C++游戏引擎嵌入C#脚本调用Console.WriteLine遇System.DllNotFoundException

问题背景 #

我正在尝试将C#脚本嵌入到C++游戏引擎项目中，参考了Mono相关示例。目前代码能正常运行，也能访问C#类的方法，但调用Console.WriteLine()时会抛出异常，无法使用System相关函数。

相关代码 #

Dog.cs #

public class Dog
{
    static public void Type()
    {
        Console.WriteLine("a Dog!");
    }

    // 其他代码...
}

错误日志 #

Running the static method: Dog:Type()

Unhandled Exception:
System.TypeInitializationException: The type initializer for 'System.Console' threw an exception. ---> System.TypeInitializationException: The type initializer for 'System.ConsoleDriver' threw an exception. ---> System.TypeInitializationException: The type initializer for 'Sys' threw an exception. ---> System.DllNotFoundException: System.Native assembly:<unknown assembly> type:<unknown type> member:(null)
  at (wrapper managed-to-native) Interop+Sys.LChflagsCanSetHiddenFlag()
  at Interop+Sys..cctor () [0x00000] in <de882a77e7c14f8ba5d298093dde82b2>:0 
   --- End of inner exception stack trace ---
  at System.IO.FileSystem.FileExists (System.ReadOnlySpan`1[T] fullPath, System.Int32 fileType, Interop+ErrorInfo& errorInfo) [0x00007] in <de882a77e7c14f8ba5d298093dde82b2>:0 
  at System.IO.FileSystem.DirectoryExists (System.ReadOnlySpan`1[T] fullPath, Interop+ErrorInfo& errorInfo) [0x00000] in <de882a77e7c14f8ba5d298093dde82b2>:0 
  at System.IO.FileSystem.DirectoryExists (System.ReadOnlySpan`1[T] fullPath) [0x00000] in <de882a77e7c14f8ba5d298093dde82b2>:0 
  at System.IO.Directory.Exists (System.String path) [0x0001e] in <de882a77e7c14f8ba5d298093dde82b2>:0 
  at System.TermInfoDriver.SearchTerminfo (System.String term) [0x00044] in <de882a77e7c14f8ba5d298093dde82b2>:0 
  at System.TermInfoDriver..ctor (System.String term) [0x0004b] in <de882a77e7c14f8ba5d298093dde82b2>:0 
  at System.ConsoleDriver.CreateTermInfoDriver (System.String term) [0x00000] in <de882a77e7c14f8ba5d298093dde82b2>:0 
  at System.ConsoleDriver..cctor () [0x0004d] in <de882a77e7c14f8ba5d298093dde82b2>:0 
   --- End of inner exception stack trace ---
  at System.Console.SetupStreams (System.Text.Encoding inputEncoding, System.Text.Encoding outputEncoding) [0x00007] in <de882a77e7c14f8ba5d298093dde82b2>:0 
  at System.Console..cctor () [0x0007d] in <de882a77e7c14f8ba5d298093dde82b2>:0 
   --- End of inner exception stack trace ---
  at Dog.Type () [0x00000] in <f155b242589444d6a2f6baf230b1c326>:0 
[ERROR] FATAL UNHANDLED EXCEPTION: System.TypeInitializationException: The type initializer for 'System.Console' threw an exception. ---> System.TypeInitializationException: The type initializer for 'System.ConsoleDriver' threw an exception. ---> System.TypeInitializationException: The type initializer for 'Sys' threw an exception. ---> System.DllNotFoundException: System.Native assembly:<unknown assembly> type:<unknown type> member:(null)
  at (wrapper managed-to-native) Interop+Sys.LChflagsCanSetHiddenFlag()
  at Interop+Sys..cctor () [0x00000] in <de882a77e7c14f8ba5d298093dde82b2>:0 
   --- End of inner exception stack trace ---
  at System.IO.FileSystem.FileExists (System.ReadOnlySpan`1[T] fullPath, System.Int32 fileType, Interop+ErrorInfo& errorInfo) [0x00007] in <de882a77e7c14f8ba5d298093dde82b2>:0 
  at System.IO.FileSystem.DirectoryExists (System.ReadOnlySpan`1[T] fullPath, Interop+ErrorInfo& errorInfo) [0x00000] in <de882a77e7c14f8ba5d298093dde82b2>:0 
  at System.IO.FileSystem.DirectoryExists (System.ReadOnlySpan`1[T] fullPath) [0x00000] in <de882a77e7c14f8ba5d298093dde82b2>:0 
  at System.IO.Directory.Exists (System.String path) [0x0001e] in <de882a77e7c14f8ba5d298093dde82b2>:0 
  at System.TermInfoDriver.SearchTerminfo (System.String term) [0x00044] in <de882a77e7c14f8ba5d298093dde82b2>:0 
  at System.TermInfoDriver..ctor (System.String term) [0x0004b] in <de882a77e7c14f8ba5d298093dde82b2>:0 
  at System.ConsoleDriver.CreateTermInfoDriver (System.String term) [0x00000] in <de882a77e7c14f8ba5d298093dde82b2>:0 
  at System.ConsoleDriver..cctor () [0x0004d] in <de882a77e7c14f8ba5d298093dde82b2>:0 
   --- End of inner exception stack trace ---
  at System.Console.SetupStreams (System.Text.Encoding inputEncoding, System.Text.Encoding outputEncoding) [0x00007] in <de882a77e7c14f8ba5d298093dde82b2>:0 
  at System.Console..cctor () [0x0007d] in <de882a77e7c14f8ba5d298093dde82b2>:0 
   --- End of inner exception stack trace ---
  at Dog.Type () [0x00000] in <f155b242589444d6a2f6baf230b1c326>:0

已尝试操作 #

1. 调用mono_set_dirs("/usr/lib/", "/etc/")设置Mono的DLL查找路径，/usr/lib/mono/4.5/下确实存在对应DLL。
2. 将/usr/lib/mono/4.5/下的System.dll复制到项目目录并手动调用mono_domain_assembly_open(domain, "System.dll")加载，但问题未解决。

环境信息 #

• 系统：Ubuntu 22.04 LTS
• 已本地安装Mono，并通过.so文件链接到项目中

解决方案 #

原因分析

错误中的System.DllNotFoundException并非找不到托管的System.dll，而是找不到原生的System.Native.so库——这是Mono实现System类库底层功能的原生依赖，Console.WriteLine()的终端交互逻辑依赖这个库。

修复步骤

1. 确认原生库路径
   在Ubuntu 22.04中，System.Native.so通常位于/usr/lib/mono-native/或/usr/lib/x86_64-linux-gnu/目录下。可以用命令定位：

   find /usr -name "System.Native.so"
   

2. 确保程序能加载到该库

   • 方法一：将找到的System.Native.so复制到项目可执行文件所在目录，或者添加其所在路径到LD_LIBRARY_PATH环境变量：

     export LD_LIBRARY_PATH="/usr/lib/mono-native/:$LD_LIBRARY_PATH"
     

     然后运行游戏引擎程序。
   • 方法二：在编译C++项目时，通过链接器参数指定该库的路径，例如：

     -L/usr/lib/mono-native/ -lSystem.Native
     

3. 替代方案：自定义控制台输出
   如果不想依赖原生库，可以在C#中实现自定义的输出方法，通过Mono的互操作回调到C++的日志系统：

   • C#端：

     public static class Logger
     {
         [System.Runtime.InteropServices.DllImport("YourGameEngine")]
         private static extern void LogMessage(string msg);
     
         public static void WriteLine(string msg)
         {
             LogMessage(msg);
         }
     }
     

   • C++端实现LogMessage函数：

     extern "C" void LogMessage(const char* msg)
     {
         // 调用引擎的日志输出逻辑，比如printf或自定义日志系统
         printf("%s\n", msg);
     }
     

   之后在C#代码中使用Logger.WriteLine()替代Console.WriteLine()。

内容的提问来源于stack exchange，提问作者Pierre Mauger