added option to write csproj file on output code

Author: HugoMario

src/main/java/io/swagger/codegen/v3/generators/dotnet/CsharpDotNet2ClientCodegen.java

@@ -9,6 +9,7 @@
 
 public class CsharpDotNet2ClientCodegen extends AbstractCSharpCodegen {
     public static final String CLIENT_PACKAGE = "clientPackage";
+    public static final String USE_CSPROJ_FILE = "useCsProjFile";
     protected String clientPackage = "IO.Swagger.Client";
     protected String apiDocPath = "docs/";
     protected String modelDocPath = "docs/";
@@ -68,6 +69,9 @@ public void processOpts() {
         supportingFiles.add(new SupportingFile("packages.config.mustache", "vendor", "packages.config"));
         supportingFiles.add(new SupportingFile("compile-mono.sh.mustache", "", "compile-mono.sh"));
         supportingFiles.add(new SupportingFile("README.mustache", "", "README.md"));
+        if (additionalProperties.containsKey(USE_CSPROJ_FILE) && Boolean.parseBoolean(additionalProperties.get(USE_CSPROJ_FILE).toString())) {
+            supportingFiles.add(new SupportingFile("csproj.mustache", "", clientPackage + ".csproj"));
+        }
 
     }
 

src/main/resources/handlebars/csharp-dotnet2/csproj.mustache

@@ -0,0 +1,23 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netstandard2.0</TargetFramework>
+    <RootNamespace>{{clientPackage}}</RootNamespace>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <!-- Nuget Package Metadata -->
+    <PackageId>{{packageName}}</PackageId>
+    <PackageVersion>{{packageVersion}}</PackageVersion>
+    <Authors>{{packageAuthors}}</Authors>
+    <Owners>{{packageCompany}}</Owners>
+    <Title>{{packageTitle}}</Title>
+    <Description>{{packageDescription}}</Description>
+    <Copyright>{{packageCopyright}}</Copyright>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Newtonsoft.Json" Version="12.0.1" />
+    <PackageReference Include="RestSharp" Version="105.0.1" />
+  </ItemGroup>
+</Project>