我用CMake创建了一个C++ DLL。C++项目由以下文件组成：

• src/setup.cpp
• src/setup.h
• CMakeLists.txt

setup.cpp如下：

#include "setup.h"

int myFunction() {
    return 42;
}

setup.h如下所示：

#ifndef SETUP_DLL
#define SETUP_DLL

int myFunction();

#endif

CMakeLists.txt如下所示：

cmake_minimum_required(VERSION 3.10)

# Define the project and supported versions
project(MyLibrary VERSION 1.0.0)

# Add options for compiling the library
set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED True)

# Add the library sources
add_library(MyLibrary SHARED src/setup.h src/setup.cpp)

# Specify the directory to search for headers
target_include_directories(MyLibrary PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/src)

# Specify the output name
set_target_properties(MyLibrary PROPERTIES OUTPUT_NAME "MyLibrary_${PROJECT_VERSION}")

# Specify the output path
set_target_properties(MyLibrary PROPERTIES LIBRARY_OUTPUT_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/lib")

我现在试图将这个DLL导入到C#项目中。为此，我在Visual Studio 2019中右键单击项目，选择“添加”，“引用”，“浏览”，然后选择我创建的DLL文件。但是，我收到错误消息Could not add reference to 'Path\to\file.dll'. Make sure the file is accessible and that the assembly or COM component is valid.
是什么原因导致了这个错误？如何在C#项目中成功添加对C++ DLL的引用？