一个关于动态编译时 Evidence的问题

  1 using System.Reflection;
  2 using System.CodeDom;
  3 using System.CodeDom.Compiler;
  4 using System.Collections;
  5 using System.Security;
  6 using System.Security.Policy;
  7 using System.Security.Permissions;
  8 using Microsoft.CSharp;
  9 using Microsoft.VisualBasic;
 10 using System.IO;
 11 using System.Windows.Forms;
 12 
 13 using Bee.Core.Util;
 14 using Bee.Core.Log;
 15 
 16 namespace Bee.Core.Script
 17 {
 18     /// <summary>
 19     /// DotNetScriptEngine 的摘要说明。
 20     /// </summary>
 21     public class DotNetScriptEngine
 22     {
 23         public DotNetScriptEngine()
 24         {
 25             //
 26             // TODO: 在此处添加构造函数逻辑
 27             //
 28         }
 29         /// <summary>
 30         /// This method is used internally.
 31         /// </summary>
 32         public virtual Assembly Compile(ArrayList references, string language, string source,string url)
 33         {
 34             Assembly generatedAssembly=null;
 35             // get a compiler for the appropriate language.
 36             CodeDomProvider codeProvider=GetCompiler(language);
 37             if(codeProvider == null)
 38             {
 39                 return null;
 40             }
 41             // setup the compiler defaults.  Maybe make this application definable at some point.
 42             ICodeCompiler compiler=codeProvider.CreateCompiler();
 43             CompilerParameters compilerParams=new CompilerParameters();
 44             
 45             compilerParams.CompilerOptions = "/target:library /optimize";
 46             compilerParams.GenerateExecutable=false;
 47             compilerParams.GenerateInMemory=true;
 48             compilerParams.IncludeDebugInformation=false;
 49             compilerParams.ReferencedAssemblies.Add("mscorlib.dll");
 50             compilerParams.ReferencedAssemblies.Add("System.dll");
 51 
 52             compilerParams.Evidence=GetEvidence(url);
 53             
 54             
 55             try
 56             {
 57                 // compile the source code
 58                 CompilerResults results=compiler.CompileAssemblyFromSource(compilerParams, source);
 59                 if (results.Errors.Count > 0)
 60                 {
 61                     foreach(CompilerError error in results.Errors)
 62                     {
 63                         OnLogCompileErr(error);
 64                     }
 65                     return null;
 66                 }
 67                 else
 68                 {
 69                     // get the resultant assembly.
 70                     generatedAssembly=results.CompiledAssembly;
 71                 }
 72             }
 73             catch(Exception ex)
 74             {
 75                 return null;
 76             }
 77             return generatedAssembly;
 78         }
 79 
 80         /// <summary>
 81         /// This method is used internally.
 82         /// </summary>
 83         protected virtual CodeDomProvider GetCompiler(string language)
 84         {
 85             CodeDomProvider cdp=null;
 86             if ( (language=="C#") || (language.ToUpper()=="CS") )
 87             {
 88                 cdp=new CSharpCodeProvider();
 89             }
 90             else if (language.ToUpper()=="VB")
 91             {
 92                 cdp=new VBCodeProvider();
 93             }
 94             return cdp;
 95         }
 96 
 97         protected virtual Evidence GetEvidence(string url)
 98         {
 99             try
100             {
101                 Evidence evidence=new Evidence();
102                 //NamedPermissionSet nps = new NamedPermissionSet(
103                 //evidence.AddHost(Zone.CreateFromUrl(url));
104                 //evidence.AddHost(Site.CreateFromUrl(url));
105                 evidence.AddHost(new Url(url));
106                 return evidence;
107             }
108             catch(Exception)
109             {
110                 return null;
111             }
112         }
113     }
114 }

用上面这个类来编译一段C＃的代码，运行时抛出一个异常PolicyException,message是HRESULT 中的异常：0x80131418。
stacktracestring是：
"   at System.Reflection.Assembly.nLoadImage(Byte[] rawAssembly, Byte[] rawSymbolStore, Evidence evidence, StackCrawlMark& stackMark)\r\n   at System.Reflection.Assembly.Load(Byte[] rawAssembly, Byte[] rawSymbolStore, Evidence securityEvidence)\r\n   at System.CodeDom.Compiler.CodeCompiler.FromFileBatch(CompilerParameters options, String[] fileNames)\r\n   at System.CodeDom.Compiler.CodeCompiler.FromSourceBatch(CompilerParameters options, String[] sources)\r\n   at System.CodeDom.Compiler.CodeCompiler.FromSource(CompilerParameters options, String source)\r\n   at System.CodeDom.Compiler.CodeCompiler.System.CodeDom.Compiler.ICodeCompiler.CompileAssemblyFromSource(CompilerParameters options, String source)\r\n   at Bee.Core.Script.DotNetScriptEngine.Compile(ArrayList references, String language, String source, String url) in dotnetscriptengine.cs:line 66"

但程序的运行程序的权限是fulltrust的，而若GetEvidence(String Url)函数若是加载evidence.AddHost(Zone.CreateFromUrl(url));
是正常通过的。郁闷中，为何？