玩转动态编译高级篇：三,实例属性的读取与设置

.method public hidebysig instance string AAA() cil managed
{.maxstack 8L_0000: call string blqw.IL.Demo.Program/MyClass::get_Name()L_0005: ret
}

.method private hidebysig instance string AAA(class blqw.IL.Demo.Program/MyClass my) cil managed
{.maxstack 8L_0000: ldarg.0 L_0001: callvirt instance string blqw.IL.Demo.Program/MyClass::get_Name()L_0006: ret
}

// 将索引为 0 的参数加载到计算堆栈上。
public static readonly OpCode Ldarg_0;

public static Funcstring> ILTest()
{var type &＃61; typeof(MyClass);var prop &＃61; type.GetProperty("Name");//反射属性var dm &＃61; new DynamicMethod("", typeof(string), new[] { typeof(MyClass) }, type);var il &＃61; dm.GetILGenerator();il.Emit(OpCodes.Ldarg_0);il.Emit(OpCodes.Callvirt, prop.GetGetMethod());il.Emit(OpCodes.Ret);return (Funcstring>)dm.CreateDelegate(typeof(Funcstring>));
}

.method private hidebysig instance void AAA(class blqw.IL.Demo.Program/MyClass my, string name) cil managed
{.maxstack 8L_0000: ldarg.0 L_0001: ldarg.1 L_0002: callvirt instance void blqw.IL.Demo.Program/MyClass::set_Name(string)L_0007: ret
}

public static Actionstring> ILTest()
{var type &＃61; typeof(MyClass);var prop &＃61; type.GetProperty("Name");//反射属性var dm &＃61; new DynamicMethod("", null, new[] { typeof(MyClass), typeof(string) }, type);var il &＃61; dm.GetILGenerator();il.Emit(OpCodes.Ldarg_0);il.Emit(OpCodes.Ldarg_1);il.Emit(OpCodes.Callvirt, prop.GetSetMethod());il.Emit(OpCodes.Ret);return (Actionstring>)dm.CreateDelegate(typeof(Actionstring>));
}

public delegate void PropertySetter(object instance, object value);
public static PropertySetter CreateSetter(PropertyInfo property)
{var type &＃61; property.DeclaringType;var dm &＃61; new DynamicMethod("", null, new[] { typeof(object), typeof(object) }, type);//&＃61;&＃61;&＃61; IL &＃61;&＃61;&＃61;var il &＃61; dm.GetILGenerator();il.Emit(OpCodes.Ldarg_0);il.Emit(OpCodes.Ldarg_1);if (property.PropertyType.IsValueType)//判断属性类型是否是值类型
{il.Emit(OpCodes.Unbox,property.PropertyType);//如果是值类型就拆箱
}else{il.Emit(OpCodes.Castclass, property.PropertyType);//否则强转
}il.Emit(OpCodes.Callvirt, property.GetSetMethod());il.Emit(OpCodes.Ret);//&＃61;&＃61;&＃61; IL &＃61;&＃61;&＃61;return (PropertySetter)dm.CreateDelegate(typeof(PropertySetter));
}

public class ObjectProperty
{public PropertyInfo Info { get; set; }public PropertySetter Setter { get; set; }
}

static readonly Dictionary<Type, ObjectProperty[]> Cache &＃61; new Dictionary<Type, ObjectProperty[]>();public static ObjectProperty[] GetProperties(Type type)
{ObjectProperty[] arr;if (Cache.TryGetValue(type, out arr))//优先从缓存中获取
{return arr;}PropertyInfo[] ps &＃61; type.GetProperties(); arr &＃61; new ObjectProperty[ps.Length];for (int i &＃61; 0; i ){ObjectProperty op &＃61; new ObjectProperty();op.Info &＃61; ps[i];op.Setter &＃61; CreateSetter(op.Info); //之前定义的方法arr[i] &＃61; op;}Cache.Add(type, arr); //加入缓存return arr;
}

public static List ConvertToModels(DataSet ds)where T : new()
{var prop &＃61; ObjectProperty.GetProperties(typeof(T));List list &＃61; new List(ds.Tables[0].Rows.Count);var cols &＃61; ds.Tables[0].Columns;foreach (DataRow row in ds.Tables[0].Rows){T m &＃61; new T();foreach (var p in prop){if (cols.Contains(p.Info.Name)){var val &＃61; row[p.Info.Name];if ((val is DBNull) &＃61;&＃61; false){p.Setter(m, val);}}}list.Add(m);}return list;
}