怎样能执行"GetA()+GetB()",并返回数据？

Question

有两个方法public class MyTem
    {
        public MyTem() { }
        public static int GetA()
        {
            return 1;
        }        public static int GetB()
        {
            return 2;
        }
    }现在已知字符串："GetA()+GetB()"C#代码如何可以执行成：int i=GetA()+GetB()------------------------------------------------------------------
当然，不仅是以上定义，还要能解决同类问题，比如ABS(GetA()+5)-GetB()等等也看过CodeDOM,但理解不深，不过不知道能不能解决这个问题。
请各路高手多多援助！

Answer 1

 int i=MyTem.GetA()+MyTem.GetB(); 其他类似，但都要定义成静态的． public static int ABS() 
 
　

Answer 2

楼上，不是这个意思。是通过字符串“GetA()+GetB()”后，执行GetA()+GetB()，也就是说像C++的宏一样的东东。

Answer 3

CodeDOM可以解决这样的问题，只要你能写出一个这样的程序问题就解决了。

Answer 4

CodeMemberMethod GetMethod = new CodeMemberMethod();GetMethod.Comments.Add(new CodeCommentStatement("GetFunction"));
GetMethod.Name = "GetFunction";//方法名 
GetMethod.Attributes = MemberAttributes.Public;//可见性 
GetMethod.Parameters.Add(......);//参数
......==========================================================
hbxtlhx ,能帮写几行例子吗？

Answer 5

你只能
把整个“public class MyTem 
    { 
        public MyTem() { } 
        public static int GetA() 
        { 
            return 1; 
        }         public static int GetB() 
        { 
            return 2; 
        }
        
        public static int GetValue()
        {
            return GetA()+GetB();
        } 
    }”当成字符串，然后即时编译，调用GetValue方法得到返回值

Answer 6

那就提供一部分动态编译的代码吧，仅供参考，对楼主问题可能有用：
private List<string> m_using = new List<string>();
public frmMain()
{
InitializeComponent();
m_using.Add("System.dll");
} public static bool CompileCSharpCode(List<string> usings, string source, TextBox outputBox)
{
CSharpCodeProvider provider = new CSharpCodeProvider();
CompilerParameters cp = new CompilerParameters();
foreach (string us in usings)
{
cp.ReferencedAssemblies.Add(us);
}
cp.GenerateExecutable = false;
cp.OutputAssembly = null;
cp.GenerateInMemory = true; CompilerResults cr = provider.CompileAssemblyFromSource(cp, source);
if (cr.Errors.Count > 0)
{
outputBox.Text += string.Format("Errors building \r\n{0}", source);
outputBox.Text += "\r\n"; foreach (CompilerError ce in cr.Errors)
{
outputBox.Text += "(" + ce.ErrorNumber + ")" + ce.ErrorText;
outputBox.Text += "\r\n";
} }
else
{
outputBox.Text += "built successfully.\r\n";
} if (cr.Errors.Count > 0)
{
return false;
}
else
{
try
{
outputBox.Text += StartRun(cr.CompiledAssembly);
outputBox.Text += "\r\n";
}
catch (Exception ex)
{
outputBox.Text += ex.Message;
outputBox.Text += "\r\n";
}
return true;
}
} private static string StartRun(Assembly assembly)
{
Type[] types = assembly.GetTypes();
if (types != null && types.Length > 0)
{
Type type = types[0];
if (type != null)
{
object obj = assembly.CreateInstance(type.FullName);
MethodInfo mi = type.GetMethod("main", BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public);
if (mi != null)
{
object tmpRet = mi.Invoke(obj, null);
if (tmpRet != null)
{
return tmpRet.ToString();
}
}
}
}
return null;
} private void tbnRun_Click(object sender, EventArgs e)
{
this.txtOutput.Clear();
CompileCSharpCode(this.m_using, this.txtCode.Text, this.txtOutput);
}

Answer 7

参考一下http://www.chenjiliang.com/Article/View.aspx?ArticleID=2767&TypeID=84

Answer 8

CodeDOM 速度很慢, 建议自行解释字符串取得方法列表后利用反射调用...

Answer 9

lovefootball： 参考的方法不可取，GetA()和GetB()等等这些方法都是C#类里的，都是运行在后台的。shinaterry : 我有这种担心，而且也不知道在多用户的情况下，编译和生成是否有问题。

Answer 10

hbxtlhx ，请教：using System;
using System.Collections.Generic;
using System.Text;
using System.CodeDom;
using System.CodeDom.Compiler;
using Microsoft.CSharp;
using System.Reflection;namespace WindowsApplication1
{
    public class Eval
    {
        public static object GetValue( string value )
        {
            string codeSnippet = "using System; " + "\r\n" +
                                            "namespace CzG {" + "\r\n" +
                                                        " public class Eval" + "\r\n" +
                                                        " {" + "\r\n" +
                                            "       public Eval(){} " + "\r\n" +
                                                        "  public object GetValue()" + "\r\n" +
                                                        "  {" + "\r\n" +
                                                        "   return " + value + ";" + "\r\n" +
                                                        "  }" + "\r\n" +
                                                        " } }";            CodeSnippetCompileUnit unit = new CodeSnippetCompileUnit( codeSnippet ); 
         
           ICodeCompiler compiler =  new CSharpCodeProvider().CreateCompiler();
           CompilerParameters para = new CompilerParameters();
           para.ReferencedAssemblies.Add( "System.dll" );
           para.GenerateInMemory = true;
           para.GenerateExecutable = false;
           para.OutputAssembly = "Eval.dll";
           
           Assembly asm = compiler.CompileAssemblyFromDom( para , unit ).CompiledAssembly;           Type type = asm.GetType("CzG.Eval");
           MethodInfo mi = type.GetMethod( "GetValue" , BindingFlags.Public | BindingFlags.Instance );           object obj = asm.CreateInstance("CzG.Eval");
           return mi.Invoke( obj , null );
          }        public static string GetA() { return "A"; }
        public static string GetB() { return "B"; }
    }
}private void button2_Click(object sender, EventArgs e)
        {
            string s1 = Convert.ToString(Eval.GetValue("(5 + 6*3)-10"));
            //string s2 = Convert.ToString(Eval.GetValue("WindowsApplication1.GetA()"));
}========================================================
以上代码可得到s1，但想得到s2是提示编译错误，如何解决？

Answer 11

修改如下:using System;
using System.Collections.Generic;
using System.Text;
using System.CodeDom;
using System.CodeDom.Compiler;
using Microsoft.CSharp;
using System.Reflection;namespace WindowsApplication1
{
    public class Demo
    {
        public static object GetValue(string value)
        {
            string codeSnippet = "using System;" + "\r\n" +
                                 "using " + typeof(Demo).Namespace + ";" + "\r\n" +
                                            "namespace CzG {" + "\r\n" +
                                                        " public class Eval" + "\r\n" +
                                                        " {" + "\r\n" +
                                            "       public Eval(){} " + "\r\n" +
                                                        "  public object GetValue()" + "\r\n" +
                                                        "  {" + "\r\n" +
                                                        "   return " + value + ";" + "\r\n" +
                                                        "  }" + "\r\n" +
                                                        " } }";            CodeSnippetCompileUnit unit = new CodeSnippetCompileUnit(codeSnippet);            ICodeCompiler compiler = new CSharpCodeProvider().CreateCompiler();
            String[] referenceAssemblies = { typeof(Demo).Module.FullyQualifiedName, "System.dll" };
            CompilerParameters para = new CompilerParameters(referenceAssemblies);
            para.GenerateInMemory = true;
            para.GenerateExecutable = false;
            para.OutputAssembly = "Eval.dll";            Assembly asm = compiler.CompileAssemblyFromDom(para, unit).CompiledAssembly;            Type type = asm.GetType("CzG.Eval");
            MethodInfo mi = type.GetMethod("GetValue", BindingFlags.Public | BindingFlags.Instance);            object obj = asm.CreateInstance("CzG.Eval");
            return mi.Invoke(obj, null);
        }        public static string GetA() { return "A"; }
        public static string GetB() { return "B"; }
    }
}测试代码:private void button2_Click(object sender, EventArgs e)
{
    string s1 = Convert.ToString(Eval.GetValue("(5 + 6*3)-10"));
    string s2 = Convert.ToString(Eval.GetValue("WindowsApplication1.Demo.GetA()"));
}

Answer 12

ref: 编译和生成是否有问题。
---------
^ō^ 那就视乎你的服务器的承受能力...

Answer 13

简单求值运算我一般都用Script对象直接Eval得出

Answer 14

Eval.Cs单元
using System;
using System.Collections.Generic;
using System.Text;
using System.CodeDom;
using System.CodeDom.Compiler;
using Microsoft.CSharp;
using System.Reflection;namespace WindowsApplication1
{
    public class Demo
    {
        public static object GetValue(string value)
        {
            string codeSnippet = "using System;" + "\r\n" +
                                 "using " + typeof(Demo).Namespace + ";" + "\r\n" +
                                            "namespace CzG {" + "\r\n" +
                                                        " public class Eval" + "\r\n" +
                                                        " {" + "\r\n" +
                                            "       public Eval(){} " + "\r\n" +
                                                        "  public object GetValue()" + "\r\n" +
                                                        "  {" + "\r\n" +
                                                        "   return " + value + ";" + "\r\n" +
                                                        "  }" + "\r\n" +
                                                        " } }";            CodeSnippetCompileUnit unit = new CodeSnippetCompileUnit(codeSnippet);            ICodeCompiler compiler = new CSharpCodeProvider().CreateCompiler();
            String[] referenceAssemblies = { typeof(Demo).Module.FullyQualifiedName, "System.dll" };
            CompilerParameters para = new CompilerParameters(referenceAssemblies);
            para.GenerateInMemory = true;
            para.GenerateExecutable = false;
            para.OutputAssembly = "Eval.dll";            Assembly asm = compiler.CompileAssemblyFromDom(para, unit).CompiledAssembly;            Type type = asm.GetType("CzG.Eval");
            MethodInfo mi = type.GetMethod("GetValue", BindingFlags.Public | BindingFlags.Instance);            object obj = asm.CreateInstance("CzG.Eval");
            return mi.Invoke(obj, null);
        }        public static string GetA() { return "A"; }
        public static string GetB() { return "B"; }
    }}
调用测试代码：
private void button2_Click(object sender, EventArgs e)
        {
            string s = Convert.ToString(Demo.GetValue("WindowsApplication1.Demo.GetA()+WindowsApplication1.Demo.GetB()"));
            txtOutput.Text = s;
        }================================
shinaterry 的代码是可以的。