VS错误

Question

我正在尝试创建一个访问SQLite数据库的.NET Standard类库。经过大量研究，我认为Microsoft.Data.Sqlite会效果最好。

但是当调用需要该包的类库方法时，出现以下异常：

无法加载文件或程序集“ Microsoft.Data.Sqlite，版本= 2.1.0.0，文化=中性，PublicKeyToken = adb9793829ddae60”或其依赖项之一。系统找不到指定的文件。

我已经在使用.NET Framework 4.6.2的非常简单的控制台应用程序中隔离了该问题，该应用程序在.NET Standard 2.0类库中调用了该方法。我使用NuGet包管理器将Microsoft.Data.Sqlite 2.1.0添加到类库中。我正在Windows 10上使用Visual Studio Community 2017（版本15.8.3）。

在创建直接使用Microsoft.Data.Sqlite的.NET Core 2.1控制台应用程序时，我没有任何问题（也就是说，没有单独的.NET Standard类库）。

关于堆栈溢出的最接近的问题如下，但是它不能解决我的问题：

Exception while loading assemblies: Could not load assembly 'Microsoft.Data.Sqlite'

此问题的上下文是我正在尝试为Windows和Mac创建桌面应用程序。我的希望是使用SQLite作为实际数据库创建一个.NET Standard类库来处理数据访问。我愿意接受其他建议。

Answer 1

这似乎是Visual Studio 和Microsoft.Data.Sqlite包中的的错误

我有一个课程库

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>netstandard2.0</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.Data.Sqlite" Version="2.1.0" />
  </ItemGroup>

</Project>

和3个引用该类库的项目文件

第一

<?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>{8DA91D88-9D79-4F06-BEA4-00C408542D4F}</ProjectGuid>
    <OutputType>Exe</OutputType>
    <RootNamespace>ConsoleApp3</RootNamespace>
    <AssemblyName>ConsoleApp3</AssemblyName>
    <TargetFrameworkVersion>v4.6.2</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>
  <ItemGroup>
    <ProjectReference Include="..\ClassLibrary1\ClassLibrary1.csproj">
      <Project>{eb6c148b-91a1-4f10-8703-2b93af5c4de6}</Project>
      <Name>ClassLibrary1</Name>
    </ProjectReference>
  </ItemGroup>
  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
</Project>

秒：

<?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>{292E456C-AD14-452A-8D12-409157D79673}</ProjectGuid>
    <OutputType>Exe</OutputType>
    <RootNamespace>ConsoleApp2</RootNamespace>
    <AssemblyName>ConsoleApp2</AssemblyName>
    <TargetFrameworkVersion>v4.6.2</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>
  <ItemGroup>
    <ProjectReference Include="..\ClassLibrary1\ClassLibrary1.csproj">
      <Project>{eb6c148b-91a1-4f10-8703-2b93af5c4de6}</Project>
      <Name>ClassLibrary1</Name>
    </ProjectReference>
  </ItemGroup>
  <ItemGroup>
    <PackageReference Include="Newtonsoft.Json">
      <Version>11.0.2</Version>
    </PackageReference>
  </ItemGroup>
  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
</Project>

第三名：

<?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>{FBE757BF-025E-4167-90D0-EAD60E50C7EB}</ProjectGuid>
    <OutputType>Exe</OutputType>
    <RootNamespace>ConsoleApp1</RootNamespace>
    <AssemblyName>ConsoleApp1</AssemblyName>
    <TargetFrameworkVersion>v4.6.2</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>
  <ItemGroup>
    <ProjectReference Include="..\ClassLibrary1\ClassLibrary1.csproj">
      <Project>{eb6c148b-91a1-4f10-8703-2b93af5c4de6}</Project>
      <Name>ClassLibrary1</Name>
    </ProjectReference>
  </ItemGroup>
  <ItemGroup>
    <PackageReference Include="Microsoft.Data.Sqlite">
      <Version>2.1.0</Version>
    </PackageReference>
    <PackageReference Include="Newtonsoft.Json">
      <Version>11.0.2</Version>
    </PackageReference>
  </ItemGroup>
  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
</Project>

第一个项目在您编写时未找到 Microsoft.Data.Sqlite.dll 。
第二项目将找到 Microsoft.Data.Sqlite.dll ，但缺少一些e_sqlite3.dll文件
第三项目将正常运行。

这三个项目之间的区别：

Project1 参考 ClassLibrary1
Project2 引用 ClassLibrary1 和NuGet NewtonSoft.Json
Project3 引用 ClassLibrary1 和NuGet NewtonSoft.Json ， Microsoft.Dara.Sqlite

（ NewtonSoft.Json -您可以使用任何NuGet软件包，只要您引用了NuGet软件包并使用 PackageReference ）。

VS错误

如果您没有通过PackageReference添加对任何NuGet包的引用，则该项目将不包括所包含项目中的任何NuGet包引用

Microsoft.Data.Sqlite

仅当应用程序项目直接引用该软件包时，才会复制所需的文件x64 / x86 e_sqlite3.dll文件。

Answer 2

我只是通过显式添加使其工作

<PackageReference Include="Microsoft.Data.Sqlite" Version="$(MicrosoftDataSqliteVersion)" />

对于引用您的原始项目的基础项目。 Microsoft.Data.Sqlite 现在被正确引用

.NET Standard类库无法加载文件或程序集Microsoft.Data.Sqlite

2 个答案:

VS错误

Microsoft.Data.Sqlite