Roslyn（二）动态编译DLL和缺少Private.CoreLib的问题

古城微笑少年丶 2023-10-14 16:10 21阅读 0赞

### CoreLib问题 ###

最近学习Roslyn，看如何编译一个Dll来使用，网上有很多Roslyn的文章，但是都有点问题，我编译的DLL加入到别的项目使用，就会提示：

严重性	代码	说明	项目	文件	行	禁止显示状态
    错误	CS0012	类型“Object”在未引用的程序集中定义。必须添加对程序集“System.Private.CoreLib, Version=7.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e”的引用。	ConsoleApp1	G:\Github\MMCServer\MMCEngine\ConsoleApp1\Program.cs	14	活动

#### 先放上代码来： ####

##### 动态脚本： #####

using System;
        public class MyLib
        {
        
            public static string GetGreeting()
            {
        
                return "Ahoy";
            }
        }

##### 生成脚本： #####

public void writedll()
            {
        
                string sourceCode = File.ReadAllText(@"c:\Temp\MyLib.cs");
                SyntaxTree syntaxTree = SyntaxFactory.ParseSyntaxTree(SourceText.From(sourceCode));
    
                var assemblyPath = Path.GetDirectoryName(typeof(object).Assembly.Location);
                Console.Write("dll path :"+ assemblyPath);
              
                List<MetadataReference> list = new List<MetadataReference>()
                {
        
                    MetadataReference.CreateFromFile(typeof(object).Assembly.Location),
                    MetadataReference.CreateFromFile(typeof(SyntaxTree).Assembly.Location),
                    MetadataReference.CreateFromFile(typeof(CSharpSyntaxTree).Assembly.Location)
                };
    
    
                CSharpCompilation compilation = CSharpCompilation
                    .Create("MyLib")
                    .WithOptions(new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary))
                    .AddReferences(list)
                    .AddSyntaxTrees(syntaxTree);
    
                EmitResult result = compilation.Emit(@"c:\Temp\MyLib.dll");
                if (!result.Success)
                    Console.Out.WriteLine(string.Join(Environment.NewLine, result.Diagnostics.Select(diagnostic => diagnostic.ToString())));
            }

我们运行这个函数后就生成了DLL。

##### 在控制台里运行 #####

然后我们创建一个控制台项目来使用这个MyLib.dll  
![在这里插入图片描述][901eb33c2b5c432a93fe902ba148af74.png]  
代码只有短短的两行

Console.WriteLine("Hello, World!");
    Console.WriteLine(MyLib.GetGreeting());

如下图，已经报告出了错误。

错误 CS0012 类型“Object”在未引用的程序集中定义。必须添加对程序集“System.Private.CoreLib, Version=7.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e”的引用。

![在这里插入图片描述][316055c821554e2087b6cd40b27c2154.png]  
在网络找了很多资料一直，大概是DLL编译引用了错误的元数据引用(MetadataReference)，应该引用“引用程序集（reference assemblies）”不应该引用“实现程序集（implementation assemblies）”。

那我们只改掉代码，路径里是我的，不同机器和版本可能位置不同，自行修改。

### 修改后 ###

public void writedll()
            {
        
                string sourceCode = File.ReadAllText(@"c:\Temp\MyLib.cs");
                SyntaxTree syntaxTree = SyntaxFactory.ParseSyntaxTree(SourceText.From(sourceCode));
    
                var assemblyPath = Path.GetDirectoryName(typeof(object).Assembly.Location);
                Console.Write("dll path :"+ assemblyPath);
                List<MetadataReference> list = new List<MetadataReference>()
                {
        
                    //MetadataReference.CreateFromFile(typeof(object).Assembly.Location),
                    //MetadataReference.CreateFromFile(typeof(SyntaxTree).Assembly.Location),
                    //MetadataReference.CreateFromFile(typeof(CSharpSyntaxTree).Assembly.Location)
                };
    
                string dllpath = @"C:\Program Files\dotnet\packs\Microsoft.NETCore.App.Ref\7.0.9\ref\net7.0\";
                foreach (string dll in Directory.GetFiles(dllpath, "*.dll"))
                {
        
                    if (!dll.Contains("VisualBasic"))
                        list.Add(MetadataReference.CreateFromFile(dll));
                }
                
                CSharpCompilation compilation = CSharpCompilation
                    .Create("MyLib")
                    .WithOptions(new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary))
                    .AddReferences(list)
                    .AddSyntaxTrees(syntaxTree);
    
                EmitResult result = compilation.Emit(@"c:\Temp\MyLib.dll");
                if (!result.Success)
                    Console.Out.WriteLine(string.Join(Environment.NewLine, result.Diagnostics.Select(diagnostic => diagnostic.ToString())));
            }

运行后，重新生成了DLL，这样就可以直接运行没有报错了。  
![在这里插入图片描述][db720d5196164656b2f7ef0d23e6bd7f.png]

### 最后 ###

当然这里的引用程序集比较粗暴，这里不再探讨。  
这个问题让我卡了很久，遇到同样的问题的可以参考借鉴吧。  
因为学习中，可能存在错误，还请留言。

\#参考  
[https://github.com/dotnet/core/issues/2082][https_github.com_dotnet_core_issues_2082]

[https://stackoverflow.com/questions/69042106/could-not-load-file-or-assembly-sharedlib-dll-when-dll-is-compiled-by-roslyn][https_stackoverflow.com_questions_69042106_could-not-load-file-or-assembly-sharedlib-dll-when-dll-is-compiled-by-roslyn]

[https://stackoverflow.com/questions/53514059/net-core-roslyn-cannot-find-system-decimal-in-assemblies][https_stackoverflow.com_questions_53514059_net-core-roslyn-cannot-find-system-decimal-in-assemblies]

[https://stackoverflow.com/questions/68109143/choose-references-dynamically-in-net-core-for-roslyn][https_stackoverflow.com_questions_68109143_choose-references-dynamically-in-net-core-for-roslyn]

[901eb33c2b5c432a93fe902ba148af74.png]: https://img-blog.csdnimg.cn/901eb33c2b5c432a93fe902ba148af74.png
[316055c821554e2087b6cd40b27c2154.png]: https://img-blog.csdnimg.cn/316055c821554e2087b6cd40b27c2154.png
[db720d5196164656b2f7ef0d23e6bd7f.png]: https://img-blog.csdnimg.cn/db720d5196164656b2f7ef0d23e6bd7f.png
[https_github.com_dotnet_core_issues_2082]: https://github.com/dotnet/core/issues/2082
[https_stackoverflow.com_questions_69042106_could-not-load-file-or-assembly-sharedlib-dll-when-dll-is-compiled-by-roslyn]: https://stackoverflow.com/questions/69042106/could-not-load-file-or-assembly-sharedlib-dll-when-dll-is-compiled-by-roslyn
[https_stackoverflow.com_questions_53514059_net-core-roslyn-cannot-find-system-decimal-in-assemblies]: https://stackoverflow.com/questions/53514059/net-core-roslyn-cannot-find-system-decimal-in-assemblies
[https_stackoverflow.com_questions_68109143_choose-references-dynamically-in-net-core-for-roslyn]: https://stackoverflow.com/questions/68109143/choose-references-dynamically-in-net-core-for-roslyn