adjust C# win artifact build

tools/run_tests/artifacts/artifact_targets.py

@@ -183,24 +183,14 @@ class CSharpExtArtifact:
     self.labels = ['artifact', 'csharp', platform, arch]
 
   def pre_build_jobspecs(self):
-    if self.platform == 'windows':
-      return [create_jobspec('prebuild_%s' % self.name,
-                             ['tools\\run_tests\\helper_scripts\\pre_build_c.bat'],
-                             shell=True,
-                             flake_retries=5,
-                             timeout_retries=2)]
-    else:
-      return []
+    return []
 
   def build_jobspec(self):
     if self.platform == 'windows':
-      msbuild_platform = 'Win32' if self.arch == 'x86' else self.arch
+      cmake_arch_option = 'Win32' if self.arch == 'x86' else self.arch
       return create_jobspec(self.name,
                             ['tools\\run_tests\\artifacts\\build_artifact_csharp.bat',
-                             'vsprojects\\grpc_csharp_ext.sln',
-                             '/p:Configuration=Release',
-                             '/p:PlatformToolset=v120',
-                             '/p:Platform=%s' % msbuild_platform],
+                             cmake_arch_option],
                             shell=True)
     else:
       environ = {'CONFIG': 'opt',

tools/run_tests/artifacts/build_artifact_csharp.bat

@@ -29,10 +29,16 @@
 
 @rem Builds C# artifacts on Windows
 
-@call vsprojects\build_vs2013.bat %* || goto :error
+set ARCHITECTURE=%1
+
+@call tools\run_tests\helper_scripts\pre_build_csharp.bat %ARCHITECTURE% || goto :error
+
+cd cmake\build\%ARCHITECTURE%
+cmake --build . --target grpc_csharp_ext --config Release
+cd ..\..\..
 
 mkdir artifacts
-copy /Y vsprojects\Release\grpc_csharp_ext.dll artifacts || copy /Y vsprojects\x64\Release\grpc_csharp_ext.dll artifacts || goto :error
+copy /Y cmake\build\Win32\Release\grpc_csharp_ext.dll artifacts || copy /Y cmake\build\x64\Release\grpc_csharp_ext.dll artifacts || goto :error
 
 goto :EOF