private static FastSetValueHandler SetValueInvoker(FieldInfo field)
{
//定义一个没有名字的动态方法
DynamicMethod dynamicMethod = new DynamicMethod(String.Empty, null, new Type[] { typeof(Object), typeof(Object) }, field.DeclaringType.Module, true);
ILGenerator il = dynamicMethod.GetILGenerator();
EmitHelper help = new EmitHelper(il);
// 必须考虑对象是值类型的情况，需要拆箱
// 其它地方看到的程序从来都没有人处理
// 值类型是不支持这样子赋值的，暂时没有找到更好的替代方法
help.Ldarg(0)
.CastFromObject(field.DeclaringType)
.Ldarg(1);
//il.Emit(OpCodes.Ldarg_0);
//help.CastFromObject(field.DeclaringType);
//il.Emit(OpCodes.Ldarg_1);
MethodInfo method = GetMethod(field.FieldType);
if (method != null)
{
//// 使用Convert.ToInt32(value)
//il.EmitCall(OpCodes.Call, method, null);
help.Call(method);
}
else
{
//if (field.FieldType.IsValueType)
// il.Emit(OpCodes.Unbox_Any, field.FieldType);
//else
// il.Emit(OpCodes.Castclass, field.FieldType);
help.CastFromObject(field.FieldType);
}
il.Emit(OpCodes.Stfld, field);
il.Emit(OpCodes.Ret);
return((FastSetValueHandler)dynamicMethod.CreateDelegate(typeof(FastSetValueHandler)));
}
private static FastGetValueHandler GetValueInvoker(MethodInfo method)
{
//定义一个没有名字的动态方法
DynamicMethod dynamicMethod = new DynamicMethod(String.Empty, typeof(Object), new Type[] { typeof(Object) }, method.DeclaringType.Module, true);
ILGenerator il = dynamicMethod.GetILGenerator();
EmitHelper help = new EmitHelper(il);
//if (!method.IsStatic) il.Emit(OpCodes.Ldarg_0);
if (!method.IsStatic)
{
help.Ldarg(0).CastFromObject(method.DeclaringType);
}
// 目标方法没有参数
help.Call(method)
.BoxIfValueType(method.ReturnType)
.Ret();
return((FastGetValueHandler)dynamicMethod.CreateDelegate(typeof(FastGetValueHandler)));
}
static void GetMethodInvoker(ILGenerator il, MethodInfo method)
{
EmitHelper help = new EmitHelper(il);
Type retType = method.ReturnType;
//if (!method.IsStatic) il.Emit(OpCodes.Ldarg_0);
if (!method.IsStatic)
{
help.Ldarg(0).CastFromObject(method.DeclaringType);
}
// 方法的参数数组放在动态方法的第二位，所以是1
help.PushParams(1, method)
.Call(method)
.BoxIfValueType(retType);
//处理返回值，如果调用的方法没有返回值，则需要返回一个空
if (retType == null || retType == typeof(void))
{
help.Ldnull().Ret();
}
else
{
help.Ret();
}
//调用目标方法
//if (method.IsVirtual)
// il.EmitCall(OpCodes.Callvirt, method, null);
//else
// il.EmitCall(OpCodes.Call, method, null);
////处理返回值
//if (method.ReturnType == typeof(void))
// il.Emit(OpCodes.Ldnull);
//else if (method.ReturnType.IsValueType)
// il.Emit(OpCodes.Box, method.ReturnType);
//il.Emit(OpCodes.Ret);
}
private static FastHandler GetConstructorInvoker(Type target, ConstructorInfo constructor)
{
// 定义一个没有名字的动态方法。
// 关联到模块，并且跳过JIT可见性检查，可以访问所有类型的所有成员
DynamicMethod dynamicMethod = new DynamicMethod(String.Empty, typeof(Object), new Type[] { typeof(Object[]) }, target.Module, true);
{
ILGenerator il = dynamicMethod.GetILGenerator();
EmitHelper help = new EmitHelper(il);
if (target.IsValueType)
{
help.NewValueType(target).BoxIfValueType(target).Ret();
}
else if (target.IsArray)
{
help.PushParams(0, new Type[] { typeof(Int32) }).NewArray(target.GetElementType()).Ret();
}
else
{
help.PushParams(0, constructor).NewObj(constructor).Ret();
}
}
#if DEBUG
//SaveIL(dynamicMethod, delegate(ILGenerator il)
// {
// EmitHelper help = new EmitHelper(il);
// if (target.IsValueType)
// help.NewValueType(target).BoxIfValueType(target).Ret();
// else if (target.IsArray)
// help.PushParams(0, new Type[] { typeof(Int32) }).NewArray(target.GetElementType()).Ret();
// else
// help.PushParams(0, constructor).NewObj(constructor).Ret();
// });
#endif
return((FastHandler)dynamicMethod.CreateDelegate(typeof(FastHandler)));
}