Merge pull request #13 from Taylormsz/aspnet48compat

compat doc for bug#563497

Author: Unity-Billal-mesloub

Documentation/compatibility/aspnet-ASP.NET ValidationContext.MemberName is null sometimes.md

@@ -0,0 +1,34 @@
+## ASP.NET ValidationContext.MemberName is not NULL when using custom DataAnnotations.ValidationAttribute
+
+### Version Introduced
+4.8
+
+### Change Description
+When using custom `DataAnnotations.ValidationAttribute`, `System.ComponentModel.DataAnnotations.ValidationContext.MemberName` returns null.  This issue is fixed in .NET 4.8.
+
+
+### Recommended Action
+Starting from .NET 4.8, the default behavior stays the same.  Please use the following appsettings to retrieve valud of `ValidationContext.MemberName` property:
+
+```xml
+    <configuration>
+      <appSettings>
+      ...
+        <add key="aspnet:GetValidationMemberName"  value="true"/>
+      ...
+      </appSettings>
+    </configuration>
+```
+
+### Affected APIs
+`System.ComponentModel.DataAnnotations.ValidationContext.MemberName`
+
+### Category
+ASP.NET
+
+<!--
+    ### 563497	<ASP.NET WebForms> ValidationContext.MemberName is NULL with custom DataAnnotations.ValidationAttribute
+
+-->
+
+