如果您试图在64位项目中运行32位dll，也可能会出现此错误。

当我在x86和x64文件夹中放置相同的文件(32位版本的SQLite.Interop.dll)时，我得到了这个。

大会上会有竞争吗?检查DLL上是否有其他具有文件锁的应用程序。

如果是这个原因，使用Sysinternal的Process Explorer之类的工具来发现有问题的程序应该很容易。

HTH, 粘土

来自NuGet的多体系结构(x86, x64)版本SQLite的默认安装显示了您所描述的行为。如果你想加载。net运行时选择在你的机器上运行你的应用程序的实际体系结构的正确版本，那么你可以给DLL加载器一个关于在哪里找到正确库的提示，如下所示:

在Program.Main()之前添加kernel32.dll函数调用SetDLLDirectory()的声明:

    [System.Runtime.InteropServices.DllImport("kernel32.dll", CharSet = System.Runtime.InteropServices.CharSet.Unicode, SetLastError = true)]
    [return: System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.Bool)]
    static extern bool SetDllDirectory(string lpPathName);

然后使用您自己的方法确定正确的子目录，以找到'SQLite.Interop.dll'的特定于体系结构的版本。我使用以下代码:

    [STAThread]
    static void Main()
    {
        int wsize = IntPtr.Size;
        string libdir = (wsize == 4)?"x86":"x64";
        string appPath = System.IO.Path.GetDirectoryName(Application.ExecutablePath);
        SetDllDirectory(System.IO.Path.Combine(appPath, libdir));

所以，我的问题是SQLite试图在WPF的设计时加载。由于我只关心x86环境，所以我将CPU首选项设置为x86环境，并将Nuget包中的SQLite.Interop.dll复制到解决方案的根目录。重新启动解决方案，所有问题都消失了。因此，如果遇到设计时问题，请将库放到解决方案的根目录中。

此外，我在运行时遇到了类似的问题，所以我必须将SQLite.Interop.dll的副本放入我的项目中，并将其设置为复制，如果它在属性中较新的。似乎x86和x64提供的文件夹是完全无用的。还需要进一步的调查，但总的来说…在你的项目中手动引用SQLite比使用Nuget包更容易。

此外，官方常见问题解答如下:

(20) When the System.Data.SQLite project is compiled and run from inside Visual Studio, why do I get a DllNotFoundException or a BadImageFormatException (for "sqlite3.dll" or "SQLite.Interop.dll") when trying to run or debug the application? When compiling and running a solution from within Visual Studio that uses the System.Data.SQLite project (including the test project), it is very important to select the correct build configuration and platform. First, managed applications to be debugged inside Visual Studio cannot use the mixed-mode assembly (i.e. because it is always compiled to the platform-specific build output directory). This is necessary to properly support building binaries for multiple platforms using the same source project files. Therefore, only the "DebugNativeOnly" or "ReleaseNativeOnly" build configurations should be selected when running a managed application from inside Visual Studio that relies upon the System.Data.SQLite assembly. These build configurations contain a custom post-build step that copies the required native assembly to the managed output directory (i.e. to enable running the managed binaries in-place). However, this post-build step will only be performed if the selected platform matches that of the operating system (e.g. "Win32" for 32-bit Windows and "x64" for 64-bit Windows). Therefore, it is good practice to double-check the selected build platform against the operating system prior to attempting to run a managed project in the solution.

https://system.data.sqlite.org/index.html/doc/trunk/www/faq.wiki#q20

升级到Visual Studio 2019版。16.10导致了我的问题，其中msbuild报告了以下System.Data.SQLite.Core-package:

CopySQLiteInteropFiles:
Skipping target "CopySQLiteInteropFiles" because it has no outputs.

https://github.com/dotnet/msbuild/issues/6493

微软表示，该漏洞已被修复。16.10.4. 现在只需要等待AppVeyor更新他们的Visual Studio图像(在此之前，可以使用以前的Visual Studio 2019)。

现在，AppVeyor正在为当前和以前的Visual Studio 2019-image使用破碎的dotnet-build-engine。现在一个必须显式安装dotnet sdk ver。5.0.302:

Invoke-WebRequest -Uri 'https://dot.net/v1/dotnet-install.ps1' -UseBasicParsing -OutFile "$env:temp/dotnet-install.ps1"; & $env:temp\dotnet-install.ps1 -Architecture x64 -Version 5.0.302 -InstallDir "$env:ProgramFiles\dotnet"

I got the same problem. However, finally, I can fix it. Currently, I use Visual Studio 2013 Community Edition. I just use Add->Existing Item... and browse to where the SQLite.Data.SQLite files are in (my case is 'C:\Program Files (x86)\System.Data.SQLite\2013\bin'). Please don't forget to change type of what you will include to Assembly Files (*.dll; *.pdb). Choose 'SQLite.Interop.dll' in that folder. From there and then, I can continue without any problems at all. Good luck to you all. ^_^ P.S. I create web form application. I haven't tried in window form application or others yet.