C#script

In some cases, you need to dynamically execute C#code during program execution. For example, you need to save certain algorithms that change frequently in a configuration file, and read and perform operations from the configuration file during execution. At this point, you can use C#scripts to do this.

使用 C#脚本需要引用库Microsoft.CodeAnalysis.CSharp.Scripting，下面是一些示例：

The most basic usage is to calculate arithmetic expressions:

Console.Write("测试基本算数表达式:(1+2)*3/4");
var res = await CSharpScript.EvaluateAsync("(1+2)*3/4");
Console.WriteLine(res);

如果需要使用比较复杂的函数，可以使用WithImports引入名称空间：

Console.WriteLine("测试Math函数:Sqrt(2)");
res = await CSharpScript.EvaluateAsync("Sqrt(2)", ScriptOptions.Default.WithImports("System.Math"));
Console.WriteLine(res);

不仅是计算函数，其他函数比如IO，也是可以的：

Console.WriteLine(@"测试输入输出函数:Directory.GetCurrentDirectory()");
res = await CSharpScript.EvaluateAsync("Directory.GetCurrentDirectory()",
     ScriptOptions.Default.WithImports("System.IO"));
Console.WriteLine(res);

String functions can be called directly:

Console.WriteLine(@"测试字符串函数:""Hello"".Length");
res = await CSharpScript.EvaluateAsync(@"""Hello"".Length");
Console.WriteLine(res);

如果需要传递变量，可以将类的实例作为上下文进行传递，下面的例子中使用了Student类：

Console.WriteLine(@"测试变量:");
var student = new Student { Height = 1.75M, Weight = 75 };
await CSharpScript.RunAsync("BMI=Weight/Height/Height", globals: student);
Console.WriteLine(student.BMI);

类Student:

public class Student
{
    public Decimal Height { get; set; }

    public Decimal Weight { get; set; }

    public Decimal BMI { get; set; }

    public string Status { get; set; } = string.Empty;
}

Reused scripts can be reused:

Console.WriteLine(@"测试脚本编译复用:");
var scriptBMI = CSharpScript.Create<Decimal>("Weight/Height/Height", globalsType: typeof(Student));
scriptBMI.Compile();

Console.WriteLine((await scriptBMI.RunAsync(new Student { Height = 1.72M, Weight = 65 })).ReturnValue);

Functions can also be defined in scripts:

Console.WriteLine(@"测试脚本中定义函数:");
string script1 = "decimal Bmi(decimal w,decimal h) { return w/h/h; } return Bmi(Weight,Height);";

var result = await CSharpScript.EvaluateAsync<decimal>(script1, globals: student);
Console.WriteLine(result);

Variables can also be defined in scripts:

Console.WriteLine(@"测试脚本中的变量:");
var script =  CSharpScript.Create("int x=1;");
script =  script.ContinueWith("int y=1;");
script =  script.ContinueWith("return x+y;");
Console.WriteLine((await script.RunAsync()).ReturnValue);

The complete example can be downloaded from github: github.com/zhenl/CSharpScriptDemo

This article comes from the Blog Park. Author: Looking for nameless qualities. Please indicate the original link to reprint it: www.cnblogs.com/zhenl/p/15714453.html