我在運行時使用反射創建類,基於ClassName和屬性列表,它們是實現INotifyPropertyChanged和OnPropertyChanged的父類「DataObject」的子類,但是當我試圖通過下面的方法來設置屬性,我得到一個「場令牌超出範圍」的異常:OnpropertyChanged在運行時添加屬性設置器
private void dataGrid_AddingNewItem(object sender, AddingNewItemEventArgs e)
{
object obj = Activator.CreateInstance(currentType);
PropertyInfo[] properties = obj.GetType().GetProperties();
try
{
foreach (PropertyInfo prop in properties)
{
if (prop.PropertyType == typeof(string) && prop.CanWrite)
{ prop.SetValue(obj, "-", null); }
//else
//{ prop.SetValue(obj, 0, null); }
}
}
catch (Exception ex)
{
if (ex.InnerException != null)
{
throw ex.InnerException;
}
}
e.NewItem = obj;
}
這就是我想每個屬性的工作(LastChange是從父類的靜態字符串):
public string Provaa { get { return provaa; }
set { LastChange = ToString(); provaa = value; OnPropertyChanged("Provaa"); } }
,這是這是怎麼翻譯成MSIL:
.method public hidebysig specialname instance void
set_Provaa(string 'value') cil managed
{
// Code size 32 (0x20)
.maxstack 8
IL_0000: nop
IL_0001: ldarg.0
IL_0002: callvirt instance string [mscorlib]System.Object::ToString()
IL_0007: stsfld string EYBDataManager.DataObject::LastChange
IL_000c: ldarg.0
IL_000d: ldarg.1
IL_000e: stfld string EYBDataManager.Prova::provaa
IL_0013: ldarg.0
IL_0014: ldstr "Provaa"
IL_0019: call instance void EYBDataManager.DataObject::OnPropertyChanged(string)
IL_001e: nop
IL_001f: ret
} // end of method Prova::set_Provaa
而且最後這是我正在試圖重新創建使用反射:
MethodBuilder currSetPropMthdBldr = typeBuilder.DefineMethod("set_value", GetSetAttr, null, new Type[] { prop.ActualType });
ILGenerator currSetIL = currSetPropMthdBldr.GetILGenerator();
currSetIL.Emit(OpCodes.Ldarg_0);
currSetIL.Emit(OpCodes.Callvirt, typeof(Object).GetMethod("ToString"));
currSetIL.Emit(OpCodes.Stsfld, typeof(DataObject).GetField("LastChange", BindingFlags.Static | BindingFlags.Public);
currSetIL.Emit(OpCodes.Ldarg_0);
currSetIL.Emit(OpCodes.Ldarg_1);
currSetIL.Emit(OpCodes.Stfld, field);
currSetIL.Emit(OpCodes.Ldarg_0);
currSetIL.Emit(OpCodes.Ldstr, propertyName);
currSetIL.Emit(OpCodes.Callvirt, typeof(DataObject).GetMethod("OnPropertyChanged", new Type[1] { typeof(string) }));
currSetIL.Emit(OpCodes.Ret);
這是「CreateClass」方法的一部分:
public static void CreateClass(string className, List<PropertyTemplate> properties)
{
AssemblyName assemblyName = new AssemblyName();
assemblyName.Name = "tmpAssembly";
AssemblyBuilder assemblyBuilder = System.Threading.Thread.GetDomain().DefineDynamicAssembly(assemblyName, AssemblyBuilderAccess.Run);
ModuleBuilder module = assemblyBuilder.DefineDynamicModule("tmpModule");
TypeBuilder typeBuilder = module.DefineType(className, TypeAttributes.Public | TypeAttributes.Class, typeof(DataObject));
foreach (PropertyTemplate prop in properties)
{
string propertyName = prop.Name;
FieldBuilder field = typeBuilder.DefineField("p_" + propertyName, prop.ActualType, FieldAttributes.Private);
PropertyBuilder property = typeBuilder.DefineProperty(propertyName, PropertyAttributes.None, prop.ActualType, new Type[] { prop.ActualType });
MethodAttributes GetSetAttr = MethodAttributes.Public | MethodAttributes.SpecialName | MethodAttributes.HideBySig;
MethodBuilder currGetPropMthdBldr = typeBuilder.DefineMethod("get_value", GetSetAttr, prop.ActualType, Type.EmptyTypes);
ILGenerator currGetIL = currGetPropMthdBldr.GetILGenerator();
currGetIL.Emit(OpCodes.Ldarg_0);
currGetIL.Emit(OpCodes.Ldfld, field);
currGetIL.Emit(OpCodes.Ret);
ILGenerator currSetIL = currSetPropMthdBldr.GetILGenerator();
currSetIL.Emit(OpCodes.Ldarg_0);
currSetIL.Emit(OpCodes.Callvirt, typeof(Object).GetMethod("ToString"));
currSetIL.Emit(OpCodes.Stsfld, DataObject.LastChange);
currSetIL.Emit(OpCodes.Ldarg_0);
currSetIL.Emit(OpCodes.Ldarg_1);
currSetIL.Emit(OpCodes.Stfld, field);
currSetIL.Emit(OpCodes.Ldarg_0);
currSetIL.Emit(OpCodes.Ldstr, propertyName);
currSetIL.Emit(OpCodes.Callvirt, typeof(DataObject).GetMethod("OnPropertyChanged", new Type[1] { typeof(string) }));
currSetIL.Emit(OpCodes.Ret);
property.SetGetMethod(currGetPropMthdBldr);
property.SetSetMethod(currSetPropMthdBldr);
}
Type genType = typeBuilder.CreateType();
if (Templates.ContainsKey(className))
Templates[className] = genType;
else
Templates.Add(className, genType);
}
我懷疑我需要在設置值時指定類的名稱和模塊名稱,但不知道如何,儘管Activator使用所有正確的屬性創建類實例,所以pr當建立SetMethod的時候,我可能會犯一些錯誤,有人能幫助我嗎?
編輯父類:
public class DataObject : INotifyPropertyChanged
{
public static string LastChange = "";
public void OnPropertyChanged(string propertyName)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
public override string ToString()
{
string tostring = "|";
PropertyInfo[] properties = this.GetType().GetProperties();
foreach (PropertyInfo prop in properties)
{
tostring += " " + prop.GetValue(this, null) + " |";
}
return tostring;
}
public event PropertyChangedEventHandler PropertyChanged;
}
你好,謝謝你的回答,我修改了代碼之後你的建議,但我仍然嘗試設置值時,出現「字段標記超出範圍」異常,我也添加了父類,如果它可能是有用的 –
@EatYourB eetS吸氣劑的作用?如果是,請嘗試在不設置靜態字段的情況下發射setter。我直到明天都不能檢查它。讓我知道它的工作。 –
是的,現在它沒有這3行 'currSetIL.Emit(OpCodes.Ldarg_0); (OpCodes.Call,typeof(DataObject).GetMethod(「ToString」,new Type [0])); currSetIL.Emit(OpCodes.Stsfld,DataObject.LastChange);' 我猜的第三個特別的問題 –