[Breaking change]: WCF Client 6.0 release will no longer support net standard 2.0

[HongGit]

Description

WCF Client 6.0 release will no longer support net standard 2.0. WCF Client 6.0 will move to target .NET 6.0.

WCF Client releases used to support net standard 2.0, in order to support both .NET core and .NET Framework. This helps developers to modernize their existing WCF applications from .NET Framework to .NET Core. It's time for WCF Client to take a step further in order to catch up with other .NET Core frameworks, so WCF Client and WCF Client applications could take advantage of new features and APIs available on .NET 6.0.

Version

Other (please put exact version in description textbox)

We will release preview next week, RTM date is not decided yet.

Previous behavior

Developer could add a package reference to WCF Client Nuget packages regardless of its target framework. When targeting or running .NET Framework, it is always used System.ServiceModel.dll implementation in the .NET Framework.

New behavior

WCF Client Nuget packages targets only .NET 6.0. Library project targeting net standard 2.0 which referenced WCF Client packages will now need to multi-target .NET Framework and .NET with conditional assembly reference to System.ServiceModel for .NET Framework and conditionally add package references to WCF Client packages for .NET.

In addition, System.ServiceModel.Duplex and System.ServiceModel.Security packages are deprecated, and this is the last release for these two Nuget packages. The types have been moved to System.ServiceModel.Primitives, these final packages will type forward the types to System.ServiceModel.Primitives for binary compatibility.

Type of breaking change

• Binary incompatible: Existing binaries may encounter a breaking change in behavior, such as failure to load or execute, and if so, require recompilation.
• Source incompatible: When recompiled using the new SDK or component or to target the new runtime, existing source code may require source changes to compile successfully.
• Behavioral change: Existing binaries may behave differently at run time.

Reason for change

WCF Client releases used to support net standard 2.0, in order to support both .NET core and .NET Framework. This helps developers to modernize their existing WCF applications from .NET Framework to .NET Core. It's time for WCF Client to take a step further in order to catch up with other .NET Core frameworks, so WCF Client and WCF Client applications could take advantage of new features and APIs available on .NET 6.0.

With this change, WCF Client Nuget packages are smaller, so the footprint is smaller during deployment.

Recommended action

If WCF projects targets 6.0 or later, no change is needed. If targeting net standard 2.0, then you will need to multi-targeting your WCF libraries. If you are referencing System.ServiceModel.Duplex and System.ServiceModel.Security, remove these package references, they are no longer needed.

Feature area

WCF Client

Affected APIs

NA

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Associated WorkItem - 59714