找不到元数据文件.dll

Question

My project can't find the namespaces. Does someone know what the problem is?

I have tried a lot of option to fix the problem. But not one of them works.

I have tried: clean solution, build solution, refactor and

Right click on the solution and click Properties.

Click Configuration on the left.

Make sure the check box under Build for the project it can't find is checked.

If it is already checked, uncheck, hit apply and check the boxes again.

Here is a screenshot of my code. screenshot of code

    <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>{DD7D144A-06C0-482A-9142-3CD989CCC7A4}</ProjectGuid>
        <OutputType>Library</OutputType>
        <AppDesignerFolder>Properties</AppDesignerFolder>
        <RootNamespace>NTier.BLL</RootNamespace>
        <AssemblyName>NTier.BLL</AssemblyName>
        <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
        <FileAlignment>512</FileAlignment>
      </PropertyGroup>
      <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">

        <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' ">

        <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="Admin\AdminLogic.cs" />
        <Compile Include="Customer\CustomerLogic.cs" />
        <Compile Include="Admin\IAdminLogic.cs" />
        <Compile Include="Customer\ICustomerLogic.cs" />
        <Compile Include="Customer\INotRegularCustomerLogic.cs" />
        <Compile Include="Customer\IRegularCustomerLogic.cs" />
        <Compile Include="Customer\NotRegularCustomerLogic.cs" />
        <Compile Include="Customer\RegularCustomerLogic.cs" />
        <Compile Include="Order\IOrderLogic.cs" />
        <Compile Include="Order\OrderLogic.cs" />
        <Compile Include="Product\IProductLogic.cs" />
        <Compile Include="Review\IReviewLogic.cs" />
        <Compile Include="Product\ProductLogic.cs" />
        <Compile Include="Properties\AssemblyInfo.cs" />
        <Compile Include="Review\ReviewLogic.cs" />
      </ItemGroup>
      <ItemGroup>
        <ProjectReference Include="..\NTier.DAL\NTier.DAL.csproj">

          <Project>{a42bdcd5-0ec1-4d2a-b96a-92e39138e9cb}</Project>
          <Name>NTier.DAL</Name>
        </ProjectReference>
        <ProjectReference Include="..\NTier.Domain\NTier.Domain.csproj">
          <Project>{70a4d682-67bb-456b-a21d-f343b43fe1b6}</Project>
          <Name>NTier.Domain</Name>
        </ProjectReference>
      </ItemGroup>
      <ItemGroup>
        <WCFMetadata Include="Connected Services\" />
      </ItemGroup>
      <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
    </Project>

Here is the code that you asked for. Hopefully you can help with my problem.

Answer 1

The reason is conflict between your namespace in ProductLogic class and the name of Product class from NTier.Domain namespace. It has not much to do with the project reference. In this case VS has priority over current namespace, not class from other namespace. You need to use NTier.Domain.Product each time for each Product class usage in that case or change your NTier.BLL.Product Namespace to something else; for instance NTier.BLL.ProductLogic

It also doesn't seem true you "can't" use Ntier.Domain namespace (referring to the screenshot attached and comment in there): it's grayed out because it is not used at all (as VS doesn't connect any of Product strings used in code to the class you would like it to do, but to current namespace, so none of classes from Ntier.Domain is used and VS says you "you can remove that reference, it's not used"), to check that: if you put our mouse over Product reference you should see something like that:

which informs you that VS is not seeing a class there, but your current namespace