Изменения документа Сценарии

Сводка

• Свойства страницы (1 изменено, 0 добавлено, 0 удалено)

Подробности

Свойства страницы

Содержимое

...	...	@@ -13,14 +13,8 @@
13	13	|(% style="width:394px" %) |(% style="width:1090px" %)(((
14	14	How do I set a field value in an C# Expression tree?
15	15	[[https:~~/~~/stackoverflow.com/questions/321650/how-do-i-set-a-field-value-in-an-c-sharp-expression-tree>>https://stackoverflow.com/questions/321650/how-do-i-set-a-field-value-in-an-c-sharp-expression-tree]]
16		-
17		-How do you call a constructor via an expression tree on an existing object?
18		-[[https:~~/~~/stackoverflow.com/questions/16363838/how-do-you-call-a-constructor-via-an-expression-tree-on-an-existing-object>>https://stackoverflow.com/questions/16363838/how-do-you-call-a-constructor-via-an-expression-tree-on-an-existing-object]]
19		-
20		-How do I set a field value in an C# Expression tree?
21		-[[https:~~/~~/stackoverflow.com/questions/321650/how-do-i-set-a-field-value-in-an-c-sharp-expression-tree>>https://stackoverflow.com/questions/321650/how-do-i-set-a-field-value-in-an-c-sharp-expression-tree]]
22	22	)))
23		-|(% style="width:394px" %)Вызов конструктора|(% style="width:1090px" %){{code language="c#"}}var constructorInfo = t.GetConstructors().First(e => e.Attributes.HasFlag(MethodAttributes.Public));
	17	+|(% style="width:394px" %)Типизированый вызов конструктора|(% style="width:1090px" %){{code language="c#"}}var constructorInfo = type.GetConstructors().First(e => e.Attributes.HasFlag(MethodAttributes.Public));
24	24	var constructorParameter1 = Expression.Parameter(typeof(bool));
25	25	var constructorExp = Expression.New(constructorInfo, constructorParameter1);
26	26
...	...	@@ -34,20 +34,111 @@
34	34	How do you call a constructor via an expression tree on an existing object?
35	35	[[https:~~/~~/stackoverflow.com/questions/16363838/how-do-you-call-a-constructor-via-an-expression-tree-on-an-existing-object>>https://stackoverflow.com/questions/16363838/how-do-you-call-a-constructor-via-an-expression-tree-on-an-existing-object]]
36	36	)))
	31	+|(% style="width:394px" %)Нетипизированый вызов|(% style="width:1090px" %)(((
	32	+|{{code language="c#"}}public delegate object ConstructorDelegate(object[]? Args);
37	37
38		-==== ====
	34	+public static ConstructorDelegate GetConstructorWithArgsDelegate(
	35	+ ConstructorInfo constructorInfo)
	36	+{
	37	+ParameterExpression constructorParameters = Expression.Parameter(typeof(object?[]));
39	39
40		-==== ====
	39	+Expression[] parameterExpressions;
	40	+{
	41	+ ParameterInfo[] parametersInfos = constructorInfo.GetParameters();
	42	+ parameterExpressions = new Expression[parametersInfos.Length];
41	41
42		-==== ====
	44	+ for (int i = 0; i < parametersInfos.Length; i++)
	45	+ {
	46	+ ConstantExpression ithIndex = Expression.Constant(i);
	47	+ BinaryExpression ithParameter = Expression.ArrayIndex(
	48	+ constructorParameters,
	49	+ ithIndex);
	50	+ UnaryExpression unboxedIthParameter = Expression.Convert(
	51	+ ithParameter,
	52	+ parametersInfos[i].ParameterType
	53	+ );
	54	+ parameterExpressions[i] = unboxedIthParameter;
	55	+ }
	56	+}
43	43
	58	+NewExpression constructorCallExp = Expression.New(
	59	+ constructorInfo,
	60	+ parameterExpressions);
44	44
45		-----
	62	+var convertResultExp = Expression.Convert(
	63	+ constructorCallExp,
	64	+ typeof(object)
	65	+ );
46	46
47		-==== ====
	67	+var constructorHandler = Expression
	68	+ .Lambda<ConstructorDelegate>(
	69	+ convertResultExp,
	70	+ constructorParameters
	71	+ )
	72	+ .Compile();
48	48
	74	+return constructorHandler;
	75	+}{{/code}}|C# Expression tree: object array to Expression.New() parameters
	76	+[[https:~~/~~/stackoverflow.com/questions/67968927/c-sharp-expression-tree-object-array-to-expression-new-parameters>>https://stackoverflow.com/questions/67968927/c-sharp-expression-tree-object-array-to-expression-new-parameters]]
	77	+|{{code language="c#"}}public delegate object? MethodDelegate(object instance, object[]? Args);
49	49
50		-----
	79	+public static MethodDelegate GetMethodWithArgsDelegate(
	80	+ MethodInfo methodInfo,
	81	+ Type instanceType)
	82	+{
	83	+ParameterExpression instanceParameter = Expression.Parameter(typeof(object));
	84	+ParameterExpression methodParameters = Expression.Parameter(typeof(object?[]));
51	51
	86	+Expression instanceExp;
	87	+Expression[] parameterExpressions;
	88	+{
	89	+ instanceExp = Expression.Convert(instanceParameter, instanceType);
52	52
53		-----
	91	+ ParameterInfo[] parametersInfos = methodInfo.GetParameters();
	92	+ parameterExpressions = new Expression[parametersInfos.Length];
	93	+
	94	+ for (int i = 0; i < parametersInfos.Length; i++)
	95	+ {
	96	+ ConstantExpression ithIndex = Expression.Constant(i);
	97	+ BinaryExpression ithParameter = Expression.ArrayIndex(
	98	+ methodParameters,
	99	+ ithIndex);
	100	+ UnaryExpression unboxedIthParameter = Expression.Convert(
	101	+ ithParameter,
	102	+ parametersInfos[i].ParameterType
	103	+ );
	104	+ parameterExpressions[i] = unboxedIthParameter;
	105	+ }
	106	+}
	107	+
	108	+var callExpression = Expression.Call(
	109	+ instanceExp,
	110	+ methodInfo,
	111	+ parameterExpressions
	112	+ );
	113	+
	114	+var convertResultExp = Expression.Convert(
	115	+ callExpression,
	116	+ typeof(object)
	117	+ );
	118	+
	119	+var callHandler = Expression
	120	+ .Lambda<MethodDelegate>(
	121	+ convertResultExp,
	122	+ instanceParameter,
	123	+ methodParameters
	124	+ )
	125	+ .Compile();
	126	+
	127	+return callHandler;
	128	+}{{/code}}|
	129	+
	130	+
	131	+)))
	132	+|(% style="width:394px" %)[[Generic enum to int>>doc:.Generic enum to int.WebHome]]|(% style="width:1090px" %)
	133	+
	134	+==== ====
	135	+
	136	+==== ====
	137	+
	138	+==== ====