Is there a way to automatically use a separate app.config when building in release mode?
In other words, I want to test with one app.config, and release with another.
Currently, I keep a separate copy called app.config.production, and manually overwrite bin\Release\Application.exe.config after building for release.
Unload the project in Solution Explorer via the context menu.
Edit the .csproj file via the context menu and add this:
<PropertyGroup>
<AppConfig>App.$(Configuration).config</AppConfig>
</PropertyGroup>
A clean solution is to group 2 files App.Debug.config and App.Release.config into App.config and change the good file into App.config depending on the configuration at compile time:
<ItemGroup>
<None Include="App.config" />
<None Include="App.Debug.config">
<DependentUpon>App.config</DependentUpon>
</None>
<None Include="App.Release.config">
<DependentUpon>App.config</DependentUpon>
</None>
</ItemGroup>
<Target Name="SetAppConfig" BeforeTargets="Compile">
<Copy SourceFiles="App.Debug.config" DestinationFiles="App.config" OverwriteReadOnlyFiles="true" Condition=" '$(Configuration)' == 'Debug' " />
<Copy SourceFiles="App.Release.config" DestinationFiles="App.config" OverwriteReadOnlyFiles="true" Condition=" '$(Configuration)' == 'Release' " />
</Target>
With this solution you will get something like this in Visual Studio:
Similar to top answer but with this approach you can see the actual file if preferred and intellisense doesn't complain in csproj file:
<Target Name="SetAppConfig" BeforeTargets="Compile">
<Copy SourceFiles="debug.config" DestinationFiles="app.config" OverwriteReadOnlyFiles="true" Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' " />
<Copy SourceFiles="release.config" DestinationFiles="app.config" OverwriteReadOnlyFiles="true" Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' " />
</Target>