Search code examples
c#visual-studio-2017resharperdebuggerdisplay

DebuggerDisplayAttribute has no effect in VS 2017

It seems like the DebuggerDisplayAttribute is not having any effect in Visual Studio 2017 (15.9.4) with Resharper 2018.2.3.

  • Placing the attribute in AssemblyInfo.cs, or in Program.cs, has no discernible effect.
  • I am targeting .Net Framework 4.7.2. Changing the framework version also has no discernible effect.
  • I have verified that "Show raw structure of objects in variables windows" is unchecked in Tools -> Options -> Debugging -> General. I even checked it, closed VS, reopened VS, and unchecked it, just to be sure. No effect.

enter image description here

  • Placing the attribute on a custom class does have an effect. It seems that the attribute is only being ignored when at the assembly level.
  • This works as expected in VS 2015 (with the same version of Resharper).
  • Starting VS 2017 in safe mode (using devenv.exe /safemode) has no effect.
  • Updating VS 15.9.4 -> 15.9.7 has no effect.

Here is a very basic console application. Despite the attribute, the dt variable appears as {2/14/2019 10:35:38 AM} in my watch window.
enter image description here

[assembly: DebuggerDisplay("Foo", Target = typeof(DateTime))]

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            var dt = DateTime.Now;
            Debugger.Break();
        }
    }
}

If I use ILSpy to decompile my console application, I can see these attributes applied:

[assembly: Debuggable(
    DebuggableAttribute.DebuggingModes.Default | 
    DebuggableAttribute.DebuggingModes.DisableOptimizations | 
    DebuggableAttribute.DebuggingModes.IgnoreSymbolStoreSequencePoints | 
    DebuggableAttribute.DebuggingModes.EnableEditAndContinue)]
[assembly: DebuggerDisplay("Foo", Target = typeof(DateTime))]

Why isn't the attribute doing anything? How do I even begin to debug this?

Edit: Complete source files as requested.

ConsoleApp1.csproj

<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
  <PropertyGroup>
    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
    <ProjectGuid>{EBBA72C6-5087-4D8E-9F2C-B968ABD59EAA}</ProjectGuid>
    <OutputType>Exe</OutputType>
    <RootNamespace>ConsoleApp1</RootNamespace>
    <AssemblyName>ConsoleApp1</AssemblyName>
    <TargetFrameworkVersion>v4.7.2</TargetFrameworkVersion>
    <FileAlignment>512</FileAlignment>
    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
    <Deterministic>true</Deterministic>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
    <PlatformTarget>AnyCPU</PlatformTarget>
    <DebugSymbols>true</DebugSymbols>
    <DebugType>full</DebugType>
    <Optimize>false</Optimize>
    <OutputPath>bin\Debug\</OutputPath>
    <DefineConstants>DEBUG;TRACE</DefineConstants>
    <ErrorReport>prompt</ErrorReport>
    <WarningLevel>4</WarningLevel>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
    <PlatformTarget>AnyCPU</PlatformTarget>
    <DebugType>pdbonly</DebugType>
    <Optimize>true</Optimize>
    <OutputPath>bin\Release\</OutputPath>
    <DefineConstants>TRACE</DefineConstants>
    <ErrorReport>prompt</ErrorReport>
    <WarningLevel>4</WarningLevel>
  </PropertyGroup>
  <ItemGroup>
    <Reference Include="System" />
    <Reference Include="System.Core" />
    <Reference Include="System.Xml.Linq" />
    <Reference Include="System.Data.DataSetExtensions" />
    <Reference Include="Microsoft.CSharp" />
    <Reference Include="System.Data" />
    <Reference Include="System.Net.Http" />
    <Reference Include="System.Xml" />
  </ItemGroup>
  <ItemGroup>
    <Compile Include="Program.cs" />
    <Compile Include="Properties\AssemblyInfo.cs" />
  </ItemGroup>
  <ItemGroup>
    <None Include="App.config" />
  </ItemGroup>
  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
</Project>

app.config:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <startup> 
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.7.2" />
    </startup>
</configuration>

AssemblyInfo.cs:

using System.Reflection;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
[assembly: AssemblyTitle("ConsoleApp1")]
[assembly: AssemblyDescription("")]
[assembly: AssemblyConfiguration("")]
[assembly: AssemblyCompany("")]
[assembly: AssemblyProduct("ConsoleApp1")]
[assembly: AssemblyCopyright("Copyright ©  2019")]
[assembly: AssemblyTrademark("")]
[assembly: AssemblyCulture("")]
[assembly: ComVisible(false)]
[assembly: Guid("ebba72c6-5087-4d8e-9f2c-b968abd59eaa")]
[assembly: AssemblyVersion("1.0.0.0")]
[assembly: AssemblyFileVersion("1.0.0.0")]
Solution

  • I've built the project from the sources you provided, and can't reproduce the problem:

    debugger display

    This means that on the fresh installation of VS 2017 the feature must work. So your installation of Visual Studio must be somehow corrupt.

    After investigation in comments I'd suggest to do an installation repair, it should fix the problems.