如何在 C# 中从 CodeDom return 自定义 class?

How to return a custom class from CodeDom in C#?

我想从 Codedom 创建的函数中 return 自定义 class(例如 User)。我的 Userclass 在另一个 class 库中,与我的 Windows Application 在同一个解决方案中,我用它来生成动态代码。

CompilerResult returns 这些错误:

The type or namespace name 'TestApp' could not be found (are you missing a using directive or an assembly reference?)

The type or namespace name 'User' could not be found (are you missing a using directive or an assembly reference?)

这是我的代码:

StringBuilder sbCode = new StringBuilder();

sbCode.Append(@"using System.Windows.Forms;");
sbCode.Append(@"using Nikola.BusinessIntelligence.Objects;");
sbCode.Append(@"using System.Collections.Generic;");
sbCode.Append(@"using System.Text;");
sbCode.Append(@"using Microsoft.CSharp;");
sbCode.Append(@"using TestApp.Data;"); // User class is in this Class Lib

sbCode.Append(" public class Test {");
sbCode.Append(tbCode.Text);
sbCode.Append("}");

var cp = new CompilerParameters()
{
    GenerateInMemory = true,
    GenerateExecutable = false,
    ReferencedAssemblies =
    {
        "System.dll",
        "System.Core.dll",
        "System.Windows.dll",
        "System.Windows.Forms.dll",
    },
};

using (CSharpCodeProvider codeProvider = new CSharpCodeProvider())
{
    CompilerResults res = codeProvider.CompileAssemblyFromSource(cp, sbCode.ToString());
    var type = res.CompiledAssembly.GetType("Test");
    var obj = Activator.CreateInstance(type);
    var output = type.GetMethod("Execute").Invoke(obj, new object[] { });
}

这是我在 tbCode 文本框中编写的示例代码:

public User  Execute()
        {
            User usr = new User();
            return usr;
        }

两个问题:

  1. 你忘了namespace:

    sbCode.Append(" namespace SomeNameSpace{public class Test {");
    sbCode.Append(tbCode.Text);
    sbCode.Append("}}");
    
  2. 您正在尝试的代码中缺少 =

    User usr = new User();
    

关于编译器错误,您必须添加缺少的程序集。尝试像这样添加当前程序集使用的所有内容:

var options = new CompilerParameters();
// add all loaded assemblies
options.ReferencedAssemblies.AddRange(
    AppDomain.CurrentDomain.GetAssemblies().Where(item => !item.IsDynamic).Select(item => item.Location).ToArray());
options.GenerateExecutable = false;
options.GenerateInMemory = true;

// compile like this
var result = provider.CompileAssemblyFromSource(options, source);
if (result.Errors.HasErrors)
{
    // deal with errors
}

显然,如果您在代码中键入 using something;,则必须在 CompilerParameters 中使用的引用程序集列表中添加 something 相关的引用程序集:

var cp = new CompilerParameters()
        {
            GenerateInMemory = true,
            GenerateExecutable = false,
            ReferencedAssemblies =
            {
                "System.dll",
                "System.Core.dll",
                "System.Windows.dll",
                "System.Windows.Forms.dll",
                // I assume the following name of the assembly
                // however you should update it to the relevant name if needed
                "TestApp.Data.dll"
                },

        };