        /// <summary>
+        /// Creates a <see cref="DrawingContext"/> for editing the already existing image in the <see cref="RenderTargetBitmap"/>.
+        /// </summary>
+        /// <returns>The drawing context.</returns>
+        public DrawingContext CreateEditDrawingContext()
         {
             var platform = PlatformImpl.Item.CreateDrawingContext();
-            if(clear)
-                platform.Clear(Colors.Transparent);
             return new PlatformDrawingContext(platform);
         }