启用PublishSingleFile时SQLite连接抛空参数异常求助

将应用打包为单文件后，运行生成的exe时持续抛出如下异常：

Value cannot be null. (Parameter 'path1')

System.Private.CoreLib
at System.IO.Path.Combine(String path1, String path2)
at System.Data.SQLite.SQLiteConnection..ctor(String connectionString, Boolean parseViaFramework)
at System.Data.SQLite.SQLiteConnection..ctor(String connectionString)
at OrderManager.Program.Main() in C:\Users\Documents\GitHub\OrderManager\Program.cs:line 52

对应的代码片段：

51. File.AppendAllText(AppContext.BaseDirectory + @"\log.txt", ProgramParameters.connectionStringAdmin + Environment.NewLine);
52. connection = new(ProgramParameters.connectionStringAdmin);

已确认ProgramParameters.connectionStringAdmin内容正确：

Data Source = C:\Users\Documents\GitHub\OrderManager\bin\Release\net6.0-windows10.0.22621.0\publish\db\ManagerOrdini.db ; cache=shared; synchronous  = NORMAL ;  journal_mode=WAL; temp_store = memory;  mmap_size = 30000000000; 

Debug和Release模式下应用运行正常，无报错。已尝试在.csproj中设置排除System.Data.SQLite包的单文件嵌入，但无效：

<PropertyGroup>
    <ApplicationIcon>icon.ico</ApplicationIcon>
    <OutputType>WinExe</OutputType>
    
    <EmbedInteropTypes>True</EmbedInteropTypes>
    <_SuppressWinFormsTrimError>true</_SuppressWinFormsTrimError>
    <CustomResourceTypesSupport>true</CustomResourceTypesSupport>
    <BuiltInComInteropSupport>true</BuiltInComInteropSupport>
    <RuntimeIdentifier>win-x64</RuntimeIdentifier>
    <IsWebBootstrapper>false</IsWebBootstrapper>
    <CheckForOverflowUnderflow>true</CheckForOverflowUnderflow>
    <IncludeNativeLibrariesForSelfExtract>true</IncludeNativeLibrariesForSelfExtract>
    <DebuggerSupport>true</DebuggerSupport>
    <DebugType>embedded</DebugType>
    
    <PublishSingleFile>true</PublishSingleFile>

    </PropertyGroup>
    ...
    <ItemGroup>
        <PackageReference Include="System.Data.SQLite" Version="1.0.118">
            <ExcludeFromSingleFile>true</ExcludeFromSingleFile>
        </PackageReference>
    ...

1. 手动指定SQLite原生库路径 #

单文件打包时，原生库会被提取到临时目录，旧版System.Data.SQLite可能无法自动识别。在初始化连接前添加以下代码：

// 获取单文件应用的实际运行目录
var runtimeDir = Path.GetDirectoryName(System.Diagnostics.Process.GetCurrentProcess().MainModule.FileName);
// 强制指定SQLite原生库的查找目录
System.Data.SQLite.SQLiteConnection.SetConfig(System.Data.SQLite.SQLiteConfigOption.Directory, runtimeDir);

2. 升级System.Data.SQLite版本 #

你使用的1.0.118版本对.NET单文件发布的支持存在缺陷，升级到1.0.119及以上稳定版，新版本修复了大量单文件打包的兼容问题。

3. 优化csproj打包配置 #

在PropertyGroup中补充以下配置，确保原生库正确提取：

<PropertyGroup>
    <!-- 已有配置保留，新增以下项 -->
    <SelfContained>true</SelfContained>
    <PublishTrimmed>false</PublishTrimmed> <!-- 暂时关闭裁剪，避免SQLite组件被误删 -->
</PropertyGroup>

同时直接排除SQLite原生库并强制复制到发布目录：

<ItemGroup>
    <NativeLibrary Include="sqlite3.dll">
        <ExcludeFromSingleFile>true</ExcludeFromSingleFile>
        <CopyToPublishDirectory>Always</CopyToPublishDirectory>
    </NativeLibrary>
</ItemGroup>

4. 改用相对路径构建连接字符串 #

绝对路径在单文件发布后可能失效，改用相对路径结合运行目录生成连接字符串：

var dbFullPath = Path.Combine(AppContext.BaseDirectory, "db", "ManagerOrdini.db");
ProgramParameters.connectionStringAdmin = $"Data Source={dbFullPath};cache=shared;synchronous=NORMAL;journal_mode=WAL;temp_store=memory;mmap_size=30000000000;";

5. 确保数据库文件被正确发布 #

检查数据库文件ManagerOrdini.db的属性，设置复制到输出目录为「始终复制」，并在csproj中添加：

<ItemGroup>
    <None Include="db\ManagerOrdini.db">
        <CopyToPublishDirectory>PreserveNewest</CopyToPublishDirectory>
    </None>
</ItemGroup>

保证打包时数据库文件被复制到publish目录的db子文件夹中。

内容的提问来源于stack exchange，提问作者Razorphyn