我尝试了几乎所有的解决方案，但没有任何运气。最终解决这个问题的方法是将我选择的平台对应的SQLite.Interop.dll的副本直接放在我的安装项目的根目录下。

我不知道为什么它起作用了，但它确实起了作用。

超过30个答案，但我用了不同的方法。

我有两个独立的项目。一个Windows服务，和一个Windows窗体应用程序。应用程序引用WS项目，两者都引用SQLite核心nuget包。

在构建WS项目时，有x64和x32文件夹。但在构建应用程序时，文件夹不会显示出来。

检查这里的答案，我不能让他们工作。但是我发现WS项目中有以下代码片段，而App项目中没有。我添加了它，现在文件夹显示正确。

<Import Project="..\packages\System.Data.SQLite.Core.1.0.112.0\build\net46\System.Data.SQLite.Core.targets" Condition="Exists('..\packages\System.Data.SQLite.Core.1.0.112.0\build\net46\System.Data.SQLite.Core.targets')" />

I don't know why this has not been included yet, but I had to do the research and find this out for myself, so hopefully someone will find this answer and be saved the trouble. This was for a WPF app. It worked fine on my Dev box, but did not work on the computer where I was copying it and got the Unable to load DLL 'SQLite.Interop.dll' error. I ported over all of its associated directories and files, directly from my "Debug" folder to this other computer when I got the same error as the OP when I ran it. My "bin" folder that contained my DLLs had been copied to "Debug\bin" and all were included, along with my application files when I did my copying to the other computer using this path, so it was not missing any files.

我在其他答案中看到的不适用的东西:

I did not use the NuGet package or need to create x86 or x64 folders that it seems that NuGet package creates. My DLLs (System.Data.SQLite and SQLite.Interop.dll, along with System.Data.SQLite.config) are in the "bin" folder in my project and were copied in manually (create "bin" folder in Solution Explorer in VS, paste DLLs into this folder in Windows Explorer, use Add > Existing Item to bring files into VS folder/project). Then I reference them as Referenced Assemblies in my project using that location ("References" > "Add Reference", and browse to one, rinse, repeat for the rest). This ensures my project knows exactly where they are. I did not need to reference any SQLite DLL file in my app.config or even touch my MyProject.csproj file. I did not even need to specify a particular processor! My project's build is for "Any CPU", even though I have only mixed or 64-bit DLLs and will only be running on Windows 7+, which are 64-bit OSes. (no x86-only/32-bit solely DLLs) I was already specifying them as "Content" and "copy if newer" for these DLLs when I experienced the OP's error.

我从https://system.data.sqlite.org/index.html/doc/trunk/www/faq.wiki#q20上找到了这个:

(11) Why do I get a DllNotFoundException (for "sqlite3.dll" or "SQLite.Interop.dll") when trying to run my application? Either the named dynamic link library (DLL) cannot be located or it cannot be loaded due to missing dependencies. Make sure the named dynamic link library is located in the application directory or a directory along the system PATH and try again. Also, be sure the necessary Visual C++ runtime redistributable has been installed unless you are using a dynamic link library that was built statically linked to it.

我要强调这段内粗体的部分。目标计算机是新的，除了. net 4.0之外没有加载任何程序。一旦我安装了c++，它就能够完成SQLite的命令。这应该是第一个常见问题之一，也是先决条件的一部分，但它被埋在了第11位。我的开发计算机已经加载了它，因为它带有Visual Studio，所以这就是它在那里工作的原因。

下载: Visual c++ Redistributable for Visual Studio 2015 https://www.microsoft.com/en-us/download/details.aspx?id=48145

更新3(累积更新): https://www.microsoft.com/en-us/download/details.aspx?id=53587

我在这个问题上挣扎了很长一段时间，偶尔会发现测试设置不正确。请看这张图片:

我只要取消测试设置，问题就消失了。否则会出现异常。 希望这能帮助到一些人。 不确定这是根本原因。

还添加了dll到测试项目(通过Nuget管理器)，它修复了它。

我发现当我允许Nuget更新SQLite到1.0.115.5时，我的项目不再需要'SQLite. interop .dll'。