我试图在运行时生成一个新的类/对象。Reflection.Emit throws BadImageFormatException
在阅读How to create a private property using PropertyBuilder后,我设法实现了每一项操作,一切都像我需要的一样。
但只要我尝试实例化我的新目标,即时接收BadImageFormatException
这似乎是一个类似的问题,但没有解决Is there any way to instrument System.Reflection.Emit?
这里我的代码:
领域:
internal class Field {
public string FieldName;
public Type FieldType;
public string Value;
}
发电机组代码:
var xx = new List<Field>(new[] { new Field { FieldName = "Name", FieldType = typeof(string), Value = "Hello World" },
new Field { FieldName = "Id", FieldType = typeof(int), Value = "1" } });
this.DoVodoo(xx);
魔术
private dynamic DoVodoo(IEnumerable<Field> fields) {
var aName = new AssemblyName("DynamicAssemblyExample");
var ab = AppDomain.CurrentDomain.DefineDynamicAssembly(aName, AssemblyBuilderAccess.RunAndSave);
var mb = ab.DefineDynamicModule(aName.Name, aName.Name + ".dll");
// Create class with all needed Properties
var tb = mb.DefineType("ParamRow", TypeAttributes.Public, typeof(object));
foreach (var field in fields) {
var pb = tb.DefineProperty(field.FieldName, PropertyAttributes.None, CallingConventions.HasThis, field.FieldType, null);
var getSetAttr = MethodAttributes.Public | MethodAttributes.SpecialName | MethodAttributes.HideBySig;
// Define the "get" accessor method for the Property.
var custNameGetPropMthdBldr = tb.DefineMethod($"get_{field.FieldName}", getSetAttr, typeof(string), Type.EmptyTypes);
var custNameGetIL = custNameGetPropMthdBldr.GetILGenerator();
custNameGetIL.Emit(OpCodes.Ldarg_0);
custNameGetIL.Emit(OpCodes.Ldfld, custNameGetPropMthdBldr);
custNameGetIL.Emit(OpCodes.Ret);
// Define the "set" accessor method for CustomerName.
var custNameSetPropMthdBldr = tb.DefineMethod($"set_{field.FieldName}", getSetAttr, null, new[] { typeof(string) });
var custNameSetIL = custNameSetPropMthdBldr.GetILGenerator();
custNameSetIL.Emit(OpCodes.Ldarg_0);
custNameSetIL.Emit(OpCodes.Ldarg_1);
//custNameSetIL.Emit(OpCodes.Stfld, custNameGetPropMthdBldr);
custNameSetIL.Emit(OpCodes.Stfld, custNameSetPropMthdBldr);
custNameSetIL.Emit(OpCodes.Ret);
// Last, we must map the two methods created above to our PropertyBuilder to
// their corresponding behaviors, "get" and "set" respectively.
pb.SetGetMethod(custNameGetPropMthdBldr);
pb.SetSetMethod(custNameSetPropMthdBldr);
}
var finalType = tb.CreateType();
var result = new List<object>();
foreach (var field in fields) {
var inst = ab.CreateInstance(finalType.Name);
finalType.GetProperty(field.FieldName, BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic).SetValue(inst, field.Value); //<-- Here comes the trouble
result.Add(inst);
}
return result;}
任何帮助表示赞赏如何实例化我的新创建的类型ParamRow
。
Bonus-Question: 为什么会有BadImageFormatException
?
附加信息:
- 的.Net框架4.6.1
- 编译器的目标是86
- 从此再也
Reflection.Emit
前
我即将有一个调试器看一下,看能不能找到这个错误,但是:如果你想避免他们和获得良好的错误信息的好方法,尝试[印记](HTTPS://www.nuget。组织/包/印记/) - 它是围绕IL发出(但在概念上相同)的包装,并且被设计成使它很难失败(或者至少,很容易弄清楚它为什么失败) –