C#：从字符串和引用局部变量执行代码

Question

我正在开发 C# 应用程序，我希望能够从字符串中执行代码，其中该字符串在字符串外部的范围内包含一个变量。例如：

using Microsoft.CodeAnalysis.CSharp.Scripting;

///...


List<int> myNumbers = new List<int>();
//do something here to populate myNumbers

//userProvidedExpression will be a string that contains curNumber and represents a statement that would evaluate to a bool
string userProvidedExpression = "curNumber == 4"; 

foreach(int curNumber in myNumbers)
{
    if(   await CSharpScript.EvaluateAsync<bool>(userProvidedExpression) )
    {
        Console.WriteLine("curNumber MATCHES user-provided condition");
    }
    else
    {
        Console.WriteLine("curNumber DOES NOT MATCH user-provided condition");
    }
}

显然，我遇到的主要困难是从 userProvidedExpression 中获取 "curNumber"，使其被识别为来自 foreach 循环的相同 curNumber。有什么简单的方法可以做到这一点？

Answer 1

As the documentation says，你需要添加一个全局变量，像这样：

public class Globals
{
    public int curNumber;
}

async static void Main(string[] args)
{
    List<int> myNumbers = new List<int>();
    myNumbers.Add(4);

    //userProvidedExpression will be a string that contains curNumber and represents a statement that would evaluate to a bool
    string userProvidedExpression = "curNumber == 4";

    foreach (int curNumber in myNumbers)
    {
        var globals = new Globals
        {
            curNumber = curNumber
        };
        if (await CSharpScript.EvaluateAsync<bool>(userProvidedExpression, globals: globals))
        {
            Console.WriteLine("curNumber MATCHES user-provided condition");
        }
        else
        {
            Console.WriteLine("curNumber DOES NOT MATCH user-provided condition");
        }
    }

    Console.ReadLine();
}

C#：从字符串和引用局部变量执行代码

C#: Execute Code from String and Reference Local Variable

c#

roslyn