如何根据所选配置将项目构建为可移植或普通类库

上下文：我们有一个名为"THEPROJECT"的通用库项目，该项目与 Xamarin 移动解决方案和 Visual Studio 中的 Web 项目共享。由于 Xamarin 中的限制，此共享库是 PCL 配置文件 259。在我们的 Web 应用程序解决方案中，我们希望使用适当的属性标记数据模型，以便 DataContext 正常工作(因为我们要使用 LinqToSql(。

尝试的解决方案：我们决定研究"THEPROJECT"的项目，并根据Visual Studio中选定的配置，以一种允许它存在于可移植库/普通类库状态的方式更改msbuild。

我们已经在这篇文章中研究了解决方案，但它只是解决方案的一部分。我们可以让项目作为一个或另一个存在，但是它需要手动更改项目文件。现在我们收到加载以下项目时出错。对于可移植项目，必须为".净值'。

<?xml version="1.0" encoding="utf-8"?>
<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
    <PropertyGroup>
        <Configuration Condition=" '$(Configuration)' == '' ">DebugDesktop</Configuration>
        <Platform Condition="'$(Platform)' == ''">AnyCPU</Platform>
        <ProjectGuid>{426E7BD8-9DA8-4E15-9512-72E7C632B037}</ProjectGuid>
        <OutputType>Library</OutputType>
        <AppDesignerFolder>Properties</AppDesignerFolder>
        <RootNamespace>THEPROJECT</RootNamespace>
        <AssemblyName>THEPROJECT</AssemblyName>
        <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
        <MinimumVisualStudioVersion>10.0</MinimumVisualStudioVersion>
        <BuildMode>Desktop</BuildMode>
    </PropertyGroup>
    <!-- Define the Build Configurations -->
    <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'DebugDesktop|AnyCPU' ">
        <DebugSymbols>true</DebugSymbols>
        <DebugType>full</DebugType>
        <Optimize>false</Optimize>
        <OutputPath>bin'Desktop'Debug'</OutputPath>
        <DefineConstants>TRACE;DEBUG;</DefineConstants>
        <ErrorReport>prompt</ErrorReport>
        <WarningLevel>4</WarningLevel>
        <ConsolePause>false</ConsolePause>
        <BuildMode>Desktop</BuildMode>
    </PropertyGroup>
    <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'ReleaseDesktop|AnyCPU' ">
        <DebugType>pdbonly</DebugType>
        <Optimize>true</Optimize>
        <OutputPath>bin'Desktop'Release'</OutputPath>
        <DefineConstants>TRACE</DefineConstants>
        <ErrorReport>prompt</ErrorReport>
        <WarningLevel>4</WarningLevel>
        <BuildMode>Desktop</BuildMode>
    </PropertyGroup>
    <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'DebugPCL|AnyCPU' ">
        <DebugSymbols>true</DebugSymbols>
        <DebugType>full</DebugType>
        <Optimize>false</Optimize>
        <OutputPath>bin'PCL'Debug'</OutputPath>
        <DefineConstants>TRACE;DEBUG;</DefineConstants>
        <ErrorReport>prompt</ErrorReport>
        <WarningLevel>4</WarningLevel>
        <ConsolePause>false</ConsolePause>
        <BuildMode>Portable</BuildMode>
    </PropertyGroup>
    <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'ReleasePCL|AnyCPU' ">
        <DebugType>pdbonly</DebugType>
        <Optimize>true</Optimize>
        <OutputPath>bin'PCL'Release'</OutputPath>
        <DefineConstants>TRACE</DefineConstants>
        <ErrorReport>prompt</ErrorReport>
        <WarningLevel>4</WarningLevel>
        <BuildMode>Portable</BuildMode>
    </PropertyGroup>
    <!-- Determine the correct properties for PCL/Desktop -->
    <Choose>
        <When Condition=" '$(BuildMode)' == 'Portable' ">
            <PropertyGroup>
                <ProjectTypeGuids>{786C830F-07A1-408B-BD7F-6EE04809D6DB};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
                <TargetFrameworkProfile>Profile259</TargetFrameworkProfile>
                <TargetFrameworkIdentifier>.NETPortable</TargetFrameworkIdentifier>
                <DynamicImportPath>$(MSBuildExtensionsPath32)'Microsoft'Portable'$(TargetFrameworkVersion)'Microsoft.Portable.CSharp.targets</DynamicImportPath>
            </PropertyGroup>
        </When>
        <When Condition=" '$(BuildMode)' == 'Desktop' ">
            <PropertyGroup>
                <FileAlignment>512</FileAlignment>
                <TargetFrameworkProfile />
                <DynamicImportPath>$(MSBuildToolsPath)'Microsoft.CSharp.targets</DynamicImportPath>
            </PropertyGroup>
            <ItemGroup>
                <Reference Include="System.Data.Linq" />
            </ItemGroup>
        </When>
    </Choose>
    <ItemGroup>
        <Reference Include="Newtonsoft.Json, Version=8.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed, processorArchitecture=MSIL">
            <HintPath>..'..'mobileapplication'packages'Newtonsoft.Json.8.0.2'lib'portable-net40+sl5+wp80+win8+wpa81'Newtonsoft.Json.dll</HintPath>
            <Private>True</Private>
        </Reference>
        <Reference Include="System" />
        <Reference Include="System.Core" />
        <Reference Include="System.Xml.Linq" />
        <Reference Include="Microsoft.CSharp" />
        <Reference Include="System.Xml" />
    </ItemGroup>
    <ItemGroup>
        <ProjectReference Include="..'..'sqlite-net-extensions'SQLiteNetExtensions'SQLiteNetExtensions-PCL.csproj">
            <Project>{f723017d-ede5-49cc-a84f-881c067c6004}</Project>
            <Name>SQLiteNetExtensions-PCL</Name>
        </ProjectReference>
        <ProjectReference Include="..'..'sqlitenetpcl'src'SQLite.Net'SQLite.Net.csproj">
            <Project>{4971d437-0694-4297-a8cc-146ce08c3bd9}</Project>
            <Name>SQLite.Net</Name>
        </ProjectReference>
    </ItemGroup>
    <Import Project="$(DynamicImportPath)" />
    <!-- Source/Resx etc... -->
</Project>