DataTable转Entity(Emit版)

Emit就是快啊,我有做测试

30000条数据,直接发射的话7秒多,Emit1.2秒左右

先记下来，有空了研究

public static class NewClas
    {

                public static List<T> ToList<T>(DataTable dt)
        {
            List<T> list = new List<T>();
            if (dt == null) return list;
            DataTableEntityBuilder<T> eblist = DataTableEntityBuilder<T>.CreateBuilder(dt.Rows[0]);
            foreach (DataRow info in dt.Rows)
                list.Add(eblist.Build(info));
            dt.Dispose();
            dt = null;
            return list;
        }

        public class DataTableEntityBuilder<T>
        {
            private static readonly MethodInfo getValueMethod = typeof(DataRow).GetMethod("get_Item", new Type[] { typeof(int) });
            private static readonly MethodInfo isDBNullMethod = typeof(DataRow).GetMethod("IsNull", new Type[] { typeof(int) });
            private delegate T Load(DataRow dataRecord);

            private Load handler;
            private DataTableEntityBuilder() { }

            public T Build(DataRow dataRecord)
            {
                return handler(dataRecord);
            }

            public static DataTableEntityBuilder<T> CreateBuilder(DataRow dataRow)
            {
                DataTableEntityBuilder<T> dynamicBuilder = new DataTableEntityBuilder<T>();
                DynamicMethod method = new DynamicMethod("DynamicCreateEntity", typeof(T), new Type[] { typeof(DataRow) }, typeof(T), true);
                ILGenerator generator = method.GetILGenerator();
                LocalBuilder result = generator.DeclareLocal(typeof(T));
                generator.Emit(OpCodes.Newobj, typeof(T).GetConstructor(Type.EmptyTypes));
                generator.Emit(OpCodes.Stloc, result);

                for (int index = 0; index < dataRow.ItemArray.Length; index++)
                {
                    PropertyInfo propertyInfo = typeof(T).GetProperty(dataRow.Table.Columns[index].ColumnName);
                    Label endIfLabel = generator.DefineLabel();
                    if (propertyInfo != null && propertyInfo.GetSetMethod() != null)
                    {
                        generator.Emit(OpCodes.Ldarg_0);
                        generator.Emit(OpCodes.Ldc_I4, index);
                        generator.Emit(OpCodes.Callvirt, isDBNullMethod);
                        generator.Emit(OpCodes.Brtrue, endIfLabel);
                        generator.Emit(OpCodes.Ldloc, result);
                        generator.Emit(OpCodes.Ldarg_0);
                        generator.Emit(OpCodes.Ldc_I4, index);
                        generator.Emit(OpCodes.Callvirt, getValueMethod);
                        generator.Emit(OpCodes.Unbox_Any, propertyInfo.PropertyType);
                        generator.Emit(OpCodes.Callvirt, propertyInfo.GetSetMethod());
                        generator.MarkLabel(endIfLabel);
                    }
                }
                generator.Emit(OpCodes.Ldloc, result);
                generator.Emit(OpCodes.Ret);
                dynamicBuilder.handler = (Load)method.CreateDelegate(typeof(Load));
                return dynamicBuilder;
            }
        }
    }